4.	Convertible Notes Payable

Convertible notes payable consisted of the following:

	June 30,			December 31,
	2017			2016
Current maturities:
Convertible note payable issued during 2014 to Ligand pursuant to the Master License Agreement with a 5% annual interest rate, due during 2016 (amended in January 2016 to a 2.5% annual interest rate with maturity extended to 2017, and subsequently amended in May 2017 with maturity extended to May 21, 2018)	$	1,955,139		$	1,955,139
Conversion payoff value		2,014,472			1,990,032
Discount on notes payable, current		(919,184	)		(675,589	)
Convertible notes payable, current (net of discount)	$	3,050,427		$	3,269,582

Pursuant to the Loan and Security Agreement, among other things, Ligand provided the Company with loans in the aggregate amount of $2.5 million. Up until January 21, 2016, the principal amount outstanding under the loans accrued interest at a fixed per annum rate equal to the lesser of 5.0% or the maximum interest rate permitted by law. Effective as of January 22, 2016, the principal amount outstanding under the loans accrue interest at a fixed per annum rate equal to the lesser of 2.5% or the maximum interest rate permitted by law. In the event the Company defaults under the loans, the loans will accrue interest at a fixed per annum rate equal to the lesser of 8% or the maximum interest rate permitted by law. The loans are evidenced by the Ligand Note. Pursuant to the terms of the Loan and Security Agreement and the Ligand Note, the loans will become due and payable upon the written demand of Ligand at any time after the earlier to occur of an event of default under the Loan and Security Agreement or the Ligand Note, or May 21, 2018 (the “Maturity Date”), unless the loans are repaid in cash or converted into equity prior to such time. In addition, under the Loan and Security Agreement, the Company may not declare or pay dividends in respect of its common stock without Ligand’s prior written consent.

Additionally, pursuant to the terms of the Loan and Security Agreement, upon the consummation of the Company’s first bona fide capital financing transaction occurring after January 22, 2016, but prior to the Maturity Date, with aggregate net proceeds to the Company of at least $2,000,000 (the “Next Financing”), the Company was required to repay $1,500,000 of the Ligand Note obligation to Ligand, with at least $300,000 of such payment to be paid in cash (with any greater cash amount determined by the Company in its sole and absolute discretion), and the balance of the $1,500,000 payment (the “Balance”) to be paid in the form of such number of shares of the Company’s equity securities that are issued in the Next Financing as is equal to the quotient obtained by dividing the Balance by the lesser of (1) the lowest price per share paid by investors in the Next Financing (the “Financing Price”), and (2) $8.00 (subject to adjustment for stock dividends, splits, combinations or similar transactions). Each $1.00 of the $1,500,000 payment reduced the amount of accrued and unpaid interest and then unpaid principal amount of the loans under the Ligand Note by $0.50.

As a result of an amendment to the Loan and Security Agreement entered into on January 22, 2016, which amended the conversion terms of the Ligand Note, beginning with the quarter ended March 31, 2016, management adopted the Black-Scholes-Merton option valuation model for the Ligand Note, resulting in a debt modification adjustment of $575,685 to the debt conversion feature liability, offset with an adjustment recorded to the Ligand Note discount and conversion payoff value.

On April 13, 2016, the Company completed an underwritten public offering of its common stock and warrants to purchase shares of its common stock (the “Offering”) resulting in net proceeds of $7,754,286, after deducting underwriting discounts, commissions and other offering expenses of $1,631,964. The Offering constituted a Next Financing under the Loan and Security Agreement; therefore, the Company repaid $1,500,000 of the Ligand Note with $300,000 paid in cash and $1,200,000 paid in the form of 960,000 shares of its common stock (the “Ligand Shares”) and a warrant to purchase up to 960,000 shares of Company’s common stock (the “Ligand Warrant”). The Ligand Warrant has an exercise price of $1.50 per share of common stock, was immediately exercisable upon issuance and will expire on April 13, 2021.

