10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended June 30, 2017

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ______ to ______

Commission File No.:001-34079

Rexahn Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

Delaware	11-3516358
(State or Other Jurisdiction of Incorporation or Organization)	(I.R.S. Employer Identification No.)

15245 Shady Grove Road, Suite 455

Rockville, MD 20850

(Address of Principal Executive Offices, Including Zip Code)

Telephone: (240) 268-5300

(Registrant’s Telephone Number, Including Area Code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☑  No ☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ☑ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definition of “accelerated filer,” “large accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer	☐		Accelerated filer	☑
Non-accelerated filer	☐	(Do not check if a smaller reporting company)	Smaller reporting company	☐
			Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act) Yes ☐  No ☑

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date: 28,459,805shares as of August 4, 2017.

REXAHN PHARMACEUTICALS, INC.

TABLE OF CONTENTS

			Page
PART I	FINANCIAL INFORMATION		1
Item 1	Financial Statements (Unaudited)		1
	1)	Condensed Balance Sheet as of June 30, 2017 and December 31, 2016	1
	2)	Condensed Statement of Operations for the three and six months ended June 30, 2017 and 2016	2
	3)	Condensed Statement of Comprehensive Income (Loss) for the three and six months ended June 30, 2017 and 2016	3
	4)	Condensed Statement of Cash Flows for the six months ended June 30, 2017 and 2016	4
	5)	Notes to the Condensed Financial Statements	5
Item 2	Management’s Discussion and Analysis of Financial Condition and Results of Operations		25
Item 3	Quantitative and Qualitative Disclosures About Market Risk		33
Item 4	Controls and Procedures		33
PART II	OTHER INFORMATION		34
Item 1A	Risk Factors		34
Item 2	Unregistered Sales of Equity Securities and Use of Proceeds		34
Item 5	Other Information		34
Item 6	Exhibits		34
SIGNATURES			35

PART I. Financial Information

Item 1. Financial Statements

REXAHN PHARMACEUTICALS, INC.

Condensed Balance Sheet

(Unaudited)

	June 30, 2017			December 31, 2016
ASSETS
Current Assets:
Cash and cash equivalents	$	8,790,519		$	11,578,473
Marketable securities		17,986,160			8,737,107
Prepaid expenses and other current assets		1,199,641			608,517
Total Current Assets		27,976,320			20,924,097
Security Deposits		30,785			30,785
Equipment, Net		86,610			88,650
Total Assets	$	28,093,715		$	21,043,532
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current Liabilities:
Accounts payable and accrued expenses	$	1,917,739		$	1,882,500
Deferred Research and Development Arrangement		412,500			450,000
Other Liabilities		65,812			79,204
Warrant Liabilities		9,796,591			1,573,366
Total Liabilities		12,192,642			3,985,070
Commitments and Contingencies (note 14)
Stockholders’ Equity:
Preferred stock, par value $0.0001, 10,000,000 authorized shares, none issued and outstanding		-			-
Common stock, par value $0.0001, 50,000,000 authorized shares, 28,452,305 and 23,736,878 issued and outstanding		2,845			2,374
Additional paid-in capital		151,612,110			132,086,419
Accumulated other comprehensive loss		(25,705	)		(6,122	)
Accumulated deficit		(135,688,177	)		(115,024,209	)
Total Stockholders’ Equity		15,901,073			17,058,462
Total Liabilities and Stockholders’ Equity	$	28,093,715		$	21,043,532

(See accompanying notes to the condensed financial statements)

1

REXAHN PHARMACEUTICALS, INC.

Condensed Statement of Operations

(Unaudited)

	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2017			2016			2017			2016
Revenues:	$	-		$	-		$	-		$	-
Expenses:
General and administrative		1,739,663			1,675,749			3,430,509			3,071,155
Research and development		2,544,262			2,237,033			4,806,657			5,705,607
Total Expenses		4,283,925			3,912,782			8,237,166			8,776,762
Loss from Operations		(4,283,925	)		(3,912,782	)		(8,237,166	)		(8,776,762	)
Other Income (Expense)
Interest income		42,782			28,868			74,579			57,738
Unrealized gain (loss) on fair value of warrants		5,521,249			2,118,090			(12,168,331	)		2,974,045
Financing expense		(333,050	)		-			(333,050	)		(169,887	)
Total Other Income (Expense)		5,230,981			2,146,958			(12,426,802	)		2,861,896
Net Income (Loss) Before Provision for Income Taxes		947,056			(1,765,824	)		(20,663,968	)		(5,914,866	)
Provision for income taxes		-			-			-			-
Net Income (Loss)	$	947,056		$	(1,765,824	)	$	(20,663,968	)	$	(5,914,866	)
Net income (loss) per share, basic	$	0.04		$	(0.08	)	$	(0.83	)	$	(0.28	)
Net income (loss) per share, diluted	$	0.03		$	(0.08	)	$	(0.83	)	$	(0.28	)
Weighted average number of shares outstanding, basic		26,001,797			21,318,433			24,932,705			20,788,557
Weighted average number of shares outstanding, diluted		28,265,440			21,318,433			24,932,705			20,788,557

(See accompanying notes to the condensed financial statements)

2

REXAHN PHARMACEUTICALS, INC.

Condensed Statement of Comprehensive Income (Loss)

(Unaudited)

	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2017			2016			2017			2016
Net Income (Loss)	$	947,056		$	(1,765,824	)	$	(20,663,968	)	$	(5,914,866	)
Unrealized (loss) gain on available-for-sale securities		(19,379	)		3,733			(19,583	)		20,368
Comprehensive Income (Loss)	$	927,677		$	(1,762,091	)	$	(20,683,551	)	$	(5,894,498	)

(See accompanying notes to the condensed financial statements)

3

REXAHN PHARMACEUTICALS, INC.

Condensed Statement of Cash Flows

(Unaudited)

	For the Six Months Ended June 30,
	2017			2016
Cash Flows from Operating Activities:
Net loss	$	(20,663,968	)	$	(5,914,866	)
Adjustments to reconcile net loss to net cash used in operating activities:
Compensatory stock		12,750			64,949
Depreciation and amortization		19,950			15,053
Amortization of premiums and discounts on marketable securities, net		20,024			22,315
Stock-based compensation		562,392			694,187
Amortization of deferred research and development arrangement		(37,500	)		(37,500	)
Unrealized loss (gain) on fair value of warrants		12,168,331			(2,974,045	)
Financing expense		333,050			169,887
Amortization of deferred lease incentive		(6,222	)		(6,222	)
Deferred lease expenses		(7,170	)		(5,203	)
Changes in assets and liabilities:
Prepaid expenses and other assets		(591,124	)		225,735
Accounts payable and accrued expenses		(78,492	)		(866,651	)
Net Cash Used in Operating Activities		(8,267,979	)		(8,612,361	)
Cash Flows from Investing Activities:
Purchase of equipment		(17,910	)		(7,511	)
Purchase of marketable securities		(15,008,660	)		(1,721,760	)
Redemption of marketable securities		5,720,000			3,440,000
Net Cash (Used in) Provided by  Investing Activities		(9,306,570	)		1,710,729
Cash Flows from Financing Activities:
Issuance of common stock and units, net of issuance costs		9,355,002			4,580,187
Proceeds from exercise of stock warrants		5,354,093			-
Proceeds from exercise of stock options		77,500			-
Net Cash Provided by Financing Activities		14,786,595			4,580,187
Net Decrease in Cash and Cash Equivalents		(2,787,954	)		(2,321,445	)
Cash and Cash Equivalents – beginning of period		11,578,473			10,199,440
Cash and Cash Equivalents – end of period	$	8,790,519		$	7,877,995
Supplemental Cash Flow Information
Non-cash financing and investing activities:
Warrants issued	$	4,107,488		$	2,575,860
Warrant liability extinguishment from exercise of warrants	$	8,052,594		$	-
Offering costs included in accounts payable and accrued expenses	$	113,731		$	-

(See accompanying notes to the condensed financial statements)

4

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

1. Operations and Organization

Operations

Rexahn Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, is a biopharmaceutical company whose principal operations are the discovery, development and commercialization of innovative treatments for cancer.  The Company had an accumulated deficit of $135,688,177 at June 30, 2017 and anticipates incurring losses through fiscal year 2017 and beyond.  The Company has not yet generated commercial revenues and has funded its operating losses to date through the sale of shares of its common stock and warrants to purchase shares of its common stock, convertible debt, interest income from cash, cash equivalents and marketable securities, and proceeds from reimbursed research and development costs.  The Company believes that its cash, cash equivalents, and marketable securities will be sufficient to cover its cash flow requirements for its current activities for at least the next 12 months from the date these financial statements were issued.  Management believes it has the capability of managing the Company’s operations within existing cash available by focusing on select research and development activities, selecting projects in conjunction with potential financings and milestones, and efficiently managing the Company’s general and administrative affairs.

Basis of Presentation

The accompanying unaudited condensed financial statements of the Company have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission for interim financial information.  Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete financial statements.  In the opinion of the Company’s management, all adjustments (consisting of only normal recurring accruals) considered necessary for a fair presentation of the Company’s financial position as of June 30, 2017 and December 31, 2016 and of the results of operations and comprehensive income (loss) for the three and six months ended June 30, 2017 and 2016 and cash flows for the six months ended June 30, 2017 and 2016 have been included.  Operating results for the three and six months ended June 30, 2017 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2017. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the “2016 Form 10-K”).  Information included in the condensed balance sheet as of December 31, 2016 has been derived from the Company’s audited financial statements for the year ended December 31, 2016 included in the 2016 Form 10-K.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future.  Actual results may ultimately differ from these estimates.  These estimates are reviewed periodically, and as adjustments become necessary, they are reported in earnings in the period in which they become available.

5

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

2. Recent Accounting Pronouncements Affecting the Company

Revenue from Contracts with Customers

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company should recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services, and provides a revenue recognition framework in accordance with this principle.  On August 12, 2015, the FASB issued ASU 2015-14, which defers the effective date of ASU 2014-09 by one year to December 15, 2017 for annual reporting periods beginning after that date and interim periods therein.  Early adoption of the standard is permitted.  The Company is currently evaluating the impact that the adoption of this guidance will have on its financial statements and future operating results.

Leases

In February 2016, the FASB issued ASU 2016-02, “Leases,” which requires an entity to recognize assets and liabilities arising from leases on the balance sheet and to provide additional disclosures about leasing arrangements.  ASU 2016-02 will be effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.

Compensation-Stock Compensation

In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation: Improvements to Employee Share Based Payment Accounting,” which includes multiple provisions intended to simplify various aspects of accounting for share-based payments.  The guidance is effective for reporting periods beginning after December 15, 2016, with early adoption permitted.  The Company adopted this guidance for the three months ended March 31, 2017.  This pronouncement did not have a material impact on the financial statements.

6

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

3. Marketable Securities

Marketable securities are considered “available-for-sale” in accordance with FASB Accounting Standards Codification (“ASC”) 320, “Debt and Equity Securities,” and thus are reported at fair value in the Company’s accompanying balance sheet, with unrealized gains and losses excluded from earnings and reported as a separate component of stockholders’ equity.  Amounts reclassified out of accumulated other comprehensive income (loss) into realized gains and losses are accounted for on the basis of specific identification and are included in other income or expense in the statement of operations.  The Company classifies such investments as current on the balance sheet as the investments are readily marketable and available for use in current operations.

The following table shows the Company’s marketable securities’ adjusted cost, gross unrealized gains and losses, and fair value by significant investment category as of June 30, 2017 and December 31, 2016:

	June 30, 2017
	Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial Paper	$	3,220,126	$	-	$	(4,796	)	$	3,215,330
Corporate Bonds		14,791,739		-		(20,909	)		14,770,830
Total Marketable Securities	$	18,011,865	$	-	$	(25,705	)	$	17,986,160

	December 31, 2016
	Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Certificates of Deposit	$	720,000	$	197	$	-		$	720,197
Commercial Paper		3,987,424		-		(1,684	)		3,985,740
Corporate Bonds		4,035,805		-		(4,635	)		4,031,170
Total Marketable Securities	$	8,743,229	$	197	$	(6,319	)	$	8,737,107

The Company typically invests in highly-rated securities, with the primary objective of minimizing the potential risk of principal loss.  As of June 30, 2017, the Company had three investments of commercial paper with an aggregate fair value of $3,215,330 and unrealized losses of $4,796, and 14 corporate bonds with an aggregate fair value of $13,770,830 and unrealized losses of $20,909, all of which have been unrealized losses for less than 12 months.  The Company does not intend to sell its marketable securities in an unrealized loss position.  Based upon these securities’ fair value relative to the cost, high ratings, and volatility of fair value, the Company considers the declines in market value of its marketable securities to be temporary in nature, does not consider any of its investments other-than-temporarily impaired, and anticipates that it will recover the entire amortized cost basis.

The amortized cost basis and fair value of marketable securities by contractual maturity are:

Maturity		Cost Basis	Fair Value
Less than 1 year	$	12,274,138		$	12,257,650
1 to 5 years		5,737,727			5,728,510
Total Marketable Securities	$	18,011,865		$	17,986,160

7

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

4. Prepaid Expenses and Other Current Assets

	June 30, 2017		December 31, 2016
Deposits on contracts	$	532,602	$	179,476
Prepaid expenses and other current assets		667,039		429,041
	$	1,199,641	$	608,517

Deposits on contracts consist of deposits on research and development contracts for services that had not been incurred as of the balance sheet date.  Prepaid expenses and other assets include prepaid general and administrative expenses, such as insurance, rent, investor relations fees and compensatory stock issued for services not yet incurred as of the balance sheet date.

5. Equipment, Net

	June 30, 2017			December 31, 2016
Furniture and fixtures	$	78,794		$	78,794
Office and computer equipment		118,358			113,932
Lab equipment		445,134			431,650
Leasehold improvements		133,762			133,762
Total equipment		776,048			758,138
Less: Accumulated depreciation and amortization		(689,438	)		(669,488	)
Net carrying amount	$	86,610		$	88,650

6. Accounts Payable and Accrued Expenses

	June 30, 2017		December 31, 2016
Trade payables	$	509,085	$	430,013
Accrued expenses		167,297		141,190
Accrued research and development contract costs		715,065		499,889
Payroll liabilities		526,292		811,408
	$	1,917,739	$	1,882,500

8

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

7. Deferred Research and Development Arrangement

Rexgene Biotech Co., Ltd.

In 2003, the Company entered into a collaborative research agreement with Rexgene Biotech Co., Ltd. (“Rexgene”), a shareholder.  Rexgene is engaged in the development of pharmaceutical products in Asia and has agreed to assist the Company with the research, development and clinical trials necessary for registration of the Company’s drug candidate Archexin® in Asia.  This agreement provides Rexgene with exclusive rights to license, sublicense, make, have made, use, sell and import Archexin in Asia.  In accordance with the agreement, Rexgene paid the Company a one-time fee of $1,500,000 in 2003.  The agreement terminates at the later of 20 years or the term of the patent.  The amortization reduces research and development expenses for the periods presented.

The Company is using 20 years as its basis for recognition and accordingly, research and development expenses were reduced by $18,750 and $37,500 for the three and six months ended June 30, 2017 and 2016, respectively.  The remaining $412,500 and $450,000 to be amortized at June 30, 2017 and December 31, 2016, respectively, is reflected as a deferred research and development arrangement on the balance sheet.  The payment from Rexgene is being used in the cooperative funding of the costs of development of Archexin. Royalties of 3% of net sales of licensed products will become payable by Rexgene to the Company on a quarterly basis once commercial sales of Archexin begin in Asia.  The product is still under development and commercial sales in Asia are not expected to begin until at least 2018.

9

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

8. Other Liabilities

Deferred Lease Incentive

In accordance with the Company’s office lease agreement, as amended and further discussed in Note 14, the Company has been granted leasehold improvement allowances from the lessor to be used for the construction cost of improvements to the leased property, which included architectural and engineering fees, government agency plan check, permit and other fees, sales and use taxes, testing and inspection costs and telephone and data cabling and wiring in the premises.  The Company accounted for the benefit of the leasehold improvement allowance as a reduction of rental expense over the term of the office lease.

The following table sets forth the cumulative deferred lease incentive:

	June 30, 2017			December 31, 2016
Deferred lease incentive	$	154,660		$	154,660
Less accumulated amortization		(129,773	)		(123,551	)
Balance	$	24,887		$	31,109

Deferred Office Lease Expense

The lease agreement, as amended, provided for an initial annual base rent with annual increases over the lease term.  The Company recognizes rental expense on a straight-line basis over the term of the lease, which resulted in a deferred rent liability of $40,925 and $48,095 as of June 30, 2017 and December 31, 2016, respectively.

9. Net Income (Loss) per Common Share

Basic income (loss) per common share is computed by dividing net income (loss) by the weighted average number of shares of common stock outstanding for the period.  Diluted loss per common share is computed by dividing net loss by the weighted average number of shares of common stock outstanding, plus the number of common share equivalents that would be dilutive.  As of June 30, 2017 and December 31, 2016, there were stock options, restricted stock units and warrants to acquire, in the aggregate, 7,280,637 and 7,142,728 shares of the Company’s common stock, respectively, that are potentially dilutive. However, with the exception of the three months ended June 30, 2017, diluted loss per share is the same as basic loss per share for all periods presented because the inclusion of common share equivalents would be anti-dilutive.  For the three months ended June 30, 2017, the dilutive effect of stock warrants, stock options and restricted stock units is 1,177,987, 1,031,356 and 54,300, respectively.

10

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

10. Common Stock

The following transactions occurred since December 31, 2016:

Reverse Stock Split

On May 5, 2017 the Company effected a one-for-ten reverse stock split of the outstanding shares of the Company’s common stock, together with a corresponding proportional reduction in the number of authorized shares of the Company’s capital stock.  Each ten shares of the Company’s common stock, par value $0.0001 per share, issued and outstanding at the effective time of the reverse stock split were reclassified and combined into one share of common stock par value $0.0001 per share. The number of shares of common stock and preferred stock the Company is authorized to issue was reduced to 50 million and 10 million, respectively.  All share and per share amounts of common stock, stock options, stock warrants and restricted stock units have been restated for all periods to give retroactive effect to the reverse stock split.  Accordingly, an amount equal to the par value of the decreased shares resulting from the reverse stock split was reclassified from “Common stock” to “Additional paid-in capital.”

