Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 36,917	$ 20,079
Marketable securities	2,987	51,199
Restricted cash	584	584
Prepaid expenses and other current assets	2,069	4,240
Total current assets	42,557	76,102
Property and equipment, net		2,269
Equity method investment		7,428
Other assets	2,483	2,744
Total assets	45,040	88,543
Current liabilities:
Accounts payable, accrued expenses and other	4,940	13,677
Deferred rent		1,118
Total current liabilities	4,940	14,795
Note payable, net of discount and current portion		14,873
Other long-term liabilities	56	56
Total liabilities	4,996	29,724
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value: 10,000 shares authorized at June 30, 2019 and December 31, 2018; no shares issued or outstanding at June 30, 2019 or December 31, 2018
Common stock, $0.01 par value: 30,000 shares authorized at June 30, 2019 and December 31, 2018; 13,349 and 13,343 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	1,334	1,334
Additional paid-in capital	581,875	580,771
Accumulated other comprehensive loss		(9)
Accumulated deficit	(543,165)	(523,277)
Total stockholders’ equity	40,044	58,819
Total liabilities and stockholders’ equity	$ 45,040	$ 88,543