CONDENSED BALANCE SHEETS - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 10,791,270	$ 11,453,133
Accounts receivable and unbilled receivable	122,281	167,755
Prepaid expenses	906,466	1,144,377
Total current assets	11,820,017	12,765,265
Property and equipment, net	252,053	1,304,433
Operating lease right-of-use assets	1,660,631	0
Other assets	135,262	102,798
Total Assets	13,867,963	14,172,496
Current liabilities:
Accounts payable	525,690	664,840
Accrued expenses	2,352,265	1,813,842
Operating lease liabilities	816,102	0
Deferred rent, current portion	0	486,636
Total current liabilities	3,694,057	2,965,318
Derivative financial instruments—warrants	18,287	32,315
Operating lease liabilities, net of current portion	1,307,384	0
Deferred rent, net of current portion	0	1,090,671
Total Liabilities	5,019,728	4,088,304
Commitments and contingencies (Note 8)
Stockholders’ equity
Preferred stock, $0.001 par value, 20,000,000 shares authorized; 277,100 designated as Series A Convertible Preferred Stock; 60,600 shares outstanding at June 30, 2019 and December 31, 2018 with liquidation preference of $606,000 at June 30, 2019 and December 31, 2018; 200,000 designated as Series C Convertible Preferred Stock; 0 shares outstanding at June 30, 2019 and December 31, 2018	60	60
Common stock, $0.0001 par value, 150,000,000 shares authorized; 5,441,390 and 3,831,880 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	7,997	7,742
Additional paid-in capital	210,706,090	202,267,605
Service receivables	(1,364,234)	0
Accumulated deficit	(200,501,678)	(192,191,215)
Total stockholders’ equity	8,848,235	10,084,192
Total liabilities and stockholders’ equity	$ 13,867,963	$ 14,172,496