Warrant Exercises

During the six months ended June 30, 2017, warrant holders exercised warrants to purchase shares of the Company’s common stock for cash of $5,354,093 and the Company issued 1,652,623 shares.

Stock Option Exercises

During the six months ended June 30, 2017, a stock option holder exercised options to purchase shares of the Company’s common stock for cash of $77,500 and the Company issued 25,000 shares.

Compensatory Shares

During the six months ended June 30, 2017, the Company issued 7,500 shares to a privately held investor relations firm in exchange for investor relations services.  The aggregate market value of the stock issued was $12,750.

11

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

Registered Direct Offering

On June 12, 2017 the Company closed a registered direct public offering of 3,030,304 shares of common stock and warrants to purchase up to 1,515,152 shares of common stock.  The common stock and warrants were sold in units, consisting of a share of common stock and a warrant to purchase 0.5 shares of common stock, at a price of $3.30 per unit, with an exercise price for the warrants of $4.00 per share.  The total gross proceeds of the offering were $10,000,003.  The warrants issued will become exercisable beginning six months after the closing date, and will remain exercisable until the five-year anniversary of the initial exercise date, and were recorded as liabilities at fair value.

A summary of the allocation of the proceeds of the offering is shown below:

Gross Proceeds:	$	10,000,003
Allocated to warrant liabilities		3,673,168
Allocated to common stock and additional paid-in capital		6,326,835
Total allocated gross proceeds:	$	10,000,003

The Company also issued warrants to purchase up to an aggregate 181,818 shares of common stock to the placement agent in the offering.  The closing costs for the offering of $1,193,052 included $434,320 for the placement agent warrants and $758,732 for placement agent and other fees.  Based on the estimated fair value of the stock and warrants in the units, the Company allocated $333,050 to financing expense for the warrants and $860,002 as stock issuance costs.

12

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

11. Stock-Based Compensation

As of June 30, 2017, the Company had 1,937,871 options to purchase common stock and 54,300 restricted stock units (“RSUs”) outstanding.

At the Company’s Annual Meeting of Shareholders held on June 10, 2013, the Company’s shareholders voted to approve the Rexahn Pharmaceuticals, Inc. 2013 Stock Option Plan (the “2013 Plan”).  Under the 2013 Plan, the Company grants equity awards to key employees, directors and consultants of the Company.  The Company initially reserved 1,700,000 shares of common stock for issuance pursuant to the 2013 Plan, and on April 11, 2017, the Company’s shareholders approved an increase of 1,700,000 shares of common stock reserved for issuance pursuant to the 2013 Plan. As of June 30, 2017, there were 1,540,871 options and 54,300 RSUs outstanding under the 2013 Plan, and 1,804,079 shares were available for issuance.

On August 5, 2003, the Company established a stock option plan (the “2003 Plan”).  Under the 2003 Plan, the Company granted stock options to key employees, directors and consultants of the Company.  With the adoption of the 2013 Plan, no new stock options may be issued under the 2003 Plan, but previously issued options under the 2003 Plan remain outstanding until their expiration.  As of June 30, 2017, there were 385,000 options outstanding under the 2003 Plan.

In March 2016, the Company granted to a third party an option to purchase up to 12,000 shares of the Company’s common stock.  These were the only Company stock options outstanding as of June 30, 2017, that were not issued pursuant to the 2013 Plan or the 2003 Plan.

Accounting for Awards

Stock-based compensation expense is the estimated fair value of options and RSUs granted amortized on a straight-line basis over the requisite vesting service period for the entire portion of the award. Total stock-based compensation recognized by the Company for the three and six months ended June 30, 2017 and 2016 is as follows:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2017		2016		2017		2016
Statement of operations line item:
General and administrative	$	207,587	$	224,786	$	395,898	$	440,113
Research and development		80,478		126,390		166,494		254,074
Total	$	288,065	$	351,176	$	562,392	$	694,187

No income tax benefit has been recognized in the statement of operations for stock-based compensation arrangements as the Company has provided for a 100% valuation allowance on its deferred tax assets.

13

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

Summary of Stock Option Transactions

There were 393,260 stock options granted at exercise prices ranging from $1.84 to $6.18 with an aggregate fair value of $620,185 during the six months ended June 30, 2017.  There were 448,707 stock options granted at exercise prices ranging from $2.70 to $3.70 with an aggregate fair value of $927,644 during the six months ended June 30, 2016.

The majority of the option grants to employees vest over a four-year period from the grant date. The vesting period is either (i) 30%, 30% and 40% on the first, second and third anniversaries of the grant date, respectively, or (ii) 25% each on the first four anniversaries of the grant date.  With the exception of the options granted in March 2016, which have a three-year term, options generally expire ten years from the date of grant. For the majority of grants to non-employee consultants of the Company, the vesting period is between one and three years, subject to the fulfillment of certain conditions in the individual stock agreements, or 100% upon the occurrence of certain events specified in the individual stock agreements.

The fair value of options at the date of grant was estimated using the Black-Scholes option pricing model.  The Company took into consideration guidance under ASC 718, “Compensation-Stock Compensation” and Staff Accounting Bulletin No. 107 (“SAB 107”) when reviewing and updating assumptions.  The expected volatility is based upon historical volatility of the Company’s stock.  The expected term is based upon the simplified method as allowed under SAB 107.

The assumptions made in calculating the fair values of options are as follows:

	Six Months Ended June 30,
	2017			2016
Black-Scholes assumptions
Expected dividend yield		0	%		0	%
Expected volatility		69-79	%		32-75	%
Risk free interest rate		1.8-2.0	%		0.6-1.4	%
Expected term (in years)	5.5-6 years			2-6 years

A summary of stock option activity for the six months ended June 30, 2017 is as follows:

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding, January 1, 2017		1,690,037		$	6.20	7.3 years	$	-
Granted		393,260			2.46
Exercised		(25,000	)		3.10
Expired		(15,000	)		16.07
Cancelled		(105,426	)		3.77
Outstanding, June 30, 2017		1,937,871		$	5.54	7.4 years	$	342,455
Exercisable, June 30, 2017		1,120,784		$	6.73	6.3 years	$	6,858

14

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

The total intrinsic value of options exercised was $97,872 for the three and six months ended June 30, 2017.  There were no stock options exercised during the three and six months ended June 30, 2016.  The weighted average fair value of the options granted was $1.58 and $2.06 for the six months ended June 30, 2017 and 2016, respectively.

A summary of the Company’s unvested options as of June 30, 2017 and changes during the six months ended June 30, 2017 is presented below:

	2017
	Number of Options			Weighted Average Fair Value at Grant Date
Unvested at January 1, 2017		897,123		$	3.21
Granted		393,260		$	1.58
Vested		(378,594	)	$	3.06
Cancelled		(94,702	)	$	2.15
Unvested at June 30, 2017		817,087		$	2.63

As of June 30, 2017 there was $1,749,516 of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average vesting period of 2.6 years.

Summary of Restricted Stock Unit Transactions

The Company began granting RSUs to employees in 2017.  There were 62,300 RSUs granted with an aggregate fair value of $114,632 during the six months ended June 30, 2017.  The fair value of an RSU award is the closing price of the Company’s common stock on the date of grant.

A summary of RSU activity for the six months ended June 30, 2017 is as follows:

	Number of RSUs			Weighted Average Grant Date Fair Value
Outstanding, January 1, 2017		-		$	-
Granted		62,300			1.84
Vested and Released		-			-
Cancelled		(8,000	)		1.84
Outstanding, June 30, 2017		54,300		$	1.84

As of June 30, 2017, there was $89,717 of total unrecognized compensation cost related to unvested RSUs which is expected to be recognized over a weighted average vesting period of 3.7 years.

15

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

12. Warrants

As of June 30, 2017, warrants to purchase up to 5,288,466 shares were outstanding, having exercise prices ranging from $3.00 to $12.80 and expiration dates ranging from December 4, 2017 to December 12, 2022.

	2017					2016
	Number of warrants			Weighted average exercise price		Number of warrants		Weighted average exercise price
Balance, January 1		5,452,691		$	4.92		2,649,199	$	7.97
Issued during the period		1,696,970		$	4.01		1,250,000	$	4.20
Exercised during the period		(1,861,195	)	$	3.51		-	$	-
Expired during the period		-		$	-		-	$	-
Balance, June 30		5,288,466		$	5.13		3,899,199	$	6.76

At June 30, 2017 the weighted average remaining contractual life of the outstanding warrants was 4.1 years.

The warrants issued to investors in the December 2012, November 2015, March 2016 and September 2016 offerings contain a provision for net cash settlement in the event of a fundamental transaction (contractually defined to include a merger, sale of substantially all assets, tender offer or share exchange).  Pursuant to the November 2015, March 2016, and September 2016 warrants, if fundamental transaction occurs, then the warrant holder has the option to receive cash, equal to the fair value of the remaining unexercised portion of the warrant.  The option is available to holders of the December 2012 warrants only if the consideration issued in the fundamental transaction consists of cash or stock in a non-public company.  Due to these contingent redemption provisions, the warrants require liability classification in accordance with ASC 480 and are recorded at fair value.   Holders of the June 2017 warrants contain a provision that allows the holder to opt for cash settlement in a fundamental transaction that was approved by, or required to be approved by, the board of directors of the Company. All of the Company’s outstanding warrants provide the holder the option as to the type of consideration received if the holders of common stock receive an option as to their consideration. In addition, all of the Company’s outstanding warrants contain a cashless exercise provision that is exercisable only in the event that a registration statement is not effective. That provision may not be operative if an effective registration statement is not available because an exemption under the U.S. securities laws may not be available to issue unregistered shares.  As a result, net cash settlement may be required, and the warrants require liability classification.

ASC 820 provides requirements for disclosure of liabilities that are measured at fair value on a recurring basis in periods subsequent to the initial recognition.  Fair values for warrants were determined using the Binomial Lattice (“Lattice”) valuation technique. The Lattice model provides for dynamic assumptions regarding volatility and risk-free interest rates within the total period to maturity. Accordingly, within the contractual term, the Company provided multiple date intervals over which multiple volatilities and risk free interest rates were used. These intervals allow the Lattice model to project outcomes along specific paths that consider volatilities and risk free rates that would be more likely in an early exercise scenario.

16

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

Significant assumptions are determined as follows:

Trading market values—Published trading market values;

Exercise price—Stated exercise price;

Term—Remaining contractual term of the warrant;

Volatility—Historical trading volatility for periods consistent with the remaining terms; and

Risk-free rate—Yields on zero coupon government securities with remaining terms consistent with the remaining terms of the warrants.

Due to the fundamental transaction provision, which could provide for early redemption of the warrants, the model also considered the probability the Company would enter into a fundamental transaction during the remaining term of the warrant. Because the Company is not yet achieving positive cash flow, management believes the probability of a fundamental transaction occurring over the term of the warrant is unlikely and therefore estimates the probability of entering into a fundamental transaction to be 5%.  For valuation purposes, the Company also assumed that if such a transaction did occur, it was more likely to occur towards the end of the term of the warrants.

The significant unobservable inputs used in the fair value measurement of the warrants include management’s estimate of the probability that a fundamental transaction may occur in the future.  Significant increases (decreases) in the probability of occurrence would result in a significantly higher (lower) fair value measurement.

The following table summarizes the fair value of the warrants as of the respective balance sheet dates:

	Fair Value as of:
Warrant Issuance:	June 30, 2017		December 31, 2016
December 2012 Investor Warrants	$	7,316	$	49
July 2013 Investor Warrants		183,108		2,060
October 2013 Investor Warrants		241,999		3,708
January 2014 Investor Warrants		303,762		714
November 2015 Investor Warrants		2,362,538		260,500
November 2015 Placement Agent Warrants		5,573		13,542
March 2016 Investor Warrants		1,219,172		358,945
March 2016 Placement Agent Warrants		-		21,320
September 2016 Investor Warrants		1,795,810		854,640
September 2016 Placement Agent Warrants		-		57,888
June 2017 Investor Warrants		3,289,759		-
June 2017 Placement Agent Warrants		387,554		-
Total:	$	9,796,591	$	1,573,366

17

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

The following table summarizes the number of shares indexed to the warrants as of the respective balance sheet dates:

	Number of Shares indexed as of:
Warrant Issuance	June 30, 2017		December 31, 2016
December 2012 Investor Warrants		17,430		17,430
July 2013 Investor Warrants		200,000		200,000
October 2013 Investor Warrants		231,732		231,732
January 2014 Investor Warrants		476,193		476,193
November 2015 Investor Warrants		1,250,001		1,250,001
November 2015 Placement Agent Warrants		3,334		83,335
March 2016 Investor Warrants		607,806		1,171,875
March 2016 Placement Agent Warrants		-		78,125
September 2016 Investor Warrants		805,000		1,800,000
September 2016 Placement Agent Warrants		-		144,000
June 2017 Investor Warrants		1,515,152		-
June 2017 Placement Agent Warrants		181,818		-
Total:		5,288,466		5,452,691

The assumptions used in calculating the fair values of the warrants are as follows:

	June 30, 2017			December 31, 2016
Trading market prices	$	2.86		$	1.40
Estimated future volatility		104	%		104	%
Dividend		-			-
Estimated future risk-free rate		1.23-2.31	%		1.06-2.44	%
Equivalent volatility		106-129	%		51-60	%
Equivalent risk-free rate		0.87-1.48	%		0.59-1.25	%

18

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

Changes in the fair value of the warrant liabilities, carried at fair value, reported as “unrealized gain (loss) on fair value of warrants” in the statement of operations:

	For the Three Months Ended  June 30,					For the Six Months Ended June 30,
	2017			2016		2017			2016
Expired Warrants	$	-		$	771	$	-		$	2,590
December 2012 Investor Warrants		35,454			5,911		(7,267	)		7,278
July 2013 Investor Warrants		368,332			63,246		(181,048	)		93,900
October 2013 Investor Warrants		438,919			103,166		(238,291	)		129,607
January 2014 Investor Warrants		778,762			92,428		(303,048	)		117,714
November 2015 Investor Warrants		2,017,712			875,913		(2,102,038	)		1,204,626
November 2015 Placement Agent Warrants		(96,560	)		58,276		(368,385	)		80,160
March 2016 Investor Warrants		702,730			860,121		(3,229,781	)		1,252,266
March 2016 Placement Agent Warrants		(82,867	)		58,258		(351,899	)		85,904
September 2016 Investor Warrants		928,592			-		(5,313,599	)		-
September 2016 Placement Agent Warrants		-			-		(503,150	)		-
June 2017 Investor Warrants		383,409			-		383,409			-
June 2017 Placement Agent Warrants		46,766			-		46,766			-
Total:	$	5,521,249		$	2,118,090	$	(12,168,331	)	$	2,974,045

19

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

13. Income Taxes

No provision for federal and state income taxes was required for the three and six months ended June 30, 2017 and 2016 due to the Company’s operating losses and increased deferred tax asset valuation allowance.  At June 30, 2017 and December 31, 2016, the Company had unused net operating loss carry-forwards of approximately $119,618,000 and $111,605,000 respectively, which expire at various dates through 2037.  Some of this amount may be subject to annual limitations under certain provisions of the Internal Revenue Code related to “changes in ownership.”

As of June 30, 2017 and December 31, 2016, the deferred tax assets related to the aforementioned carry-forwards have been fully offset by valuation allowances, because significant utilization of such amounts is not presently expected in the foreseeable future.

Deferred tax assets and valuation allowances consist of:

	June 30, 2017			December 31, 2016
Net Operating Loss Carryforwards	$	46,651,000		$	43,526,000
Stock Compensation Expense		2,109,000			1,968,000
Book tax differences on assets and liabilities		410,000			547,000
Valuation Allowance		(49,170,000	)		(46,041,000	)
Net Deferred Tax Assets	$	-		$	-

The Company files income tax returns in the U.S. federal and Maryland state jurisdictions.  Tax years for fiscal 2013 through 2016 are open and potentially subject to examination by the federal and Maryland state taxing authorities.

20

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

14. Commitments and Contingencies

a) The Company has contracted with various vendors for research and development services, with terms that require payments over the terms of the agreements, usually ranging from two to 36 months. The costs to be incurred are estimated and are subject to revision. As of June 30, 2017, the total estimated cost to complete these agreements was approximately $8,500,000.  All of these agreements may be terminated by either party upon appropriate notice as stipulated in the respective agreements.

b) On June 22, 2009, the Company entered into a License Agreement with Korea Research Institute of Chemical Technology (“KRICT”) to acquire the rights to all intellectual property related to quinoxaline-piperazine derivatives that were synthesized under a Joint Research Agreement.  The initial license fee was $100,000, all of which was paid as of December 31, 2009.  The agreement with KRICT calls for a one-time milestone payment of $1,000,000 within 30 days after the first achievement of marketing approval of the first commercial product arising out of or in connection with the use of KRICT’s intellectual property.  As of June 30, 2017, the milestone has not occurred.

c) Office Space Lease

On June 5, 2009, the Company entered into a commercial lease agreement for 5,466 square feet of office space in Rockville, Maryland.  The lease was amended on June 7, 2013 to extend the term until June 30, 2019.

On July 26, 2014 the lease was amended to add 1,727 square feet of office space for a term beginning on September 1, 2014 and ending on August 31, 2015, which was subsequently renewed for additional one-year terms, beginning on September 1, 2015 and 2016, and a 22-month term beginning September 1, 2017 and expiring on June 30, 2019. Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges.

Rent paid under the Company’s lease during the three months ended June 30, 2017 and 2016 was $50,898 and $51,301, respectively, and rent paid during the six months ended June 30, 2017 and 2016 was $101,796 and $102,603, respectively.

Laboratory Lease

On April 20, 2015, the Company signed a five-year lease agreement for 2,552 square feet of laboratory space commencing on July 1, 2015 and ending on June 30, 2020.  Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges. Rent paid under this lease during the three months ended June 30, 2017 and 2016 was $15,771 and $15,312, respectively, and rent paid during the six months ended June 30, 2017 was $31,543 and $30,624.

