CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 70,326	$ 90,943
Short-term investments	7,460	739
Prepaid expenses and other current assets	2,212	2,452
Total current assets	79,998	94,134
Property and equipment, net	2,186	2,265
Other assets	2,374	2,443
Total assets	84,558	98,842
Current liabilities:
Accounts payable	2,845	2,763
Accrued expenses	7,479	5,268
Total current liabilities	10,325	8,031
Other long-term liabilities	2,921	3,042
Total liabilities	13,245	11,073
Series A convertible preferred stock, $0.001 par value; 25,000,000 shares authorized, 30,000 shares issued and outstanding at March 31, 2020 and December 31, 2019	28,200	28,200
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock, $0.001 par value; 100,000,000 shares authorized, 86,761,236 issued and 86,732,035 outstanding at March 31, 2020 and 86,500,353 issued and 86,471,122 outstanding at December 31, 2019	87	87
Additional paid-in capital	306,124	295,056
Treasury stock at cost, 29,231 shares at March 31, 2020 and December 31, 2019
Accumulated other comprehensive income	28
Accumulated deficit	(263,126)	(235,574)
Total stockholders’ equity	43,113	59,569
Total liabilities and stockholders’ equity	$ 84,558	$ 98,842