On May 8, 2017, the Company entered into the Third Loan Amendment, which, (1) extended the maturity date of the Loans from May 21, 2017 to May 21, 2018, and (2) provided that the Company will be required to make the $200,000 Required Repayment. The Required Repayment will be applied, first, to accrued and unpaid interest on the Loans and, second, to the unpaid principal amount of the Loans. Each $1.00 of value of the Required Repayment will reduce the amount of accrued and unpaid interest and then unpaid principal amount on the Loans by $0.50. As a result of the Third Loan Amendment, the Company recorded a debt modification adjustment of $1.0 million to the debt conversion feature liability primarily due to the longer expected term, offset with an adjustment recorded to the Ligand Note discount.

In addition, the Company may repay any portion of the outstanding principal amount of the loans under the Ligand Note, plus accrued and previously unpaid interest thereon, by delivering a notice to Ligand (the “Additional Repayment Notice”), specifying the amount that the Company wishes to repay (the “Additional Payment Amount”). Ligand will have five days to elect to receive the Additional Payment Amount in cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock. If Ligand does not make an election within such five-day period, the form of the Additional Payment Amount will be at the Company’s sole election and discretion, subject to the number of shares of common stock being reduced to the extent that the issuance of shares would increase Ligand’s beneficial ownership of the Company’s common stock to greater than 49.9%. To the extent that any portion of an Additional Payment Amount will be paid in the form of shares of the Company’s common stock, the number of shares issuable will be equal to the quotient obtained by dividing the portion of the Additional Payment Amount that will be paid in shares by the lesser of (1) (a) if the Company delivers the Additional Repayment Notice within 180 days of the closing of the Next Financing, the Financing Price, or (b) if the Company delivers the Additional Repayment Notice 180 days or more after the closing of the Next Financing, the volume weighted average closing price of the Company’s common stock for the 30 days prior to the date the Company delivers the Additional Repayment Notice, and (2) $8.00 (subject to adjustment for stock dividends, splits, combinations or similar transactions). Each $1.00 of any Additional Repayment Amount will reduce the amount of accrued and unpaid interest and then unpaid principal amount under the Ligand Note by $0.50.

Following the Maturity Date, Ligand may demand repayment of the loans under the Ligand Note in full. If (1) the Ligand Note is not repaid in full prior to the Maturity Date and Ligand demands repayment, or (2) the Company wishes to repay the full amount owed under the Ligand Note prior to the Maturity Date, the Company will be obligated to repay to Ligand an amount equal to 200% of the aggregate of the outstanding principal amount of the loans under the Ligand Note and of all accrued and unpaid interest thereon (the “Remaining Balance”).

In either case, the Company may, at its sole election and discretion, elect to pay the Remaining Balance solely in cash. If the Company does not elect to repay the Remaining Balance in cash, the form of payment and mix of cash and shares of the Company’s common stock will be at Ligand’s sole election and discretion. To the extent that any portion of the Remaining Balance will be paid in the form of shares of the Company’s common stock, the number of shares issuable will be equal to the quotient obtained by dividing the portion of the Remaining Balance that will be paid in shares by the lesser of (1) the volume weighted average closing price of the Company’s common stock for the 30 days prior to the date of Ligand’s demand for repayment or the date of the Company’s prepayment of the Remaining Balance in full, and (2) $8.00 (subject to adjustment for stock dividends, splits, combinations or similar transactions).

In connection with the Loan and Security Agreement, the Company also granted Ligand a continuing security interest in all of its right, title and interest in and to its assets as collateral for the full, prompt, complete and final payment and performance when due of all obligations under the Loan and Security Agreement and the Ligand Note.

During the three and six months ended June 30, 2017, the Company recorded $24,439 and $48,878 of interest expense, respectively, $336,656 and $767,883 of amortization of debt discount, respectively, and $570,676 and $848,374 as other income related to the change in the fair value of the debt conversion feature liability, respectively.

During the three and six months ended June 30, 2016, the Company recorded $25,423 and $56,673 of interest expense, respectively, $524,977 and $925,634 of amortization of debt discount, respectively, and $412,050 and $508,597 as other income related to the decrease in the fair value of the debt conversion feature liability, respectively.