21

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

Future rental payments over the next five years for all leases are as follows:

For the remaining six months ending December 31:	2017	$	137,360
For the year ending December 31:	2018		279,274
	2019		176,080
	2020		34,468
	Total	$	627,182

d) The Company has established a 401(k) plan for its employees.  The Company has elected to match 100% of the first 3% of an employee’s compensation plus 50% of an additional 2% of the employee’s deferral. Expense related to this matching contribution aggregated to $34,606 and $31,587 for the three months ended June 30, 2017 and 2016, respectively, and $71,083 and $63,089 for the six months ended June 30, 2017 and 2016, respectively.

e) In July 2013, the Company entered into an exclusive license agreement with the University of Maryland, Baltimore for a novel drug delivery platform, Nano-Polymer Drug Conjugate Systems.  RX-21101 is the Company’s first drug candidate utilizing this platform.  The agreement requires the Company to make payments to the University of Maryland if RX-21101 or any products from the licensed delivery platform achieve development milestones.  As of June 30, 2017, no development milestones have occurred.

f) In October 2013, the Company signed an exclusive license agreement with the Ohio State Innovation Foundation, for a novel oligonucleotide drug delivery platform, Lipid-Coated Albumin Nanoparticle.  The agreement requires the Company to make payments to the Ohio State Innovation Foundation if any products from the licensed delivery platform achieve development milestones.  As of June 30, 2017, no development milestones have occurred.

22

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

15. Fair Value Measurements

ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, not adjusted for transaction costs.  ASC 820 also establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels giving the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3).

The three levels are described below:

Level 1 Inputs	—	Unadjusted quoted prices in active markets for identical assets or liabilities that are accessible by the Company;
Level 2 Inputs	—	Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly; and
Level 3 Inputs	—	Unobservable inputs for the asset or liability including significant assumptions of the Company and other market participants.

The following tables present assets and liabilities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy.  There have been no changes in the methodologies used at June 30, 2017 and December 31, 2016.

	Fair Value Measurements at June 30, 2017
	Total		Level 1		Level 2		Level 3
Assets:
Commercial Paper		3,215,330		-		3,215,330		-
Corporate Bonds		14,770,830		-		14,770,830		-
Total Assets:	$	17,986,160	$	-	$	17,986,160	$	-
Liabilities:
Warrant Liabilities	$	9,796,591	$	-	$	-	$	9,796,591

	Fair Value Measurements at December 31, 2016
	Total		Level 1		Level 2		Level 3
Assets:
Certificates of Deposit	$	720,197	$	-	$	720,197	$	-
Commercial Paper		3,985,740		-		3,985,740		-
Corporate Bonds		4,031,170		-		4,031,170		-
Total Assets:	$	8,737,107	$	-	$	8,737,107	$	-
Liabilities:
Warrant Liabilities	$	1,573,366	$	-	$	-	$	1,573,366

23

REXAHN PHARMACEUTICALS, INC.

Notes to Condensed Financial Statements

(Unaudited)

The fair value of the Company’s Level 2 marketable securities is determined by using quoted prices from independent pricing services that use market data for comparable securities in active or inactive markets.  A variety of data inputs, including benchmark yields, interest rates, known historical trades and broker dealer quotes are used with pricing models to determine the quoted prices.

The fair value methodology for the warrant liabilities is disclosed in Note 12.

The carrying amounts reported in the financial statements for cash and cash equivalents (Level 1), approximate fair value because of the short term maturity of these financial instruments.

The following table sets forth a reconciliation of changes for the six months ended June 30, 2017 and 2016 in the fair value of the liabilities classified as Level 3 in the fair value hierarchy:

	Warrant Liabilities
Balance at January 1, 2017	$	1,573,366
Additions		4,107,488
Unrealized losses, net		12,168,331
Transfers out of level 3		(8,052,594	)
Balance at June 30, 2017	$	9,796,591

	Warrant Liabilities
Balance at January 1, 2016	$	2,739,163
Additions		2,575,860
Unrealized gains, net		(2,974,045	)
Transfers out of level 3		-
Balance at June 30, 2016	$	2,340,978

Additions consist of the fair value of warrant liabilities upon issuance.  Transfers out of Level 3 for warrant liabilities consist of warrant exercises, where the liability is converted to additional paid-in capital upon exercise.  The Company’s policy is to recognize transfers in and transfers out as of the actual date of the event or change in circumstance that caused the transfer.

24

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

OVERVIEW

The following discussion should be read in conjunction with the unaudited condensed financial statements and notes thereto set forth in Item 1 of this Quarterly Report on Form 10-Q and the audited financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2016.

Except for the historical information contained herein, the matters discussed in this Quarterly Report on Form 10-Q may be deemed to be forward-looking statements that involve risks and uncertainties.  We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws.  In this Quarterly Report on Form 10-Q, words such as “believe”, “estimate”, “expect”, “anticipate”, “will”, “may”, “intend” and other similar expressions, are intended to identify forward-looking statements.  We caution that forward-looking statements are based largely on our expectations and are subject to a number of known and unknown risks and uncertainties that are subject to change based on factors that are, in many instances, beyond our control.  Actual results, performance or achievements may differ materially from those contemplated, expressed or implied by the forward-looking statements.

Although we believe that the expectations reflected in our forward-looking statements are reasonable as of the date we make them, actual results could differ materially from those currently anticipated due to a number of factors, including risks relating to:

· our understandings and beliefs regarding the role of certain biological mechanisms and processes in cancer;

· our drug candidates being in early stages of development, including in pre-clinical development;

· our ability to initially develop drug candidates for orphan indications to reduce the time-to-market and take advantage of certain incentives provided by the U.S. Food and Drug Administration;

· our ability to transition from our initial focus on developing drug candidates for orphan indications to candidates for more highly prevalent indications;

· our ability to successfully and timely complete clinical trials for our drug candidates in clinical development;

· uncertainties related to the timing, results and analyses related to our drug candidates in pre-clinical development;

· our ability to obtain the necessary U.S. and international regulatory approvals for our drug candidates;

· our reliance on third-party contract research organizations and other investigators and collaborators for certain research and development services;

· our ability to maintain or engage third-party manufacturers to manufacture, supply, store and distribute supplies of our drug candidates for our clinical trials;

25

· our ability to form strategic alliances and partnerships with pharmaceutical companies and other partners for sales and marketing of certain of our product candidates;

· demand for and market acceptance of our drug candidates;

· the scope and validity of our intellectual property protection for our drug candidates and our ability to develop our candidates without infringing the intellectual property rights of others;

· our lack of profitability and the need for additional capital to operate our business; and

· other risks and uncertainties, including those set forth herein and in our Annual Report on Form 10-K for the year ended December 31, 2016 under the caption “Risk Factors” and those detailed from time to time in our filings with the Securities and Exchange Commission.

These forward-looking statements are made only as of the date hereof, and we undertake no obligation to update or revise the forward-looking statements, whether as a result of new information, future events or otherwise.

We are a clinical stage biopharmaceutical company dedicated to the discovery, development and commercialization of innovative treatments for cancer. Our mission is to improve the lives of cancer patients by developing next-generation cancer therapies that are designed to maximize efficacy while minimizing the toxicity and side effects traditionally associated with cancer treatment. Our clinical pipeline features three oncology product candidates in Phase II clinical development and additional compounds in pre-clinical development. Our strategy is to continue building a significant pipeline of innovative oncology product candidates that we intend to commercialize with partners. Our three clinical stage drug candidates in active development are RX-3117, Supinoxin^TM (RX-5902) and Archexin®.

· RX-3117 is a small molecule nucleoside compound that we believe has therapeutic potential in a broad range of cancers, including pancreatic, bladder, colon, and lung cancer. RX-3117 is initially being evaluated as monotherapy in a multi-center Phase IIa clinical trial in metastatic pancreatic cancer in patients who are refractory to, or have relapsed after, multiple prior rounds of chemotherapy.  We are also planning to evaluate RX-3117 in combination with Abraxane® (nab-paclitaxel) as first line treatment in patients who are newly-diagnosed with metastatic pancreatic cancer and have not had prior cytotoxic treatment.  In 2016, we also commenced enrollment in a Phase IIa trial in patients with locally advanced or metastatic bladder cancer.  This Phase IIa clinical trial is a multi-center open label, single agent study of RX-3117 being conducted at 12 clinical centers in the United States.  RX-3117 has received orphan drug designation from the U.S. Food and Drug Administration (the “FDA”) for pancreatic cancer.  Orphan drug designation provides tax incentives for clinical research and a waiver from user fees under certain circumstances. In addition, an orphan drug generally receives seven years of exclusivity after approval for a designated use, during which period the FDA generally cannot approve another product with the same active moiety for the same indication.

· Supinoxin, or RX-5902, is a potential first-in-class small molecule inhibitor of phosphorylated-p68, a protein that we believe plays a key role in cancer cell growth, progression and metastasis through its interaction with beta-catenin. In February, 2017 we initiated a Phase IIa clinical study of Supinoxin in patients with metastatic triple negative breast cancer (“TNBC”).

26

· Archexin is a potential best-in-class, potent inhibitor of the protein kinase Akt-1, which we believe plays a critical role in cancer cell proliferation, survival, angiogenesis, metastasis and drug resistance. Archexin has received orphan drug designation from the FDA for renal cell carcinoma (“RCC”), glioblastoma, ovarian cancer, stomach cancer and pancreatic cancer. We are currently conducting a Phase IIa proof-of-concept clinical trial of Archexin in patients with metastatic renal cell carcinoma to evaluate its safety and efficacy in combination with AFINITOR® (everolimus).

Since our inception, our efforts and resources have been focused primarily on developing our pharmaceutical technologies, raising capital and recruiting personnel.  We have no product sales to date, and we will not generate any product sales until we receive approval from the FDA or equivalent foreign regulatory bodies to begin selling our pharmaceutical candidates.  Our major sources of working capital have been proceeds from various private and public financings, and licensing and collaboration agreements with our strategic investors and partners.

On May 5, 2017 the Company effected a one-for-ten reverse stock split of the outstanding shares of the Company’s common stock, together with a corresponding proportional reduction in the number of authorized shares of the Company’s capital stock.  See Note 10, “Common Stock—Reverse Stock Split,” in the Notes to Consolidated Financial Statements.

Recently Issued Accounting Standards

See Note 2, “Recent Accounting Pronouncements Affecting the Company,” in the Notes to Condensed Financial Statements for a discussion of recent accounting pronouncements.

Results of Operations

Comparison of the Three and Six Months Ended June 30, 2017 and June 30, 2016

Total Revenues

We had no revenues for the three and six months ended June 30, 2017 or 2016.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and related expenses for executive, finance and other administrative personnel, recruitment expenses, professional fees and other corporate expenses, including business development, investor relations, and general legal activities.

General and administrative expenses increased approximately $64,000, or 3.8%, to $1,740,000 for the three months ended June 30, 2017 from $1,676,000 for the three months ended June 30, 2016.  General and administrative expenses increased approximately $360,000, or 11.7%, to $3,431,000 for the six months ended June 30, 2017 from $3,071,000 for the six months ended June 30, 2016.  The increases were primarily attributable to higher personnel costs in 2017.

Research and Development Expenses

Research and development expenses increased approximately $307,000, or 13.7%, to $2,544,000 for the three months ended June 30, 2017, from $2,237,000 for the three months ended June 30, 2016.  Increased research and development costs for the three months ended June 30, 2017 were primarily due to increased clinical trial and patient enrollment costs for RX-3117.  Research and development expenses decreased approximately $899,000, or 15.8%, to $4,807,000 for the six months ended June 30, 2017, from $5,706,000 for the six months ended June 30, 2016.  Decreased research and development costs for the six months ended June 30, 2017, were primarily attributable to lower manufacturing costs for our drug candidates due to a significant supply of our drug candidates already being available to us from earlier manufacturing campaigns.  During the six months ended June 30, 2017, we incurred approximately $632,000 of drug manufacturing costs, compared to approximately $1,967,000 during the six months ended June 30, 2016.  Because the volume and timing of drug manufacturing does not correlate directly with the level and timing of clinical trial activity, we expect expenses related to drug manufacturing costs to vary from period to period based not only on the progress of clinical trials, but also when we engage in manufacturing activities.  The decreases to drug manufacturing costs were partially offset by the increases in clinical costs discussed above.  We expect research and development expenses to increase in the remaining quarters of 2017 compared to the quarter ended June 30, 2017 due to continued patient enrollment in our clinical trials and new manufacturing campaigns.

27

The table below summarizes the approximate amounts incurred in each of our research and development projects for the three and six months ended June 30, 2017 and 2016:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2017		2016		2017		2016
Clinical Candidates:
RX-3117	$	1,137,200	$	487,500	$	1,888,500	$	1,434,700
Supinoxin		286,700		593,300		697,800		1,329,400
Archexin		130,700		226,000		298,800		1,083,600
Preclinical, Personnel and Overhead		989,662		930,233		1,921,557		1,857,907
Total Research and Development Expenses	$	2,544,262	$	2,237,033	$	4,806,657	$	5,705,607

Interest Income

Interest income increased approximately $14,000 and $17,000 or 48.2% and 29.2%, respectively for the three and six months ended June 30, 2017, respectively, compared to the same periods in 2016.  The increases were primarily attributable to higher aggregate balances of cash and cash equivalents and marketable securities and higher interest rates on marketable securities for the three and six months ended June 30, 2017 compared to the same periods in 2016.

Unrealized Gain (Loss) on Fair Value of Warrants

Our warrants are recorded as liabilities at fair value, and the warrants are valued using a lattice model.  Changes in the fair value of warrants are recorded as an unrealized gain or loss in our statement of operations.  During the three months ended June 30, 2017 and 2016, we recorded unrealized gains  on the fair value of our warrants of approximately $5,521,000 and $2,118,000.  During the six months ended June 30, 2017, we recorded unrealized gains (losses) on the fair value of warrants of ($12,168,000) and $2,974,000 respectively.  Estimating fair values of warrants requires the development of significant and subjective estimates that may, and are likely to, change over the duration of the warrants due to related changes to external market factors.  The large unrealized gain for the three months ended June 30, 2017 primarily resulted from a significant decrease in the stock price of the underlying common stock at June 30, 2017 compared to March 31, 2017.  The large unrealized loss for the six months ended June 30, 2017 primarily resulted from a significant increase in the stock price of the underlying common stock at June 30, 2017 compared to December 31, 2016.  An increase in volatility of the common stock during that period and the large number of outstanding warrants also had an impact on the large unrealized loss for the six months ended June 30, 2017.

28

Financing Expense

We incurred approximately $333,000 of financing expenses during the three and six months ended June 30, 2017, related to our registered direct offering in June 2017.  We incurred approximately $170,000 of financing expenses during the six months ended June 30, 2016, related to our registered direct offering in March 2016.  We did not incur financing expenses during the three months ended June 30, 2016.

Net Income (Loss)

As a result of the above, net income (loss) for the three and six months ended June 30, 2017 was approximately $947,000 and ($20,664,000), or $0.04 and ($0.83) per basic share, respectively, compared to approximately ($1,766,000) and ($5,915,000), or ($0.08) and ($0.28) per share, respectively, for the three and six months ended June 30, 2016.  As previously discussed, included in the net income (loss) for the three and six months ended June 30, 2017 are non-cash charges of approximately $5,521,000 and ($12,168,000) in unrealized gains (losses) on the fair value of warrants, compared to unrealized gains of $2,118,000 and $2,974,000 for the three and six months ended June 30, 2016.

Research and Development Projects

Research and development costs are expensed as incurred.  These costs consist primarily of salaries and related personnel costs, costs to acquire pharmaceutical products and product rights for development and amounts paid to contract research organizations, hospitals and laboratories for the provision of services and materials for drug development and clinical trials.  Costs incurred in obtaining the license rights to technology in the research and development stage that have no alternative future uses are expensed as incurred.  Our research and development programs are related to our oncology clinical stage drug candidates, RX-3117, Supinoxin and Archexin, and our pre-clinical stage drug candidate, RX-21101.  As we expand our clinical studies, we expect to enter into additional development agreements.  Significant additional expenditures will be required if we complete our clinical trials, start new trials, apply for regulatory approvals, continue development of our technologies, expand our operations and bring our products to market.  The eventual total cost of each clinical trial is dependent on a number of uncertainties such as trial design, the length of the trial, the number of clinical sites and the number of patients.  The process of obtaining and maintaining regulatory approvals for new therapeutic products is lengthy, expensive and uncertain.  Because the successful development of our most advanced drug candidates, RX-3117, Supinoxin and Archexin, is uncertain, and because RX-21101 is in early-stage development, we are unable to estimate the costs of completing our research and development programs, the timing of bringing such programs to market and, therefore, when material cash inflows could commence from the sale of these drug candidates, if any.  If these projects are not completed as planned, our results of operations and financial condition would be negatively affected.

RX-3117

RX-3117 is a novel, investigational oral small molecule nucleoside compound.  We believe RX-3117 has therapeutic potential in a broad range of cancers including pancreatic, bladder, cervical, non-small cell lung cancer and colon cancer.  We previously identified the MTD of RX-3117, which we are evaluating in Phase IIa proof-of-concept clinical trials in patients with relapsed or refractory metastatic pancreatic cancer and patients with locally advanced or metastatic bladder cancer.

29

Expenses related to RX-3117 increased during the three and six months ended June 30, 2017 compared to the same period in 2016 due to increased clinical trial costs and increased patient enrollments resulting from the progression of our pancreatic and bladder cancer clinical trials. We expect that expenses related to RX-3117 will increase in the remainder of 2017 compared to the three and six months ended June 30, 2017 due to patient enrollment costs, new manufacturing campaigns, and the commencement of a combination Phase IIa clinical trial with Abraxane in pancreatic cancer.

Supinoxin (RX-5902)

Supinoxin is a potential first-in-class small molecule inhibitor of phosphorylated p68, a protein that we believe plays a key role in cancer growth, progression and metastasis through its interaction with beta-catenin. Phosphorylated p68 results in up-regulation of cancer-related genes and a subsequent proliferation of cancer cells and tumor growth.  In February 2017, we initiated a Phase IIa clinical study of Supinoxin in patients with metastatic TNBC.

Expenses related to Supinoxin decreased during the three and six months ended June 30, 2017 compared to the three and six months ended June 30, 2016.  The decrease is primarily attributable to decreased manufacturing costs due to a significant supply of drug product already available from earlier manufacturing campaigns.  However, we expect that expenses related to Supinoxin will increase in the remainder of 2017 compared to the three and six months ended June 30, 2017 due to patient enrollment costs associated with our Phase IIa trial in patients with metastatic TNBC and new manufacturing campaigns.

