BALANCE SHEETS - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 61,031,000	$ 13,406,000
Restricted cash	20,000	20,000
Other receivable	233,000
Prepaid expenses and other assets	1,344,000	340,000
Total current assets	62,628,000	13,766,000
Property and equipment, net	355,000	302,000
Other assets	43,000	31,000
Total assets	63,026,000	14,099,000
Current liabilities:
Convertible promissory notes, net of discount		12,095,000
Derivative liability		3,028,000
Current portion of long-term debt		761,000
Accounts payable	1,806,000	430,000
Accrued expenses	2,771,000	1,281,000
Total current liabilities	4,577,000	17,595,000
Preferred stock warrant liability		1,656,000
Deferred rent	22,000	5,000
Long-term debt	7,500,000	2,625,000
Total liabilities	12,099,000	21,881,000
Commitments and contingencies (Note 7)
Redeemable convertible preferred stock, $0.001 par value; zero and 13,321,350 shares authorized at December 31, 2018 and 2017, respectively; zero and 9,131,999 shares issued and outstanding at December 31, 2018 and 2017, respectively.		89,633,543
Stockholders’ equity (deficit):
Preferred stock, $0.001 par value; 10,000,000 and zero shares authorized at December 31, 2018 and 2017, respectively; zero shares issued and outstanding at December 31, 2018 and 2017, respectively
Common stock, $0.001 par value; 200,000,000 and 14,918,087 shares authorized at December 31, 2018 and 2017, respectively; 24,528,242 shares issued and 24,498,275 shares outstanding at December 31, 2018; 775,755 shares issued and 745,788 shares outstanding at December 31, 2017	25,000	1,000
Treasury stock, at cost, 29,967 shares as of December 31, 2018 and 2017	(24,000)	(24,000)
Additional paid-in capital	173,837,000	1,672,000
Accumulated deficit	(122,911,000)	(99,065,000)
Total stockholders’ equity (deficit)	50,927,000	(97,416,000)
Total liabilities, redeemable convertible preferred stock, and stockholders' equity (deficit)	$ 63,026,000	$ 14,099,000