Archexin

Archexin is a potential best-in-class, potent inhibitor of the protein kinase Akt-1, which we believe plays a critical role in cancer cell proliferation, survival, angiogenesis, metastasis and drug resistance.  We are currently conducting a Phase IIa proof-of-concept clinical trial of Archexin in patients with metastatic RCC to evaluate its safety and efficacy in combination with AFINITOR (everolimus).

Expenses related to Archexin decreased during the three and six months ended June 30, 2017 compared to the same periods in 2016.  The decrease is primarily attributable to decreased manufacturing costs due to a significant supply of drug product already available.  We expect that expenses related to Archexin will remain flat for the remainder of 2017 compared to the three and six months ended June 30, 2017 as we continue the ongoing Archexin clinical trial.

Pre-clinical Pipeline

Expenses related to our pre-clinical candidates decreased for the three and six months ended June 30, 2017 compared to the same periods in 2016 primarily as a result of the timing of costs incurred for ongoing preclinical development.  We expect that expenses related to our pre-clinical pipeline, including RX-21101, will increase slightly for the remainder of 2017 compared to the three and six months ended June 30, 2017 as we continue testing and development.

30

Research and Development Process

We have engaged third-party contract research organizations and other investigators and collaborators, such as universities and medical institutions, to conduct our pre-clinical studies, toxicology studies and clinical trials.  Engaging third-party contract research organizations is typical practice in our industry. However, relying on such organizations means that the clinical trials and other studies described above are being conducted at external locations and that the completion of these trials and studies is not within our direct control. Trials and studies may be delayed due to circumstances outside our control, and such delays may result in additional expenses for us.

Liquidity and CapitalResources

Cash Flows

Cash used in operating activities was approximately $8,268,000 for the six months ended June 30, 2017.  The operating cash flows during the six months ended June 30, 2017 reflect a net loss of $20,664,000, offset by an unrealized loss on the fair value of warrants of $12,168,000 and a net increase of cash components of working capital and non-cash charges totaling $228,000.  Cash used in operating activities was approximately $8,612,000 for the six months ended June 30, 2016.  The operating cash flows during the six months ended June 30, 2016 reflect our net loss of $5,915,000, an unrealized gain on the fair value of warrants of 2,974,000 and a net increase of cash components of working capital and other non-cash charges totaling $277,000.

Cash used in investing activities was approximately $9,307,000 for the six months ended June 30, 2017, which consisted of $15,009,000 and $18,000 for the purchases of marketable securities and equipment, respectively, offset by $5,720,000 from the redemption of marketable securities. Cash provided by investing activities was approximately $1,711,000 for the six months ended June 30, 2016, which consisted of $3,440,000 from the redemption of marketable securities, offset by $1,722,000 and $7,000 for the purchases of marketable securities and equipment, respectively.

Cash provided by financing activities was approximately $14,787,000 for the six months ended June 30, 2017, which consisted of net proceeds of $9,355,000 from our registered direct public offering in June 2017 and $5,354,000 and $78,000 from the exercise of stock warrants and options, respectively.  Cash provided by financing activities was approximately $4,580,000 for the six months ended June 30, 2016, which consisted of net proceeds from our registered direct public offering in March 2016.

Contractual Obligations

We have a variety of contractual obligations, as more fully described in our 2016 Form 10-K.  These obligations include, but are not limited to, contractual obligations in connection with license agreements (including related milestone payments), lease payments, employee compensation and incentive program expenses, and contracts with various vendors for research and development services.  As of June 30, 2017, the total estimated cost to complete our contracts with vendors for research and development services was approximately $8,500,000 under the terms of the applicable agreements.  All of these agreements may be terminated by either party upon appropriate notice as stipulated in the respective agreements.

31

Current and Future Financing Needs

We have incurred negative cash flow from operations since we started our business.  We have spent, and expect to continue to spend, substantial amounts in connection with implementing our business strategy, including our planned product development efforts, our clinical trials and our research and development efforts.  We will need to raise additional capital through public or private equity or debt offerings or through arrangements with strategic partners or other sources in order to continue to develop our drug candidates.  There can be no assurance that additional capital will be available when needed or on terms satisfactory to us, if at all.  If we are not able to raise sufficient additional capital, we will have to reduce our research and development activities. We believe our cash, cash equivalents, and marketable securities will be sufficient to cover our cash flow requirements for our current activities for at least the next 12 months from the date these financial statements were issued.

The actual amount of funds we will need to operate is subject to many factors, some of which are beyond our control.  These factors include the following:

· the progress of our product development activities;

· the number and scope of our product development programs;

· the progress of our pre-clinical and clinical trial activities;

· the progress of the development efforts of parties with whom we have entered into collaboration agreements;

· our ability to maintain current collaboration programs and to establish new collaboration arrangements;

· the costs involved in prosecuting and enforcing patent claims and other intellectual property rights; and

· the costs and timing of regulatory approvals.

Off-Balance Sheet Arrangements

We do not have any off-balance sheet arrangements or holdings in variable interest entities.

32

Item 3. Quantitative and Qualitative Disclosures About Market Risk.

For quantitative and qualitative disclosures about market risk, refer to “Quantitative and Qualitative Disclosures About Market Risk” in our 2016 Form 10-K.  Our exposures to market risk have not changed materially since December 31, 2016.

Item 4. Controls and Procedures.

Disclosure Controls and Procedures

Under the supervision and with the participation of our management, including our Chief Executive Officer (“CEO”) and Chief Financial Officer (“CFO”), we evaluated the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) as of the end of the period covered by this report. Based upon that evaluation, our CEO and CFO concluded that our disclosure controls and procedures as of the end of the period covered by this report were effective such that the information required to be disclosed by us in reports filed under the Exchange Act is (i) recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s (the “SEC’s”) rules and forms and (ii) accumulated and communicated to our management, including our CEO and CFO, as appropriate to allow timely decisions regarding disclosure. A controls system cannot provide absolute assurance, however, that the objectives of the controls system are met, and no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, within a company have been detected.

Changes in Internal Control Over Financial Reporting

There has been no change in our internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the quarter ended June 30, 2017 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

33

PART II. Other Information

Item 1A. Risk Factors.

Investing in our stock involves a high degree of risk.  In addition to the other information set forth in this report, you should carefully consider the factors set forth in the Risk Factors section of our 2016 Form 10-K, as well as other information contained in the 2016 Form 10-K and in other reports we file with the SEC. We do not believe that there have been any material changes to the risk factors disclosed in our 2016 Form 10-K.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.

During the three months ended June 30, 2017, we issued 27,852 and 13,257 shares of common stock to warrant holders upon exercise of unregistered warrants that were issued pursuant to letter agreements, dated February 26, 2016, and November 5, 2015, respectively, between us and H.C. Wainwright and Company, LLC.  The warrants and the warrant shares were not registered under the Securities Act pursuant to the exemption from registration requirements provided by Section 4(a)(2) of the Securities Act, as transactions not involving a public offering.

Item 5. Other Information.

On August 2, 2017, we terminated the at market issuance sales agreement, dated as of March 16, 2015, with MLV & Co. LLC, now part of FBR & Co. (“MLV”) pursuant to which we were entitled to issue and sell shares of our common stock having an aggregate offering price of up to $40 million from time to time, at our option, through MLV as our sales agent.  Prior to termination of the agreement, due to limitations agreed to by us in connection with our prior registered direct offerings, we were not able to use the sale agreement until June 12, 2018.

Item 6. Exhibits.

The exhibits filed as part of this Quarterly Report on Form 10-Q are set forth on the Exhibit Index, which is incorporated herein by reference.

34

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

		REXAHN PHARMACEUTICALS, INC.
		(Registrant)
	By:	/s/ Peter D. Suzdak
Date: August 4, 2017		Peter D. Suzdak
		Chief Executive Officer (principal executive officer)
	By:	/s/ Tae Heum Jeong
Date: August 4, 2017		Tae Heum Jeong
		Chief Financial Officer and Secretary (principal financial and accounting officer)

35

EXHIBIT INDEX

Exhibit No.	Description
3.1	Certificate of Amendment of Amended and Restated Certificate of Incorporation of Rexahn Pharmaceuticals, Inc., filed as exhibit 3.1 to the Company’s Current Report on Form 8-K filed May 5, 2017, is incorporated herein by reference.
4.1	Form of Warrant, filed as Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on June 7, 2017, is incorporated herein by reference.
10.1	Form of Securities Purchase Agreement, dated as of June 6, 2017, by and between Rexahn Pharmaceuticals, Inc. and the purchasers identified on the signature pages thereto, filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed on June 7, 2017, is incorporated herein by reference.
10.2	Fifth Amendment to Lease Agreement, dated April 13, 2017, by and between Rexahn Pharmaceuticals, Inc. and SG Plaza Holdings, LLC.
31.1	Certification of Chief Executive Officer pursuant to Rules 13a-14(a) / 15d-14(a)
31.2	Certification of Chief Financial Officer pursuant to Rules 13a-14(a) / 15d-14(a)
32.1	Certification of Chief Executive Officer pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
32.2	Certification of Chief Financial Officer pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
101	The following materials from Rexahn Pharmaceuticals, Inc.’s Quarterly Report on Form 10-Q, formatted in Extensible Business Reporting Language (“XBRL”): (i) Condensed Balance Sheet; (ii) Condensed Statement of Operations; (iii) Condensed Statement of Comprehensive Income (Loss); (iv) Condensed Statement of Cash Flows; and (v) Notes to the Financial Statements.

EX-10.2

Exhibit 10.2

FIFTH AMENDMENT TO LEASE

This Fifth Amendment to Lease (the “Fifth Amendment”) is made and entered into this 13^th day of April, 2017 (the “Effective Date”), by and between SG PLAZA HOLDINGS, LLC, a Delaware limited liability company ("Landlord"), and REXAHN PHARMACEUTICALS, INC., a Delaware corporation ("Client").

WHEREAS, The Realty Associates Fund V, L.P., as landlord (“Original Landlord”), and Client entered into a Standard Office Lease and Addendum thereto (“Addendum”), both dated June 5, 2009; and Landlord, as successor in interest to Original Landlord, and Client entered into a First Amendment to Lease dated June 7, 2013 (“First Amendment”), a Second Amendment to Lease dated July 26, 2014 (“Second Amendment”), a Third Amendment to Lease dated May 6, 2015 (“Third Amendment”), and a Fourth Amendment to Lease dated April 4, 2016 (“Fourth Amendment”) (collectively, the “Lease”), under which Client leases approximately seven thousand one hundred three (7,103) rentable square feet of space on the Fifth (4^th) floor of the Building (the “Premises”), comprised of Suite 455 (approximately 5,466 rentable square feet) and Suite 475 (approximately 1,637 rentable square feet), in the building located at 15245 Shady Grove Road, Rockville, Maryland 20850, and known as Shady Grove Plaza (the “Building”); and

WHEREAS, the Lease is scheduled to expire on June 30, 2019 with respect to Suite 455; and

WHEREAS, the Lease is scheduled to expire on August 31, 2017 with respect to Suite 475; and

WHEREAS, Suite 475 has been remeasured and contains 1,727 rentable square feet; and

WHEREAS, Landlord and Client wish, among other matters, to amend the Lease to further extend the term of the Lease with respect to Suite 475 and to correct the rentable square feet therein, all on the terms hereinafter contained.

NOW THEREFORE, in consideration of the foregoing, and other good and valuable consideration, the receipt and sufficiency of which is acknowledged by the parties, the parties agree as follows:

1.          Suite 475 Third Extension Term.  The “Suite 475 Third Extension Term” shall commence on September 1, 2017 (the “Suite 475 Third Extension Term Commencement Date”) and shall expire on June 30, 2019.

2.          Remeasurement of Suite 475.  As of the Suite 475 Third Extension Term Commencement Date, the rentable square feet in Suite 475 shall be 1,727 and the total rentable square feet in the Premises shall be 7,193.

3.          Base Rent Payable for Suite 475 during the Suite 475 Third Extension Term.  Effective as of the Suite 475 Third Extension Term Commencement Date, Client shall pay Landlord Base Rent for Suite 475 at an initial rate of Twenty-six and 00/100 Dollars ($26.00) per rentable square foot of space, in legal tender, at Landlord’s office, the annual sum of Forty-Four Thousand Nine Hundred Two and 00/100 Dollars ($44,902.00), payable in equal monthly installments of Three Thousand Seven Hundred Forty-one and 83/100 Dollars ($3,741.83), in advance, promptly on the first day of each calendar month, without notice or demand, the same being hereby waived, and without any setoff, deduction, or recoupment whatsoever.  Notwithstanding the foregoing, so long as Client is not in default under the Lease beyond any applicable notice and cure periods, Landlord shall abate the Base Rent otherwise payable for Suite 475 for each of the months of September 2017 and October 2017.  On September 1, 2018, the Base Rent payable for Suite 475 shall be increased to Twenty-six and 78/100 Dollars ($26.78) per rentable square foot of space, the annual sum of Forty-Six Thousand Two Hundred Forty-nine and 06/100 Dollars ($46,249.06), payable as aforesaid in equal monthly installments of Three Thousand Eight Hundred Fifty-four and 09/100 Dollars ($3,854.09).  The Base Rent payable under this Section 2 is for Suite 475 only and is in addition to the Base Rent payable for Suite 455.

4.          Operating Expenses and Real Property Taxes Payable for Premises during Suite 475 Third Extension Term.   During the Suite 475 Third Extension Term, Client shall continue to pay to Landlord Client’s Share of increased Operating Expenses and Client’s Share of increased Real Property Taxes for the Premises in accordance with the provisions of the Lease, except that Client’s Share shall mean 3.93%.

5.          Condition of Premises.  Client agrees to accept the Premises in its then “as is" condition as of the Suite 475 Third Extension Term Commencement Date.

6.          Brokerage.  Client warrants that it has had no dealings with any broker or agent other than CBRE, Inc., Client’s agent, and Scheer Partners, Landlord’s agent, in connection with the negotiation or execution of this Fifth Amendment, and Client agrees to indemnify Landlord against all costs, expenses, attorneys' fees or other liability for commissions or other compensation or charges claimed by any other broker or agent claiming the same by, through or under Client.

7.          Option to Renew.   Client’s option to renew the term of the Lease for an additional five (5) years in accordance with the provisions of Section 4 of the Addendum shall apply to the entire Premises (i.e., if Client exercises such option, it must do so with respect to the entire Premises).

8.          Defined Terms.  Except as otherwise expressly provided herein, all defined terms shall have the same meanings as provided in the Lease.

9.          Headings.  Headings contained in this Fifth Amendment are for convenience only and are not substantive to the provisions of this Fifth Amendment.

10.        Lease Terms Ratified.  Except as otherwise expressly provided herein, and unless inconsistent with the terms hereof, all other terms, conditions and covenants of the Lease are hereby ratified and confirmed, and shall apply to the Premises during the Suite 475 Third Extension Term.  Client certifies to Landlord that the Lease is in full force and effect, that Landlord is not in default or breach of any of Landlord's obligations under the Lease, and that Client is unaware of any condition or circumstance which, but for the passage of time or delivery of notice, would constitute a default by Landlord under the Lease.

- 2 -

IN WITNESS WHEREOF, the parties have executed this Fifth Amendment by affixing their hands and seals as of the date noted above.

	Client:
WITNESS/ATTEST:	REXAHN PHARMACEUTICALS, INC., a Delaware corporation
/s/ Tae Heum Jeong	By: /s/ Peter Suzdak     [SEAL]
	Name: Peter Suzdak
	Title: CEO
	Landlord:
WITNESS/ATTEST:	SG PLAZA HOLDINGS, LLC, a Delaware limited liability company
/s/ Natalia Maselli	By: /s/ Andrew Nathan
	Andrew Nathan, CEO

- 3 -

EX-31.1

Exhibit 31.1

CERTIFICATION PURSUANT TO RULES 13A-14(D)

AND 15D-14(D)

I, Peter D. Suzdak, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Rexahn Pharmaceuticals, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c. Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d. Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Dated:  August 4, 2017

/s/ Peter D. Suzdak

Peter D. Suzdak

Chief Executive Officer

EX-31.2

Exhibit 31.2

CERTIFICATION PURSUANT TO RULES 13A-14(D)

AND 15D-14(D)

I, Tae Heum Jeong, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Rexahn Pharmaceuticals, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c. Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d. Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Dated:  August 4, 2017

/s/ Tae Heum Jeong

Tae Heum Jeong

Chief Financial Officer

EX-32.1

Exhibit 32.1

CERTIFICATION OF

CHIEF EXECUTIVE OFFICER

PURSUANT TO

18 U.S.C. SECTION 1350

SECTION 1350 CERTIFICATION*

In connection with the Quarterly Report of Rexahn Pharmaceuticals, Inc. (the “Company”) on Form 10-Q for the quarter ended June 30, 2017 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Peter D. Suzdak, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: August 4, 2017	By:	/s/ Peter D. Suzdak
		Peter D. Suzdak,
		Chief Executive Officer

* This Certification is being furnished as required by Rule 13a-14(b) under the Securities Exchange Act of 1934 (the “Exchange Act”) and Section 1350 of Chapter 63 of Title 18 of the United States Code, and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liability of that section. This Certification shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Exchange Act, except as otherwise stated in such filing.

A signed original of this written statement required by 18 U.S.C. § 1350 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

 

EX-32.2

Exhibit 32.2

CERTIFICATION OF

CHIEF FINANCIAL OFFICER

PURSUANT TO

18 U.S.C. SECTION 1350

SECTION 1350 CERTIFICATION*

In connection with the Quarterly Report of Rexahn Pharmaceuticals, Inc. (the “Company”) on Form 10-Q for the quarter ended June 30, 2017 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Tae Heum Jeong, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: August 4, 2017	By:	/s/ Tae Heum Jeong
		Tae Heum Jeong,
		Chief Financial Officer

* This Certification is being furnished as required by Rule 13a-14(b) under the Securities Exchange Act of 1934 (the “Exchange Act”) and Section 1350 of Chapter 63 of Title 18 of the United States Code, and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liability of that section. This Certification shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Exchange Act, except as otherwise stated in such filing.

A signed original of this written statement required by 18 U.S.C. § 1350 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

XML

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 04, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Entity Registrant Name	REXAHN PHARMACEUTICALS, INC.
Entity Central Index Key	0001228627
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Trading Symbol	rnn
Entity Common Stock, Shares Outstanding		28,459,805

XML

Condensed Balance Sheet - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 8,790,519	$ 11,578,473
Marketable securities	17,986,160	8,737,107
Prepaid expenses and other current assets	1,199,641	608,517
Total Current Assets	27,976,320	20,924,097
Security Deposits	30,785	30,785
Equipment, Net	86,610	88,650
Total Assets	28,093,715	21,043,532
Current Liabilities:
Accounts payable and accrued expenses	1,917,739	1,882,500
Deferred Research and Development Arrangement	412,500	450,000
Other Liabilities	65,812	79,204
Warrant Liabilities	9,796,591	1,573,366
Total Liabilities	12,192,642	3,985,070
Commitments and Contingencies (note 14)
Stockholders' Equity:
Preferred stock, par value $0.0001, 10,000,000 authorized shares, none issued and outstanding
Common stock, par value $0.0001, 50,000,000 authorized shares, 28,452,305 and 23,736,878 issued and outstanding	2,845	2,374
Additional paid-in capital	151,612,110	132,086,419
Accumulated other comprehensive loss	(25,705)	(6,122)
Accumulated deficit	(135,688,177)	(115,024,209)
Total Stockholders' Equity	15,901,073	17,058,462
Total Liabilities and Stockholders' Equity	$ 28,093,715	$ 21,043,532

XML

Condensed Balance Sheet (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Condensed Balance Sheet [Abstract]
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par Value	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	50,000,000	50,000,000
Common Stock, Shares, Issued	28,452,305	23,736,878
Common Stock, Shares, Outstanding	28,452,305	23,736,878

XML

Condensed Statement Of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Statement Of Operations [Abstract]
Revenues:
Expenses:
General and administrative	1,739,663	1,675,749	3,430,509	3,071,155
Research and development	2,544,262	2,237,033	4,806,657	5,705,607
Total Expenses	4,283,925	3,912,782	8,237,166	8,776,762
Loss from Operations	(4,283,925)	(3,912,782)	(8,237,166)	(8,776,762)
Other Income (Expense)
Interest income	42,782	28,868	74,579	57,738
Unrealized gain (loss) on fair value of warrants	5,521,249	2,118,090	(12,168,331)	2,974,045
Financing expense	(333,050)		(333,050)	(169,887)
Total Other Income (Expense)	5,230,981	2,146,958	(12,426,802)	2,861,896
Net Income (Loss) Before Provision for Income Taxes	947,056	(1,765,824)	(20,663,968)	(5,914,866)
Provision for income taxes
Net Income (Loss)	$ 947,056	$ (1,765,824)	$ (20,663,968)	$ (5,914,866)
Net income (loss) per share, basic	$ 0.04	$ (0.08)	$ (0.83)	$ (0.28)
Net income (loss) per share, diluted	$ 0.03	$ (0.08)	$ (0.83)	$ (0.28)
Weighted average number of shares outstanding, basic	26,001,797	21,318,433	24,932,705	20,788,557
Weighted average number of shares outstanding, diluted	28,265,440	21,318,433	24,932,705	20,788,557

XML

Condensed Statement Of Comprehensive Income (Loss) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Statement Of Comprehensive Income (Loss) [Abstract]
Net Income (Loss)	$ 947,056	$ (1,765,824)	$ (20,663,968)	$ (5,914,866)
Unrealized (loss) gain on available-for-sale securities	(19,379)	3,733	(19,583)	20,368
Comprehensive Income (Loss)	$ 927,677	$ (1,762,091)	$ (20,683,551)	$ (5,894,498)

XML

Condensed Statement Of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash Flows from Operating Activities:
Net loss	$ (20,663,968)	$ (5,914,866)
Adjustments to reconcile net loss to net cash used in operating activities:
Compensatory stock	12,750	64,949
Depreciation and amortization	19,950	15,053
Amortization of premiums and discounts on marketable securities, net	20,024	22,315
Stock-based compensation	562,392	694,187
Amortization of deferred research and development arrangements	(37,500)	(37,500)
Unrealized loss (gain) on fair value of warrants	12,168,331	(2,974,045)
Financing expense	333,050	169,887
Amortization of deferred lease incentive	(6,222)	(6,222)
Deferred lease expenses	(7,170)	(5,203)
Changes in assets and liabilities:
Prepaid expenses and other assets	(591,124)	225,735
Accounts payable and accrued expenses	(78,492)	(866,651)
Net Cash Used in Operating Activities	(8,267,979)	(8,612,361)
Cash Flows from Investing Activities:
Purchase of equipment	(17,910)	(7,511)
Purchase of marketable securities	(15,008,660)	(1,721,760)
Redemption of marketable securities	5,720,000	3,440,000
Net Cash (Used in) Provided by Investing Activities	(9,306,570)	1,710,729
Cash Flows from Financing Activities:
Issuance of common stock and units, net of issuance costs	9,355,002	4,580,187
Proceeds from exercise of stock warrants	5,354,093
Proceeds from exercise of stock options	77,500
Net Cash Provided by Financing Activities	14,786,595	4,580,187
Net Decrease in Cash and Cash Equivalents	(2,787,954)	(2,321,445)
Cash and Cash Equivalents - beginning of period	11,578,473	10,199,440
Cash and Cash Equivalents - end of period	8,790,519	7,877,995
Non-cash financing and investing activties:
Warrants issued	4,107,488	$ 2,575,860
Warrant liability extinguishment from exercise of warrants	8,052,594
Offering costs included in accounts payable and accrued expenses	$ 113,731

XML

Operations And Organization

6 Months Ended

Jun. 30, 2017

Operations And Organization [Abstract]

Operations And Organization

1.Operations and Organization

Operations

Rexahn Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, is a biopharmaceutical company whose principal operations are the discovery, development and commercialization of innovative treatments for cancer.  The Company had an accumulated deficit of $135,688,177 at June 30, 2017 and anticipates incurring losses through fiscal year 2017 and beyond.  The Company has not yet generated commercial revenues and has funded its operating losses to date through the sale of shares of its common stock and warrants to purchase shares of its common stock, convertible debt, interest income from cash, cash equivalents and marketable securities, and proceeds from reimbursed research and development costs.  The Company believes that its cash, cash equivalents, and marketable securities will be sufficient to cover its cash flow requirements for its current activities for at least the next 12 months from the date these financial statements were issued.  Management believes it has the capability of managing the Company’s operations within existing cash available by focusing on select research and development activities, selecting projects in conjunction with potential financings and milestones, and efficiently managing the Company’s general and administrative affairs.

Basis of Presentation

The accompanying unaudited condensed financial statements of the Company have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission for interim financial information.  Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete financial statements.  In the opinion of the Company’s management, all adjustments (consisting of only normal recurring accruals) considered necessary for a fair presentation of the Company’s financial position as of June 30, 2017 and December 31, 2016 and of the results of operations and comprehensive income (loss) for the three and six months ended June 30, 2017 and 2016 and cash flows for the six months ended June 30, 2017 and 2016 have been included.  Operating results for the three and six months ended June 30, 2017 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2017. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the “2016 Form 10-K”).  Information included in the condensed balance sheet as of December 31, 2016 has been derived from the Company’s audited financial statements for the year ended December 31, 2016 included in the 2016 Form 10-K.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future.  Actual results may ultimately differ from these estimates.  These estimates are reviewed periodically, and as adjustments become necessary, they are reported in earnings in the period in which they become available.

XML

Recent Accounting Pronouncements Affecting the Company

6 Months Ended

Jun. 30, 2017

Recent Accounting Pronouncements Affecting the Company [Abstract]

Recent Accounting Pronouncements Affecting the Company

2. Recent Accounting Pronouncements Affecting the Company

Revenue from Contracts with Customers

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company should recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services, and provides a revenue recognition framework in accordance with this principle.  On August 12, 2015, the FASB issued ASU 2015-14, which defers the effective date of ASU 2014-09 by one year to December 15, 2017 for annual reporting periods beginning after that date and interim periods therein.  Early adoption of the standard is permitted.  The Company is currently evaluating the impact that the adoption of this guidance will have on its financial statements and future operating results.

Leases

In February 2016, the FASB issued ASU 2016-02, “Leases,” which requires an entity to recognize assets and liabilities arising from leases on the balance sheet and to provide additional disclosures about leasing arrangements.  ASU 2016-02 will be effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.

Compensation-Stock Compensation

In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation: Improvements to Employee Share Based Payment Accounting,” which includes multiple provisions intended to simplify various aspects of accounting for share-based payments.  The guidance is effective for reporting periods beginning after December 15, 2016, with early adoption permitted.  The Company adopted this guidance for the three months ended March 31, 2017.  This pronouncement did not have a material impact on the financial statements.

XML

Marketable Securities

6 Months Ended

Jun. 30, 2017

Marketable Securities [Abstract]

Marketable Securities

3.  Marketable Securities

Marketable securities are considered “available-for-sale” in accordance with FASB Accounting Standards Codification (“ASC”) 320, “Debt and Equity Securities,” and thus are reported at fair value in the Company’s accompanying balance sheet, with unrealized gains and losses excluded from earnings and reported as a separate component of stockholders’ equity.  Amounts reclassified out of accumulated other comprehensive income (loss) into realized gains and losses are accounted for on the basis of specific identification and are included in other income or expense in the statement of operations.  The Company classifies such investments as current on the balance sheet as the investments are readily marketable and available for use in current operations.   

The following table shows the Company’s marketable securities’ adjusted cost, gross unrealized gains and losses, and fair value by significant investment category as of June 30, 2017 and December 31, 2016:

		June 30, 2017
		Cost		Gross Unrealized		Gross Unrealized		Fair
		Basis		Gains		Losses		Value
Commercial Paper	$	3,220,126	$	-	$	(4,796)	$	3,215,330
Corporate Bonds		14,791,739		-		(20,909)		14,770,830
Total Marketable Securities	$	18,011,865	$	-	$	(25,705)	$	17,986,160
		December 31, 2016
		Cost		Gross Unrealized		Gross Unrealized		Fair
		Basis		Gains		Losses		Value
Certificates of Deposit	$	720,000	$	197	$	-	$	720,197
Commercial Paper		3,987,424		-		(1,684)		3,985,740
Corporate Bonds		4,035,805		-		(4,635)		4,031,170
Total Marketable Securities	$	8,743,229	$	197	$	(6,319)	$	8,737,107

The Company typically invests in highly-rated securities, with the primary objective of minimizing the potential risk of principal loss.  As of June 30, 2017, the Company had three investments of commercial paper with an aggregate fair value of $3,215,330 and unrealized losses of $4,796, and 14 corporate bonds with an aggregate fair value of $13,770,830 and unrealized losses of $20,909, all of which have been unrealized losses for less than 12 months.  The Company does not intend to sell its marketable securities in an unrealized loss position.  Based upon these securities’ fair value relative to the cost, high ratings, and volatility of fair value, the Company considers the declines in market value of its marketable securities to be temporary in nature, does not consider any of its investments other-than-temporarily impaired, and anticipates that it will recover the entire amortized cost basis.

The amortized cost basis and fair value of marketable securities by contractual maturity are:

Maturity	Cost Basis		Fair Value
Less than 1 year	$	12,274,138	$	12,257,650
1 to 5 years		5,737,727		5,728,510
Total Marketable Securities	$	18,011,865	$	17,986,160

XML

Prepaid Expenses And Other Current Assets

6 Months Ended

Jun. 30, 2017

Prepaid Expenses And Other Current Assets [Abstract]

Prepaid Expenses And Other Current Assets

4.  Prepaid Expenses and Other Current Assets

	June 30,		December 31,
	2017		2016
Deposits on contracts	$	532,602	$	179,476
Prepaid expenses and other current assets		667,039		429,041
	$	1,199,641	$	608,517

Deposits on contracts consist of deposits on research and development contracts for services that had not been incurred as of the balance sheet date.  Prepaid expenses and other assets include prepaid general and administrative expenses, such as insurance, rent, investor relations fees and compensatory stock issued for services not yet incurred as of the balance sheet date.

XML

Equipment, Net

6 Months Ended

Jun. 30, 2017

Equipment, Net [Abstract]

Equipment, Net

5.  Equipment, Net

	June 30,		December 31,
	2017		2016
Furniture and fixtures	$	78,794	$	78,794
Office and computer equipment		118,358		113,932
Lab equipment		445,134		431,650
Leasehold improvements		133,762		133,762
Total equipment		776,048		758,138
Less: Accumulated depreciation and amortization		(689,438)		(669,488)
Net carrying amount	$	86,610	$	88,650

XML

Accounts Payable And Accrued Expenses

6 Months Ended

Jun. 30, 2017

Accounts Payable And Accrued Expenses [Abstract]

Accounts Payable And Accrued Expenses

6.  Accounts Payable and Accrued Expenses

	June 30,		December 31,
	2017		2016
Trade payables	$	509,085	$	430,013
Accrued expenses		167,297		141,190
Accrued research and development contract costs		715,065		499,889
Payroll liabilities		526,292		811,408
	$	1,917,739	$	1,882,500

XML

Deferred Research And Development Arrangements

6 Months Ended

Jun. 30, 2017

Deferred Research And Development Arrangements [Abstract]

Deferred Research And Development Arrangements

7.  Deferred Research and Development Arrangement

Rexgene Biotech Co., Ltd.

In 2003, the Company entered into a collaborative research agreement with Rexgene Biotech Co., Ltd. (“Rexgene”), a shareholder.  Rexgene is engaged in the development of pharmaceutical products in Asia and has agreed to assist the Company with the research, development and clinical trials necessary for registration of the Company’s drug candidate Archexin® in Asia.  This agreement provides Rexgene with exclusive rights to license, sublicense, make, have made, use, sell and import Archexin in Asia.  In accordance with the agreement, Rexgene paid the Company a one-time fee of $1,500,000 in 2003.  The agreement terminates at the later of 20 years or the term of the patent.  The amortization reduces research and development expenses for the periods presented. 

The Company is using 20 years as its basis for recognition and accordingly, research and development expenses were reduced by$18,750 and $37,500for the three and six months ended June 30, 2017 and 2016, respectively.  The remaining $412,500 and $450,000 to be amortized at June 30, 2017 and December 31, 2016, respectively, is reflected as a deferred research and development arrangement on the balance sheet.  The payment from Rexgene is being used in the cooperative funding of the costs of development of Archexin. Royalties of 3% of net sales of licensed products will become payable by Rexgene to the Company on a quarterly basis once commercial sales of Archexin begin in Asia.  The product is still under development and commercial sales in Asia are not expected to begin until at least 2018. 

XML

Other Liabilities

6 Months Ended

Jun. 30, 2017

Other Liabilities [Abstract]

Other Liabilities

8. Other Liabilities

Deferred Lease Incentive

In accordance with the Company’s office lease agreement, as amended and further discussed in Note 14, the Company has been granted leasehold improvement allowances from the lessor to be used for the construction cost of improvements to the leased property, which included architectural and engineering fees, government agency plan check, permit and other fees, sales and use taxes, testing and inspection costs and telephone and data cabling and wiring in the premises.  The Company accounted for the benefit of the leasehold improvement allowance as a reduction of rental expense over the term of the office lease.

The following table sets forth the cumulative deferred lease incentive:

	June 30,		December 31,
	2017		2016
Deferred lease incentive	$	154,660	$	154,660
Less accumulated amortization		(129,773)		(123,551)
Balance	$	24,887	$	31,109

Deferred Office Lease Expense

The lease agreement, as amended, provided for an initial annual base rent with annual increases over the lease term.  The Company recognizes rental expense on a straight-line basis over the term of the lease, which resulted in a deferred rent liability of $40,925 and $48,095 as of June 30, 2017 and December 31, 2016, respectively.

XML

Net Income (Loss) Per Common Share

6 Months Ended

Jun. 30, 2017

Net Income (Loss) Per Common Share [Abstract]

Net Income (Loss) Per Common Share

9.Net Income (Loss) per Common Share

Basic income (loss) per common share is computed by dividing net income (loss) by the weighted average number of shares of common stock outstanding for the period.  Diluted loss per common share is computed by dividing net loss by the weighted average number of shares of common stock outstanding, plus the number of common share equivalents that would be dilutive.  As of June 30, 2017 and December 31, 2016, there were stock options, restricted stock units and warrants to acquire, in the aggregate, 7,280,637 and 7,142,728 shares of the Company’s common stock, respectively, that are potentially dilutive. However, with the exception of the three months ended June 30, 2017, diluted loss per share is the same as basic loss per share for all periods presented because the inclusion of common share equivalents would be anti-dilutive.  For the three months ended June 30, 2017, the dilutive effect of stock warrants, stock options and restricted stock units is 1,177,987,  1,031,356 and 54,300, respectively.

XML

Common Stock

6 Months Ended

Jun. 30, 2017

Common Stock [Abstract]

Common Stock

10.Common Stock

The following transactions occurred since December 31, 2016:  

Reverse Stock Split

On May 5, 2017 the Company effected a one-for-ten reverse stock split of the outstanding shares of the Company’s common stock, together with a corresponding proportional reduction in the number of authorized shares of the Company’s capital stock.  Each ten shares of the Company’s common stock, par value $0.0001 per share, issued and outstanding at the effective time of the reverse stock split were reclassified and combined into one share of common stock par value $0.0001 per share. The number of shares of common stock and preferred stock the Company is authorized to issue was reduced to 50 million and 10 million, respectively.  All share and per share amounts of common stock, stock options, stock warrants and restricted stock units have been restated for all periods to give retroactive effect to the reverse stock split.  Accordingly, an amount equal to the par value of the decreased shares resulting from the reverse stock split was reclassified from “Common stock” to “Additional paid-in capital.” 

Warrant Exercises

During the six months ended June 30, 2017, warrant holders exercised warrants to purchase shares of the Company’s common stock for cash of $5,354,093 and the Company issued 1,652,623 shares.

Stock Option Exercises

During the six months ended June 30, 2017, a stock option holder exercised options to purchase shares of the Company’s common stock for cash of $77,500 and the Company issued 25,000 shares.

Compensatory Shares

During the six months ended June 30, 2017, the Company issued 7,500 shares to a privately held investor relations firm in exchange for investor relations services.  The aggregate market value of the stock issued was $12,750.

Registered Direct Offering

On June 12, 2017 the Company closed a registered direct public offering of 3,030,304 shares of common stock and warrants to purchase up to 1,515,152 shares of common stock.  The common stock and warrants were sold in units, consisting of a share of common stock and a warrant to purchase 0.5 shares of common stock, at a price of $3.30 per unit, with an exercise price for the warrants of $4.00 per share.  The total gross proceeds of the offering were $10,000,003.  The warrants issued will become exercisable beginning six months after the closing date, and will remain exercisable until the five-year anniversary of the initial exercise date, and were recorded as liabilities at fair value. 

A summary of the allocation of the proceeds of the offering is shown below:

Gross Proceeds:	$	10,000,003
Allocated to warrant liabilities		3,673,168
Allocated to common stock and additional paid-in capital		6,326,835
Total allocated gross proceeds:	$	10,000,003

The Company also issued warrants to purchase up to an aggregate 181,818 shares of common stock to the placement agent in the offering.  The closing costs for the offering of $1,193,052included $434,320 for the placement agentwarrants and $758,732for placement agent and other fees.  Based on the estimated fair value of the stock and warrants in the units, the Company allocated $333,050 to financing expense for the warrants and $860,002 as stock issuance costs.

XML

Stock-Based Compensation

6 Months Ended

Jun. 30, 2017

Stock-Based Compensation [Abstract]

Stock-Based Compensation

11. Stock-Based Compensation

As of June 30, 2017, the Company had 1,937,871 options to purchase common stock and 54,300 restricted stock units (“RSUs”) outstanding.

At the Company’s Annual Meeting of Shareholders held on June 10, 2013, the Company’s shareholders voted to approve the Rexahn Pharmaceuticals, Inc. 2013 Stock Option Plan (the “2013 Plan”).  Under the 2013 Plan, the Company grants equity awards to key employees, directors and consultants of the Company.  The Company initially reserved 1,700,000 shares of common stock for issuance pursuant to the 2013 Plan, and on April 11, 2017, the Company’s shareholders approved an increase of 1,700,000 shares of common stock reserved for issuance pursuant to the 2013 Plan.As of June 30, 2017, there were 1,540,871 options and 54,300 RSUs outstanding under the 2013 Plan, and 1,804,079 shares were available for issuance.

On August 5, 2003, the Company established a stock option plan (the “2003 Plan”).  Under the 2003 Plan, the Company granted stock options to key employees, directors and consultants of the Company.  With the adoption of the 2013 Plan, no new stock options may be issued under the 2003 Plan, but previously issued options under the 2003 Plan remain outstanding until their expiration.  As of June 30, 2017, there were 385,000 options outstanding under the 2003 Plan. 

In March 2016, the Company granted to a third party an option to purchase up to 12,000 shares of the Company’s common stock.  These were the only Company stock options outstanding as of June 30, 2017, that were not issued pursuant to the 2013 Plan or the 2003 Plan.

Accounting for Awards

Stock-based compensation expense is the estimated fair value of options and RSUs granted amortized on a straight-line basis over the requisite vesting service period for the entire portion of the award. Total stock-based compensation recognized by the Company for the three and six months ended June 30, 2017 and 2016 is as follows:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2017		2016		2017		2016
Statement of operations line item:
General and administrative	$	207,587	$	224,786	$	395,898	$	440,113
Research and development		80,478		126,390		166,494		254,074
Total	$	288,065	$	351,176	$	562,392	$	694,187

No income tax benefit has been recognized in the statement of operations for stock-based compensation arrangements as the Company has provided for a 100% valuation allowance on its deferred tax assets.

Summary of Stock Option Transactions

There were 393,260 stock options granted at exercise prices ranging from $1.84 to $6.18 with an aggregate fair value of $620,185 during the six months ended June 30, 2017.  There were 448,707 stock options granted at exercise prices ranging from $2.70 to $3.70 with an aggregate fair value of $927,644 during the six months ended June 30, 2016.

The majority of the option grants to employees vest over a four-year period from the grant date. The vesting period is either (i) 30%,  30% and 40% on the first,  second and third anniversaries of the grant date, respectively, or (ii) 25% each on the first four anniversaries of the grant date.  With the exception of the options granted in March 2016, which have a three-year term, options generally expire ten years from the date of grant. For the majority of grants to non-employee consultants of the Company, the vesting period is between one and three years, subject to the fulfillment of certain conditions in the individual stock agreements, or 100% upon the occurrence of certain events specified in the individual stock agreements.

The fair value of options at the date of grant was estimated using the Black-Scholes option pricing model.  The Company took into consideration guidance under ASC 718, “Compensation-Stock Compensation” and Staff Accounting Bulletin No. 107 (“SAB 107”) when reviewing and updating assumptions.  The expected volatility is based upon historical volatility of the Company’s stock.  The expected term is based upon the simplified method as allowed under SAB 107.

The assumptions made in calculating the fair values of options are as follows:

	Six Months Ended June 30,
	2017		2016
Black-Scholes assumptions
Expected dividend yield	0	%	0	%
Expected volatility	69-79	%	32-75	%
Risk free interest rate	1.8-2.0	%	0.6-1.4	%
Expected term (in years)	5.5-6 years		2-6 years

A summary of stock option activity for the six months ended June 30, 2017 is as follows:

	Number of Options		Weighted Average Exercise Price	Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding, January 1, 2017	1,690,037	$	6.20	7.3 years	$	-
Granted	393,260		2.46
Exercised	(25,000)		3.10
Expired	(15,000)		16.07
Cancelled	(105,426)		3.77
Outstanding, June 30, 2017	1,937,871	$	5.54	7.4 years	$	342,455
Exercisable, June 30, 2017	1,120,784	$	6.73	6.3 years	$	6,858

The total intrinsic value of options exercised was $97,872 for the three and six months ended June 30, 2017.  There were no stock options exercised during the three and six months ended June 30, 2016.  The weighted average fair value of the options granted was $1.58 and $2.06 for the six months ended June 30, 2017 and 2016, respectively.

A summary of the Company’s unvested options as of June 30, 2017 and changes during the six months ended June 30, 2017 is presented below:

	2017
	Number of  Options	Weighted Average Fair Value at Grant Date
Unvested at January 1, 2017	897,123	$	3.21
Granted	393,260	$	1.58
Vested	(378,594)	$	3.06
Cancelled	(94,702)	$	2.15
Unvested at June 30, 2017	817,087	$	2.63

As of June 30, 2017 there was $1,749,516 of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average vesting period of 2.6 years.

Summary of Restricted Stock Unit Transactions

The Company began granting RSUs to employees in 2017.  There were 62,300 RSUs granted with an aggregate fair value of $114,632 during the six months ended June 30, 2017.  The fair value of an RSU award is the closing price of the Company’s common stock on the date of grant.

A summary of RSU activity for the six months ended June 30, 2017 is as follows:

	Number of RSUs		Weighted Average Grant Date Fair Value
Outstanding, January 1, 2017	-	$	-
Granted	62,300		1.84
Vested and Released	-		-
Cancelled	(8,000)		1.84
Outstanding, June 30, 2017	54,300	$	1.84

As of June 30, 2017, there was $89,717 of total unrecognized compensation cost related to unvested RSUs which is expected to be recognized over a weighted average vesting period of 3.7 years.

XML

Warrants

6 Months Ended

Jun. 30, 2017

Warrants [Abstract]

Warrants

12. Warrants

As of June 30, 2017, warrants to purchase up to 5,288,466 shares were outstanding, having exercise prices ranging from $3.00to $12.80 and expiration dates ranging from December 4, 2017 to December 12, 2022.  

	2017			2016
	Number of warrants	Weighted average exercise price		Number of warrants	Weighted average exercise price
Balance, January 1	5,452,691	$	4.92	2,649,199	$	7.97
Issued during the period	1,696,970	$	4.01	1,250,000	$	4.20
Exercised during the period	(1,861,195)	$	3.51	-	$	-
Expired during the period	-	$	-	-	$	-
Balance, June 30	5,288,466	$	5.13	3,899,199	$	6.76

At June 30, 2017 the weighted average remaining contractual life of the outstanding warrants was 4.1 years.

The warrants issued to investors in the December 2012, November 2015, March 2016 and September 2016 offerings contain a provision for net cash settlement in the event of a fundamental transaction (contractually defined to include a merger, sale of substantially all assets, tender offer or share exchange).  Pursuant to the November 2015, March 2016, and September 2016 warrants, if fundamental transaction occurs, then the warrant holder has the option to receive cash, equal to the fair value of the remaining unexercised portion of the warrant.  The option is available to holders of the December 2012 warrants only if the consideration issued in the fundamental transaction consists of cash or stock in a non-public company.  Due to these contingent redemption provisions, the warrants require liability classification in accordance with ASC 480 and are recorded at fair value.   Holders of the June 2017 warrants contain a provision that allows the holder to opt for cash settlement in a fundamental transaction that was approved by, or required to be approved by, the board of directors of the Company. All of the Company’s outstanding warrants provide the holder the option as to the type of consideration received if the holders of common stock receive an option as to their consideration. In addition, all of the Company’s outstanding warrants contain a cashless exercise provision that is exercisable only in the event that a registration statement is not effective. That provision may not be operative if an effective registration statement is not available because an exemption under the U.S. securities laws may not be available to issue unregistered shares.  As a result, net cash settlement may be required, and the warrants require liability classification.

ASC 820 provides requirements for disclosure of liabilities that are measured at fair value on a recurring basis in periods subsequent to the initial recognition.  Fair values for warrants were determined using the Binomial Lattice (“Lattice”) valuation technique. The Lattice model provides for dynamic assumptions regarding volatility and risk-free interest rates within the total period to maturity. Accordingly, within the contractual term, the Company provided multiple date intervals over which multiple volatilities and risk free interest rates were used. These intervals allow the Lattice model to project outcomes along specific paths that consider volatilities and risk free rates that would be more likely in an early exercise scenario.

Significant assumptions are determined as follows:

Trading market values—Published trading market values;

Exercise price—Stated exercise price;

Term—Remaining contractual term of the warrant;

Volatility—Historical trading volatility for periods consistent with the remaining terms; and

Risk-free rate—Yields on zero coupon government securities with remaining terms consistent with the remaining terms of the warrants.

Due to the fundamental transaction provision, which could provide for early redemption of the warrants, the model also considered the probability the Company would enter into a fundamental transaction during the remaining term of the warrant. Because the Company is not yet achieving positive cash flow, management believes the probability of a fundamental transaction occurring over the term of the warrant is unlikely and therefore estimates the probability of entering into a fundamental transaction to be 5%.  For valuation purposes, the Company also assumed that if such a transaction did occur, it was more likely to occur towards the end of the term of the warrants.

The significant unobservable inputs used in the fair value measurement of the warrants include management’s estimate of the probability that a fundamental transaction may occur in the future.  Significant increases (decreases) in the probability of occurrence would result in a significantly higher (lower) fair value measurement.

The following table summarizes the fair value of the warrants as of the respective balance sheet dates:

	Fair Value as of:
Warrant Issuance:	June 30, 2017		December 31, 2016
December 2012 Investor Warrants	$	7,316	$	49
July 2013 Investor Warrants		183,108		2,060
October 2013 Investor Warrants		241,999		3,708
January 2014 Investor Warrants		303,762		714
November 2015 Investor Warrants		2,362,538		260,500
November 2015 Placement Agent Warrants		5,573		13,542
March 2016 Investor Warrants		1,219,172		358,945
March 2016 Placement Agent Warrants		-		21,320
September 2016 Investor Warrants		1,795,810		854,640
September 2016 Placement Agent Warrants		-		57,888
June 2017 Investor Warrants		3,289,759		-
June 2017 Placement Agent Warrants		387,554		-
Total:	$	9,796,591	$	1,573,366

The following table summarizes the number of shares indexed to the warrants as of the respective balance sheet dates:

	Number of Shares indexed as of:
Warrant Issuance	June 30, 2017	December 31, 2016
December 2012 Investor Warrants	17,430	17,430
July 2013 Investor Warrants	200,000	200,000
October 2013 Investor Warrants	231,732	231,732
January 2014 Investor Warrants	476,193	476,193
November 2015 Investor Warrants	1,250,001	1,250,001
November 2015 Placement Agent Warrants	3,334	83,335
March 2016 Investor Warrants	607,806	1,171,875
March 2016 Placement Agent Warrants	-	78,125
September 2016 Investor Warrants	805,000	1,800,000
September 2016 Placement Agent Warrants	-	144,000
June 2017 Investor Warrants	1,515,152	-
June 2017 Placement Agent Warrants	181,818	-
Total:	5,288,466	5,452,691

The assumptions used in calculating the fair values of the warrants are as follows:

	June 30, 2017			December 31, 2016
Trading market prices	$	2.86		$	1.40
Estimated future volatility		104	%		104	%
Dividend		-			-
Estimated future risk-free rate		1.23-2.31	%		1.06-2.44	%
Equivalent volatility		106-129	%		51-60	%
Equivalent risk-free rate		0.87-1.48	%		0.59-1.25	%

Changes in the fair value of the warrant liabilities, carried at fair value, reported as “unrealized gain (loss) on fair value of warrants” in the statement of operations:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
		2017		2016		2017		2016
Expired Warrants	$	-	$	771	$	-	$	2,590
December 2012 Investor Warrants		35,454		5,911		(7,267)		7,278
July 2013 Investor Warrants		368,332		63,246		(181,048)		93,900
October 2013 Investor Warrants		438,919		103,166		(238,291)		129,607
January 2014 Investor Warrants		778,762		92,428		(303,048)		117,714
November 2015 Investor Warrants		2,017,712		875,913		(2,102,038)		1,204,626
November 2015 Placement Agent Warrants		(96,560)		58,276		(368,385)		80,160
March 2016 Investor Warrants		702,730		860,121		(3,229,781)		1,252,266
March 2016 Placement Agent Warrants		(82,867)		58,258		(351,899)		85,904
September 2016 Investor Warrants		928,592		-		(5,313,599)		-
September 2016 Placement Agent Warrants		-		-		(503,150)		-
June 2017 Investor Warrants		383,409		-		383,409		-
June 2017 Placement Agent Warrants		46,766		-		46,766		-
Total:	$	5,521,249	$	2,118,090	$	(12,168,331)	$	2,974,045

XML

Income Taxes

6 Months Ended

Jun. 30, 2017

Income Taxes [Abstract]

Income Taxes

13. Income Taxes

No provision for federal and state income taxes was required for the three and six months ended June 30, 2017 and 2016 due to the Company’s operating losses and increased deferred tax asset valuation allowance.  At June 30, 2017 and December 31, 2016, the Company had unused net operating loss carry-forwards of approximately $119,618,000 and $111,605,000 respectively, which expire at various dates through 2037.  Some of this amount may be subject to annual limitations under certain provisions of the Internal Revenue Code related to “changes in ownership.” 

As of June 30, 2017 and December 31, 2016, the deferred tax assets related to the aforementioned carry-forwards have been fully offset by valuation allowances, because significant utilization of such amounts is not presently expected in the foreseeable future. 

Deferred tax assets and valuation allowances consist of:

	June 30,		December 31,
	2017		2016
Net Operating Loss Carryforwards	$	46,651,000	$	43,526,000
Stock Compensation Expense		2,109,000		1,968,000
Book tax differences on assets and liabilities		410,000		547,000
Valuation Allowance		(49,170,000)		(46,041,000)
Net Deferred Tax Assets	$	-	$	-

The Company files income tax returns in the U.S. federal and Maryland state jurisdictions.  Tax years for fiscal 2013 through 2016 are open and potentially subject to examination by the federal and Maryland state taxing authorities.

XML

Commitments And Contingencies

6 Months Ended

Jun. 30, 2017

Commitments And Contingencies [Abstract]

Commitments And Contingencies

14.Commitments and Contingencies

a)The Company has contracted with various vendors for research and development services, with terms that require payments over the terms of the agreements, usually ranging from two to 36 months. The costs to be incurred are estimated and are subject to revision. As of June 30, 2017, the total estimated cost to complete these agreements was approximately $8,500,000.  All of these agreements may be terminated by either party upon appropriate notice as stipulated in the respective agreements.

b)On June 22, 2009, the Company entered into a License Agreement with Korea Research Institute of Chemical Technology (“KRICT”) to acquire the rights to all intellectual property related to quinoxaline-piperazine derivatives that were synthesized under a Joint Research Agreement.  The initial license fee was $100,000, all of which was paid as of December 31, 2009.  The agreement with KRICT calls for a one-time milestone payment of $1,000,000 within 30 days after the first achievement of marketing approval of the first commercial product arising out of or in connection with the use of KRICT’s intellectual property.  As of June 30, 2017, the milestone has not occurred.

c)Office Space Lease

On June 5, 2009, the Company entered into a commercial lease agreement for 5,466 square feet of office space in Rockville, Maryland.  The lease was amended on June 7, 2013 to extend the term until June 30, 2019. 

On July 26, 2014 the lease was amended to add 1,727 square feet of office space for a term beginning on September 1, 2014 and ending on August 31, 2015, which was subsequently renewed for additional one-year terms, beginning on September 1, 2015 and 2016, and a 22-month term beginning September 1, 2017 and expiring on June 30, 2019. Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges.

Rent paid under the Company’s lease during the three months ended June 30, 2017 and 2016was $50,898and $51,301, respectively, and rent paid during the six months ended June 30, 2017 and 2016 was $101,796 and $102,603, respectively.

Laboratory Lease

On April 20, 2015, the Company signed a five-year lease agreement for 2,552 square feet of laboratory space commencing on July 1, 2015 and ending on June 30, 2020.  Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges. Rent paid under this lease during the three months ended June 30, 2017 and 2016 was $15,771 and$15,312, respectively, and rent paid during the six months ended June 30, 2017 was $31,543 and $30,624.

Future rental payments over the next five years for all leases are as follows:

For the remaining six months ending December 31:	2017	$	137,360
For the year ending December 31:	2018		279,274
	2019		176,080
	2020		34,468
	Total	$	627,182

d)The Company has established a 401(k) plan for its employees.  The Company has elected to match 100% of the first 3% of an employee’s compensation plus 50% of an additional 2% of the employee’s deferral. Expense related to this matching contribution aggregated to $34,606and $31,587for the three months ended June 30, 2017 and 2016, respectively, and $71,083 and $63,089 for the six months ended June 30, 2017 and 2016, respectively.

e)In July 2013, the Company entered into an exclusive license agreement with the University of Maryland, Baltimore for a novel drug delivery platform, Nano-Polymer Drug Conjugate Systems.  RX-21101 is the Company’s first drug candidate utilizing this platform.  The agreement requires the Company to make payments to the University of Maryland if RX-21101 or any products from the licensed delivery platform achieve development milestones.  As of June 30, 2017, no development milestones have occurred.

f)In October 2013, the Company signed an exclusive license agreement with the Ohio State Innovation Foundation, for a novel oligonucleotide drug delivery platform, Lipid-Coated Albumin Nanoparticle.  The agreement requires the Company to make payments to the Ohio State Innovation Foundation if any products from the licensed delivery platform achieve development milestones.  As of June 30, 2017, no development milestones have occurred.

XML

Fair Value Measurements

6 Months Ended

Jun. 30, 2017

Fair Value Measurements [Abstract]

Fair Value Measurements

15.  Fair Value Measurements

ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, not adjusted for transaction costs.  ASC 820 also establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels giving the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). 

The three levels are described below:

Level 1 Inputs	—	Unadjusted quoted prices in active markets for identical assets or liabilities that are accessible by the Company;
Level 2 Inputs	—	Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly; and
Level 3 Inputs	—	Unobservable inputs for the asset or liability including significant assumptions of the Company and other market participants.

The following tables present assets and liabilities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy.  There have been no changes in the methodologies used at June 30, 2017 and December 31, 2016.

de

Fair Value Measurements at June 30, 2017
	Total		Level 1		Level 2		Level 3
Assets:
Commercial Paper		3,215,330		-		3,215,330		-
Corporate Bonds		14,770,830		-		14,770,830		-
Total Assets:	$	17,986,160	$	-	$	17,986,160	$	-
Liabilities:
Warrant Liabilities	$	9,796,591	$	-	$	-	$	9,796,591

Fair Value Measurements at December 31, 2016
	Total		Level 1		Level 2		Level 3
Assets:
Certificates of Deposit	$	720,197	$	-	$	720,197	$	-
Commercial Paper		3,985,740		-		3,985,740		-
Corporate Bonds		4,031,170		-		4,031,170		-
Total Assets:	$	8,737,107	$	-	$	8,737,107	$	-
Liabilities:
Warrant Liabilities	$	1,573,366	$	-	$	-	$	1,573,366

The fair value of the Company’s Level 2 marketable securities is determined by using quoted prices from independent pricing services that use market data for comparable securities in active or inactive markets.  A variety of data inputs, including benchmark yields, interest rates, known historical trades and broker dealer quotes are used with pricing models to determine the quoted prices.

The fair value methodology for the warrant liabilities is disclosed in Note 12.

The carrying amounts reported in the financial statements for cash and cash equivalents (Level 1), approximate fair value because of the short term maturity of these financial instruments.

The following table sets forth a reconciliation of changes for the six months ended June 30, 2017 and 2016 in the fair value of the liabilities classified as Level 3 in the fair value hierarchy:

	Warrant Liabilities
Balance at January 1, 2017	$	1,573,366
Additions		4,107,488
Unrealized losses, net		12,168,331
Transfers out of level 3		(8,052,594)
Balance at June 30, 2017	$	9,796,591

	Warrant Liabilities
Balance at January 1, 2016	$	2,739,163
Additions		2,575,860
Unrealized gains, net		(2,974,045)
Transfers out of level 3		-
Balance at June 30, 2016	$	2,340,978

Additions consist of the fair value of warrant liabilities upon issuance.  Transfers out of Level 3 for warrant liabilities consist of warrant exercises, where the liability is converted to additional paid-in capital upon exercise.  The Company’s policy is to recognize transfers in and transfers out as of the actual date of the event or change in circumstance that caused the transfer.

XML

Operations And Organization (Policies)

6 Months Ended

Jun. 30, 2017

Operations And Organization [Abstract]

Operations

Operations

Rexahn Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, is a biopharmaceutical company whose principal operations are the discovery, development and commercialization of innovative treatments for cancer.  The Company had an accumulated deficit of $135,688,177 at June 30, 2017 and anticipates incurring losses through fiscal year 2017 and beyond.  The Company has not yet generated commercial revenues and has funded its operating losses to date through the sale of shares of its common stock and warrants to purchase shares of its common stock, convertible debt, interest income from cash, cash equivalents and marketable securities, and proceeds from reimbursed research and development costs.  The Company believes that its cash, cash equivalents, and marketable securities will be sufficient to cover its cash flow requirements for its current activities for at least the next 12 months from the date these financial statements were issued.  Management believes it has the capability of managing the Company’s operations within existing cash available by focusing on select research and development activities, selecting projects in conjunction with potential financings and milestones, and efficiently managing the Company’s general and administrative affairs.

Basis of Presentation

Basis of Presentation

The accompanying unaudited condensed financial statements of the Company have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission for interim financial information.  Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete financial statements.  In the opinion of the Company’s management, all adjustments (consisting of only normal recurring accruals) considered necessary for a fair presentation of the Company’s financial position as of June 30, 2017 and December 31, 2016 and of the results of operations and comprehensive income (loss) for the three and six months ended June 30, 2017 and 2016 and cash flows for the six months ended June 30, 2017 and 2016 have been included.  Operating results for the three and six months ended June 30, 2017 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2017. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the “2016 Form 10-K”).  Information included in the condensed balance sheet as of December 31, 2016 has been derived from the Company’s audited financial statements for the year ended December 31, 2016 included in the 2016 Form 10-K.

Use of Estimates

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future.  Actual results may ultimately differ from these estimates.  These estimates are reviewed periodically, and as adjustments become necessary, they are reported in earnings in the period in which they become available.

XML

Recent Accounting Pronouncements Affecting the Company (Policies)

6 Months Ended

Jun. 30, 2017

Recent Accounting Pronouncements Affecting the Company [Abstract]

Recent Accounting Pronouncements Affecting the Company

Revenue from Contracts with Customers

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company should recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services, and provides a revenue recognition framework in accordance with this principle.  On August 12, 2015, the FASB issued ASU 2015-14, which defers the effective date of ASU 2014-09 by one year to December 15, 2017 for annual reporting periods beginning after that date and interim periods therein.  Early adoption of the standard is permitted.  The Company is currently evaluating the impact that the adoption of this guidance will have on its financial statements and future operating results.

Leases

In February 2016, the FASB issued ASU 2016-02, “Leases,” which requires an entity to recognize assets and liabilities arising from leases on the balance sheet and to provide additional disclosures about leasing arrangements.  ASU 2016-02 will be effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.

Compensation-Stock Compensation

In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation: Improvements to Employee Share Based Payment Accounting,” which includes multiple provisions intended to simplify various aspects of accounting for share-based payments.  The guidance is effective for reporting periods beginning after December 15, 2016, with early adoption permitted.  The Company adopted this guidance for the three months ended March 31, 2017.  This pronouncement did not have a material impact on the financial statements.

XML

Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2017

Marketable Securities [Abstract]

Schedule Of Cost And Fair Value Of Marketable Securities

		June 30, 2017
		Cost		Gross Unrealized		Gross Unrealized		Fair
		Basis		Gains		Losses		Value
Commercial Paper	$	3,220,126	$	-	$	(4,796)	$	3,215,330
Corporate Bonds		14,791,739		-		(20,909)		14,770,830
Total Marketable Securities	$	18,011,865	$	-	$	(25,705)	$	17,986,160
		December 31, 2016
		Cost		Gross Unrealized		Gross Unrealized		Fair
		Basis		Gains		Losses		Value
Certificates of Deposit	$	720,000	$	197	$	-	$	720,197
Commercial Paper		3,987,424		-		(1,684)		3,985,740
Corporate Bonds		4,035,805		-		(4,635)		4,031,170
Total Marketable Securities	$	8,743,229	$	197	$	(6,319)	$	8,737,107

Schedule Of Cost And Fair Value By Contractual Maturity

Maturity	Cost Basis		Fair Value
Less than 1 year	$	12,274,138	$	12,257,650
1 to 5 years		5,737,727		5,728,510
Total Marketable Securities	$	18,011,865	$	17,986,160

XML

Prepaid Expenses And Other Current Assets (Tables)

6 Months Ended

Jun. 30, 2017

Prepaid Expenses And Other Current Assets [Abstract]

Schedule Of Prepaid Expenses And Other Current Assets

	June 30,		December 31,
	2017		2016
Deposits on contracts	$	532,602	$	179,476
Prepaid expenses and other current assets		667,039		429,041
	$	1,199,641	$	608,517

XML

Equipment, Net (Tables)

6 Months Ended

Jun. 30, 2017

Equipment, Net [Abstract]

Schedule Of Equipment, Net

	June 30,		December 31,
	2017		2016
Furniture and fixtures	$	78,794	$	78,794
Office and computer equipment		118,358		113,932
Lab equipment		445,134		431,650
Leasehold improvements		133,762		133,762
Total equipment		776,048		758,138
Less: Accumulated depreciation and amortization		(689,438)		(669,488)
Net carrying amount	$	86,610	$	88,650

XML

Accounts Payable And Accrued Expenses (Tables)

6 Months Ended

Jun. 30, 2017

Accounts Payable And Accrued Expenses [Abstract]

Schedule Of Accounts Payable And Accrued Expenses

	June 30,		December 31,
	2017		2016
Trade payables	$	509,085	$	430,013
Accrued expenses		167,297		141,190
Accrued research and development contract costs		715,065		499,889
Payroll liabilities		526,292		811,408
	$	1,917,739	$	1,882,500

XML

Other Liabilities (Tables)

6 Months Ended

Jun. 30, 2017

Other Liabilities [Abstract]

Schedule Of Deferred Lease Incentive

	June 30,		December 31,
	2017		2016
Deferred lease incentive	$	154,660	$	154,660
Less accumulated amortization		(129,773)		(123,551)
Balance	$	24,887	$	31,109

XML

Common Stock (Tables)

6 Months Ended

Jun. 30, 2017

Common Stock [Abstract]

Summary Of Allocation Of Proceeds From Offering

Gross Proceeds:	$	10,000,003
Allocated to warrant liabilities		3,673,168
Allocated to common stock and additional paid-in capital		6,326,835
Total allocated gross proceeds:	$	10,000,003

XML

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Stock-Based Compensation [Abstract]

Summary Of Stock Compensation Expense

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2017		2016		2017		2016
Statement of operations line item:
General and administrative	$	207,587	$	224,786	$	395,898	$	440,113
Research and development		80,478		126,390		166,494		254,074
Total	$	288,065	$	351,176	$	562,392	$	694,187

Schedule Of Assumptions Made In Calculating The Fair Value Of Options

	Six Months Ended June 30,
	2017		2016
Black-Scholes assumptions
Expected dividend yield	0	%	0	%
Expected volatility	69-79	%	32-75	%
Risk free interest rate	1.8-2.0	%	0.6-1.4	%
Expected term (in years)	5.5-6 years		2-6 years

Summary Of Stock Options Outstanding

	Number of Options		Weighted Average Exercise Price	Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding, January 1, 2017	1,690,037	$	6.20	7.3 years	$	-
Granted	393,260		2.46
Exercised	(25,000)		3.10
Expired	(15,000)		16.07
Cancelled	(105,426)		3.77
Outstanding, June 30, 2017	1,937,871	$	5.54	7.4 years	$	342,455
Exercisable, June 30, 2017	1,120,784	$	6.73	6.3 years	$	6,858

Summary Of Unvested Shares

	2017
	Number of  Options	Weighted Average Fair Value at Grant Date
Unvested at January 1, 2017	897,123	$	3.21
Granted	393,260	$	1.58
Vested	(378,594)	$	3.06
Cancelled	(94,702)	$	2.15
Unvested at June 30, 2017	817,087	$	2.63

Summary Of RSU Activity

	Number of RSUs		Weighted Average Grant Date Fair Value
Outstanding, January 1, 2017	-	$	-
Granted	62,300		1.84
Vested and Released	-		-
Cancelled	(8,000)		1.84
Outstanding, June 30, 2017	54,300	$	1.84

XML

Warrants (Tables)

6 Months Ended

Jun. 30, 2017

Warrants [Abstract]

Summary Of Changes In Warrants Outstanding During The Period

	2017			2016
	Number of warrants	Weighted average exercise price		Number of warrants	Weighted average exercise price
Balance, January 1	5,452,691	$	4.92	2,649,199	$	7.97
Issued during the period	1,696,970	$	4.01	1,250,000	$	4.20
Exercised during the period	(1,861,195)	$	3.51	-	$	-
Expired during the period	-	$	-	-	$	-
Balance, June 30	5,288,466	$	5.13	3,899,199	$	6.76

Schedule Of Fair Value Of Warrants Issued

	Fair Value as of:
Warrant Issuance:	June 30, 2017		December 31, 2016
December 2012 Investor Warrants	$	7,316	$	49
July 2013 Investor Warrants		183,108		2,060
October 2013 Investor Warrants		241,999		3,708
January 2014 Investor Warrants		303,762		714
November 2015 Investor Warrants		2,362,538		260,500
November 2015 Placement Agent Warrants		5,573		13,542
March 2016 Investor Warrants		1,219,172		358,945
March 2016 Placement Agent Warrants		-		21,320
September 2016 Investor Warrants		1,795,810		854,640
September 2016 Placement Agent Warrants		-		57,888
June 2017 Investor Warrants		3,289,759		-
June 2017 Placement Agent Warrants		387,554		-
Total:	$	9,796,591	$	1,573,366

Summary Of Shares Indexed To The Warrants

	Number of Shares indexed as of:
Warrant Issuance	June 30, 2017	December 31, 2016
December 2012 Investor Warrants	17,430	17,430
July 2013 Investor Warrants	200,000	200,000
October 2013 Investor Warrants	231,732	231,732
January 2014 Investor Warrants	476,193	476,193
November 2015 Investor Warrants	1,250,001	1,250,001
November 2015 Placement Agent Warrants	3,334	83,335
March 2016 Investor Warrants	607,806	1,171,875
March 2016 Placement Agent Warrants	-	78,125
September 2016 Investor Warrants	805,000	1,800,000
September 2016 Placement Agent Warrants	-	144,000
June 2017 Investor Warrants	1,515,152	-
June 2017 Placement Agent Warrants	181,818	-
Total:	5,288,466	5,452,691

Schedule Of Assumptions Used In Calculating Fair Value Of Warrants

	June 30, 2017			December 31, 2016
Trading market prices	$	2.86		$	1.40
Estimated future volatility		104	%		104	%
Dividend		-			-
Estimated future risk-free rate		1.23-2.31	%		1.06-2.44	%
Equivalent volatility		106-129	%		51-60	%
Equivalent risk-free rate		0.87-1.48	%		0.59-1.25	%

Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
		2017		2016		2017		2016
Expired Warrants	$	-	$	771	$	-	$	2,590
December 2012 Investor Warrants		35,454		5,911		(7,267)		7,278
July 2013 Investor Warrants		368,332		63,246		(181,048)		93,900
October 2013 Investor Warrants		438,919		103,166		(238,291)		129,607
January 2014 Investor Warrants		778,762		92,428		(303,048)		117,714
November 2015 Investor Warrants		2,017,712		875,913		(2,102,038)		1,204,626
November 2015 Placement Agent Warrants		(96,560)		58,276		(368,385)		80,160
March 2016 Investor Warrants		702,730		860,121		(3,229,781)		1,252,266
March 2016 Placement Agent Warrants		(82,867)		58,258		(351,899)		85,904
September 2016 Investor Warrants		928,592		-		(5,313,599)		-
September 2016 Placement Agent Warrants		-		-		(503,150)		-
June 2017 Investor Warrants		383,409		-		383,409		-
June 2017 Placement Agent Warrants		46,766		-		46,766		-
Total:	$	5,521,249	$	2,118,090	$	(12,168,331)	$	2,974,045

XML

Income Taxes (Tables)

6 Months Ended

Jun. 30, 2017

Income Taxes [Abstract]

Schedule Of Deferred Tax Assets And Valuation Allowance

	June 30,		December 31,
	2017		2016
Net Operating Loss Carryforwards	$	46,651,000	$	43,526,000
Stock Compensation Expense		2,109,000		1,968,000
Book tax differences on assets and liabilities		410,000		547,000
Valuation Allowance		(49,170,000)		(46,041,000)
Net Deferred Tax Assets	$	-	$	-

XML

Commitments And Contingencies (Tables)

6 Months Ended

Jun. 30, 2017

Commitments And Contingencies [Abstract]

Schedule Of Future Rental Payments

For the remaining six months ending December 31:	2017	$	137,360
For the year ending December 31:	2018		279,274
	2019		176,080
	2020		34,468
	Total	$	627,182

XML

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Measurements [Abstract]

Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis

Fair Value Measurements at June 30, 2017
	Total		Level 1		Level 2		Level 3
Assets:
Commercial Paper		3,215,330		-		3,215,330		-
Corporate Bonds		14,770,830		-		14,770,830		-
Total Assets:	$	17,986,160	$	-	$	17,986,160	$	-
Liabilities:
Warrant Liabilities	$	9,796,591	$	-	$	-	$	9,796,591

Fair Value Measurements at December 31, 2016
	Total		Level 1		Level 2		Level 3
Assets:
Certificates of Deposit	$	720,197	$	-	$	720,197	$	-
Commercial Paper		3,985,740		-		3,985,740		-
Corporate Bonds		4,031,170		-		4,031,170		-
Total Assets:	$	8,737,107	$	-	$	8,737,107	$	-
Liabilities:
Warrant Liabilities	$	1,573,366	$	-	$	-	$	1,573,366

Reconciliation Of Changes In The Fair Value Of Liabilities

	Warrant Liabilities
Balance at January 1, 2017	$	1,573,366
Additions		4,107,488
Unrealized losses, net		12,168,331
Transfers out of level 3		(8,052,594)
Balance at June 30, 2017	$	9,796,591

	Warrant Liabilities
Balance at January 1, 2016	$	2,739,163
Additions		2,575,860
Unrealized gains, net		(2,974,045)
Transfers out of level 3		-
Balance at June 30, 2016	$	2,340,978

XML

Operations And Organization (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Operations And Organization [Abstract]
Accumulated deficit	$ 135,688,177	$ 115,024,209

XML

Marketable Securities (Narrative) (Details)	Jun. 30, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Fair value	$ 17,986,160	$ 8,737,107
Unrealized losses	$ 25,705	$ 6,319
3 Commercial Paper With Unrealized Losses [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position, less than one year | item	3
Fair value	$ 3,215,330
Unrealized losses	$ 4,796
14 Corporate Bond Securities With Unrealized Losses Less Than 12 Months [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position, less than one year | item	14
Fair value	$ 13,770,830
Unrealized losses	$ 20,909

XML

Marketable Securities (Schedule Of Cost And Fair Value Of Marketable Securities) (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 18,011,865	$ 8,743,229
Gross Unrealized Gains		197
Gross Unrealized Losses	(25,705)	(6,319)
Fair value	17,986,160	8,737,107
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	3,220,126	3,987,424
Gross Unrealized Losses	(4,796)	(1,684)
Fair value	3,215,330	3,985,740
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	14,791,739	4,035,805
Gross Unrealized Losses	(20,909)	(4,635)
Fair value	$ 14,770,830	4,031,170
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis		720,000
Gross Unrealized Gains		197
Fair value		$ 720,197

XML

Marketable Securities (Schedule Of Cost And Fair Value By Contractual Maturity) (Details)	Jun. 30, 2017 USD ($)
Marketable Securities [Abstract]
Less than 1 year, Cost Basis, Maturity	$ 12,274,138
1 to 5 years, Cost Basis, Maturity	5,737,727
Total Marketable Securities, Cost Basis, Maturity	18,011,865
Less than 1 year, Fair Value, Maturity	12,257,650
1 to 5 years, Fair Value, Maturity	5,728,510
Total Marketable Securities, Fair Value, Maturity	$ 17,986,160

XML

Prepaid Expenses And Other Current Assets (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Prepaid Expenses And Other Current Assets [Abstract]
Deposits on contracts	$ 532,602	$ 179,476
Prepaid expenses and other current assets	667,039	429,041
Total prepaid expenses and other current assets	$ 1,199,641	$ 608,517

XML

Equipment, Net (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total equipment	$ 776,048	$ 758,138
Less: Accumulated depreciation and amortization	(689,438)	(669,488)
Net carrying amount	86,610	88,650
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total equipment	78,794	78,794
Office And Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment	118,358	113,932
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment	445,134	431,650
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total equipment	$ 133,762	$ 133,762

XML

Accounts Payable And Accrued Expenses (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Accounts Payable And Accrued Expenses [Abstract]
Trade payables	$ 509,085	$ 430,013
Accrued expenses	167,297	141,190
Accrued research and development contract costs	715,065	499,889
Payroll liabilities	526,292	811,408
Total accounts payable and accrued expenses	$ 1,917,739	$ 1,882,500

XML

Deferred Research And Development Arrangements (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2003	Dec. 31, 2016
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred Research and Development Arrangement	$ 412,500		$ 412,500			$ 450,000
Rexgene Biotech Co., Ltd. [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development arrangement, one-time fee					$ 1,500,000
Reduction of research and development expenses	18,750	$ 18,750	$ 37,500	$ 37,500
Research and development period			20 years
Deferred Research and Development Arrangement	$ 412,500	$ 450,000	$ 412,500	$ 450,000
Royalties paid, percentage of net sales			3.00%

XML

Other Liabilities (Narrative) (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Other Liabilities [Abstract]
Accrued Rent	$ 40,925	$ 48,095

XML

Other Liabilities (Schedule Of Deferred Lease Incentive) (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Other Liabilities [Abstract]
Deferred lease incentive	$ 154,660	$ 154,660
Less accumulated amortization	(129,773)	(123,551)
Balance	$ 24,887	$ 31,109

XML

Net Income (Loss) Per Common Share (Details) - shares	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	7,280,637	7,142,728
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	1,177,987
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	1,031,356
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	54,300

XML

Common Stock (Narrative) (Details)			6 Months Ended
	Jun. 12, 2017 USD ($) $ / shares shares	May 05, 2017 $ / shares shares	Jun. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2016 shares	Dec. 31, 2016 $ / shares
Class of Stock [Line Items]
Reverse stock split		0.1
Common stock, par value | $ / shares			$ 0.0001		$ 0.0001
Preferred stock, par value | $ / shares			$ 0.0001		$ 0.0001
Cash paid for warrants exercised			$ 5,354,093
Shares issued for warrants exercised | shares			1,652,623
Stock options exercised			$ 77,500
Stock options exercised, shares | shares			25,000
Shares issued | shares	3,030,304
Number of warrants, issued | shares	1,515,152		1,696,970	1,250,000
Warrants issued per share of stock issued in unit offering | $ / shares	$ 0.5
Share Price | $ / shares	3.30
Stock Warrants, Exercise Price | $ / shares	$ 4.00
Proceeds from issuance	$ 10,000,003
Warrants issued included in closing costs | shares	181,818
Public offering closing costs	$ 1,193,052
Fair value of placement agent warrants	434,320
Cash paid in exchange for closing costs	758,732
Proceeds allocated to financing expense	333,050
Issuance cost incurred	$ 860,002
Stock issued for services | shares			7,500
Aggregate market value			$ 12,750
Common Stock [Member]
Class of Stock [Line Items]
Common stock, par value | $ / shares		$ 0.0001
Shares authorized | shares		50,000,000
Preferred Stock [Member]
Class of Stock [Line Items]
Shares authorized | shares		10,000,000

XML

Common Stock (Summary Of Allocation Of Proceeds From Offering) (Details)	Jun. 12, 2017 USD ($)
Common Stock [Abstract]
Allocated to warrant liabilities	$ 3,673,168
Allocated to Common stock and additional paid-in capital	6,326,835
Gross Proceeds:	$ 10,000,003

XML

Stock-Based Compensation (Narrative) (Details) - USD ($)		1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 11, 2017	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Jun. 10, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding			1,937,871		1,937,871
Number of RSUs outstanding			54,300		54,300
Share-based compensation expense			$ 288,065	$ 351,176	$ 562,392	$ 694,187
Income tax benefit from share-based compensation					$ 0
Valuation allowance on deferred tax assets					100.00%
Options exercised					25,000
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding			1,937,871		1,937,871		1,690,037
Vesting period					4 years
Percentage of Event Occurence to Vest					100.00%
Stock options granted					393,260
Stock option exercise price					$ 2.46
Intrinsic value of options exercised			$ 97,872	$ 0	$ 97,872	$ 0
Options exercised					25,000
Weighted average fair value at grant date, Vested					$ 1.58	$ 2.06
Unrecognized compensation cost			$ 1,749,516		$ 1,749,516
Weighted average vesting period, years					2 years 7 months 6 days
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs outstanding			54,300		54,300
Number of shares granted					62,300
Aggregate fair value					$ 114,632
Unrecognized compensation cost			$ 89,717		$ 89,717
Weighted average vesting period, years					3 years 8 months 12 days
March 2016 [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration of options from grant date, years					3 years
The 2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options authorized for issuance								1,700,000
Additional options authorized for issuance	1,700,000
Shares available for issuance			1,804,079		1,804,079
The 2013 Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding			1,540,871		1,540,871
The 2013 Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs outstanding			54,300		54,300
The 2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding			385,000		385,000
First Anniversary [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					30.00%
Second Anniversary [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					30.00%
Third Anniversary [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					40.00%
First Anniversary (B) [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Second Anniversary (B) [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Third Anniversary (B) [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Fourth Anniversary (B) [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Minimum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					1 year
Maximum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					3 years
Expiration of options from grant date, years					10 years
Exercise Price Range $1.84 to $6.18 [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted					393,260
Stock option grants fair value					$ 620,185
Exercise Price Range $1.84 to $6.18 [Member] | Minimum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price					$ 1.84
Exercise Price Range $1.84 to $6.18 [Member] | Maximum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price					$ 6.18
Exercise Price Range $2.70 to $3.70 [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted						448,707
Stock option grants fair value						$ 927,644
Exercise Price Range $2.70 to $3.70 [Member] | Minimum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price						$ 2.70
Exercise Price Range $2.70 to $3.70 [Member] | Maximum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price						$ 3.70
Third Party [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		12,000

XML

Stock-Based Compensation (Summary Of Stock Compensation Expense) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 288,065	$ 351,176	$ 562,392	$ 694,187
General and administrative [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	207,587	224,786	395,898	440,113
Research and development [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 80,478	$ 126,390	$ 166,494	$ 254,074

XML

Stock-Based Compensation (Schedule Of Assumptions Made In Calculating The Fair Value Of Options) (Details) - Stock Option [Member]	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Expected dividend yield	0.00%	0.00%
Expected volatility, minimum	69.00%	32.00%
Expected volatility, maximum	79.00%	75.00%
Risk free interest rate, minimum	1.80%	0.60%
Risk free interest rate, maximum	2.00%	1.40%
Minimum [Member]
Expected term (in years)	5 years 6 months	2 years
Maximum [Member]
Expected term (in years)	6 years	6 years

XML

Stock-Based Compensation (Summary Of Stock Options Outstanding) (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Number of options, Exercised	(25,000)
Number of options, Oustanding	1,937,871
Stock Option [Member]
Number of options, Oustanding	1,690,037
Number of Options, Granted	393,260
Number of options, Exercised	(25,000)
Number of options, Expired	(15,000)
Number of options, Cancelled	(105,426)
Number of options, Oustanding	1,937,871	1,690,037
Weighted average exercise price, Outstanding	$ 6.20
Weighted average exercise price, Granted	2.46
Weighted average exercise price, Exercised	3.10
Weighted average exercise price, Expired	16.07
Weighted average exercise price, Cancelled	3.77
Weighted average exercise price, Outstanding	$ 5.54	$ 6.20
Weighted average remaining contractual term, Outstanding	7 years 4 months 24 days	7 years 3 months 18 days
Aggregate intrinsic value, Outstanding	$ 342,455
Number of options, Exercisable	1,120,784
Weighted average exercise price, Exercisable	$ 6.73
Weighted average remaining contractual term, Exercisable	6 years 3 months 18 days
Aggregate intrinsic value, Exercisable	$ 6,858

XML

Stock-Based Compensation (Summary Of Unvested Shares) (Details) - Stock Option [Member]	6 Months Ended
	Jun. 30, 2017 $ / shares shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of Options, Unvested | shares	897,123
Number of Options, Granted | shares	393,260
Number of Options, Vested | shares	(378,594)
Number of Options, Cancelled | shares	(94,702)
Number of Options, Unvested | shares	817,087
Weighted Average Fair Value at Grant Date, Unvested | $ / shares	$ 3.21
Weighted Average Fair Value at Grant Date, Granted | $ / shares	1.58
Weighted Average Fair Value at Grant Date, Vested | $ / shares	3.06
Weighted Average Fair Value at Grant Date, Cancelled | $ / shares	2.15
Weighted Average Fair Value at Grant Date, Unvested | $ / shares	$ 2.63

XML

Stock-Based Compensation (Summary Of RSU Activity) (Details)	6 Months Ended
	Jun. 30, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs, Outstanding	54,300
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs, Outstanding
Number of RSUs, Granted	62,300
Number of RSUs, Vested and Released
Number of RSUs, Cancelled	(8,000)
Number of RSUs, Outstanding	54,300
Weighted Average Grant Date Fair Value, Outstanding | $ / shares
Weighted Average Grant Date Fair Value, Granted | $ / shares	1.84
Weighted Average Grant Date Fair Value, Vested and Released | $ / shares
Weighted Average Grant Date Fair Value, Cancelled | $ / shares	1.84
Weighted Average Grant Date Fair Value, Outstanding | $ / shares	$ 1.84

XML

Warrants (Narrative) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding	5,288,466	5,452,691	3,899,199	2,649,199
Exercise price	$ 5.13	$ 4.92	$ 6.76	$ 7.97
Warrant expiration date, start	Dec. 04, 2017
Warrant expiration date, end	Dec. 12, 2022
Average remaining contractual life of warrants outstanding	4 years 1 month 6 days
Probability of entering into a fundamental transaction	5.00%
Maximum [Member]
Class of Warrant or Right [Line Items]
Exercise price	$ 12.80
Minimum [Member]
Class of Warrant or Right [Line Items]
Exercise price	$ 3.00

XML

Warrants (Summary Of Changes In Warrants Outstanding During The Period) (Details) - $ / shares		6 Months Ended
	Jun. 12, 2017	Jun. 30, 2017	Jun. 30, 2016
Warrants [Abstract]
Number of warrants, Outstanding		5,452,691	2,649,199
Weigted average exercise price, Outstanding		$ 4.92	$ 7.97
Number of warrants, issued	1,515,152	1,696,970	1,250,000
Weighted average exercise price, Issued		$ 4.01	$ 4.20
Number of warrants, Exercised		(1,861,195)
Weighted average exercise price, Exercised		$ 3.51
Number of warrants, Expired
Weighted average exercise price, Expired
Number of warrants, Outstanding		5,288,466	3,899,199
Weigted average exercise price, Outstanding		$ 5.13	$ 6.76

XML

Warrants (Schedule Of Fair Value Of Warrants Issued) (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Class of Warrant or Right [Line Items]
Fair value	$ 9,796,591	$ 1,573,366
December 2012 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	7,316	49
July 2013 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	183,108	2,060
October 2013 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	241,999	3,708
January 2014 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	303,762	714
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	2,362,538	260,500
November 2015 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	5,573	13,542
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	1,219,172	358,945
March 2016 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value		21,320
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	1,795,810	854,640
September 2016 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value		$ 57,888
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	3,289,759
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	$ 387,554

XML

Warrants (Summary Of Shares Indexed To The Warrants) (Details) - shares	Jun. 30, 2017	Dec. 31, 2016
Class of Warrant or Right [Line Items]
Number of shares indexed	5,288,466	5,452,691
December 2012 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	17,430	17,430
July 2013 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	200,000	200,000
October 2013 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	231,732	231,732
January 2014 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	476,193	476,193
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	1,250,001	1,250,001
November 2015 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	3,334	83,335
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	607,806	1,171,875
March 2016 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed		78,125
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	805,000	1,800,000
September 2016 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed		144,000
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	1,515,152
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	181,818

XML

Warrants (Schedule Of Assumptions Used In Calculating Fair Value Of Warrants) (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Class of Warrant or Right [Line Items]
Trading market prices	$ 2.86	$ 1.40
Estimated future volatility	104.00%	104.00%
Dividend
Minimum [Member]
Class of Warrant or Right [Line Items]
Estimated future risk-free rate	1.23%	1.06%
Equivalent volatility	106.00%	51.00%
Equivalent risk-free rate	0.87%	0.59%
Maximum [Member]
Class of Warrant or Right [Line Items]
Estimated future risk-free rate	2.31%	2.44%
Equivalent volatility	129.00%	60.00%
Equivalent risk-free rate	1.48%	1.25%

XML

Warrants (Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	$ 5,521,249	$ 2,118,090	$ (12,168,331)	$ 2,974,045
Expired Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants		771		2,590
December 2012 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	35,454	5,911	(7,267)	7,278
July 2013 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	368,332	63,246	(181,048)	93,900
October 2013 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	438,919	103,166	(238,291)	129,607
January 2014 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	778,762	92,428	(303,048)	117,714
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	2,017,712	875,913	(2,102,038)	1,204,626
November 2015 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	(96,560)	58,276	(368,385)	80,160
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	702,730	860,121	(3,229,781)	1,252,266
March 2016 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	(82,867)	$ 58,258	(351,899)	$ 85,904
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	928,592		(5,313,599)
September 2016 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants			(503,150)
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	383,409		383,409
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain (loss) on fair value of warrants	$ 46,766		$ 46,766

XML

Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Provision for income taxes
Operating loss carry-forward	119,618,000		$ 119,618,000		$ 111,605,000
Net operating loss carry-forwards expiration			Dec. 31, 2037
Federal And State [Member]
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 0	$ 0	$ 0	$ 0

XML

Income Taxes (Schedule Of Deferred Tax Assets And Valuation Allowance) (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Net Operating Loss Carryforwards	$ 46,651,000	$ 43,526,000
Stock Compensation Expense	2,109,000	1,968,000
Book tax differences on assets and liabilities	410,000	547,000
Valuation Allowance	(49,170,000)	(46,041,000)
Net Deferred Tax Assets

XML

Commitments And Contingencies (Narrative) (Details)					3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 20, 2015 ft²	Jul. 26, 2014 ft²	Jun. 07, 2013 ft²	Jun. 22, 2009 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2009 USD ($)
Commitments And Contingencies [Line Items]
Estimated cost to complete contracts					$ 8,500,000		$ 8,500,000
License Costs									$ 100,000
One-time milestone payment				$ 1,000,000
Employer matching contribution							100.00%
Maximum percentage of employee's gross pay							3.00%
Employer matching contribution on deferral							50.00%
Percentage of employee's gross pay							2.00%
Expense related to matching contribution					34,606	$ 31,587	$ 71,083	$ 63,089
Maximum [Member]
Commitments And Contingencies [Line Items]
Contract term, months							36 months
Minimum [Member]
Commitments And Contingencies [Line Items]
Contract term, months							2 months
Current Laboratory Lease [Member]
Commitments And Contingencies [Line Items]
Lease term							5 years
Size of lease space | ft²	2,552
Rent expense					15,771	15,312	$ 31,543	30,624
Office Space Rental [Member]
Commitments And Contingencies [Line Items]
Lease term							22 months
Renewed lease term							1 year
Size of lease space | ft²			5,466
Additional office space | ft²		1,727
Rent expense					$ 50,898	$ 51,301	$ 101,796	$ 102,603

XML

Commitments and Contingencies (Schedule Of Future Rental Payments) (Details)	Jun. 30, 2017 USD ($)
Commitments And Contingencies [Abstract]
2017	$ 137,360
2018	279,274
2019	176,080
2020	34,468
Total	$ 627,182

XML

Fair Value Measurements (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	$ 17,986,160	$ 8,737,107
Warrant Liabilities	9,796,591	1,573,366
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	14,770,830	4,031,170
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		720,197
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	3,215,330	3,985,740
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	17,986,160	8,737,107
Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	14,770,830	4,031,170
Level 2 [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		720,197
Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	3,215,330	3,985,740
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant Liabilities	$ 9,796,591	$ 1,573,366

XML

Fair Value Measurements (Reconciliation Of Changes In The Fair Value Of Liabilities) (Details) - Warrant Liabilities [Member] - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 1,573,366	$ 2,739,163
Additions	4,107,488	2,575,860
Unrealized (gains) losses, net	12,168,331	(2,974,045)
Transfers out of level 3	(8,052,594)
Balance	$ 9,796,591	$ 2,340,978