Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 44,169	$ 46,668
Short-term investments	390
Accounts receivable, net	5,729	8,610
Inventory, net	7,113	6,281
Prepaid expenses and other current assets	5,518	5,756
Total current assets	62,919	67,315
Goodwill	20,123	20,123
Intangible assets, net	12,933	13,321
Right-of-use lease assets	275	318
Property and equipment, net	88	113
Restricted cash	40	40
Total assets	96,378	101,230
Current liabilities:
Accounts payable	2,789	2,278
Accrued expenses	4,297	4,866
Accrued interest expense on deferred royalty obligation, current portion	5,957	5,163
Deferred revenue	2,849	2,849
Paycheck Protection Program loan		2,325
Lease liabilities, current portion	156	154
Total current liabilities	16,048	17,635
Deferred royalty obligation, net	124,519	124,503
Accrued interest expense on deferred royalty obligation, less current portion	25,262	24,590
Lease liabilities, less current portion	120	164
Fair value of contingent value rights	923	1,076
Total liabilities	166,872	167,968
Commitments and contingencies (Note 8)
Stockholders’ deficit:
Common Stock, $0.0001 par value; 100,000,000 shares authorized, 25,663,667 and 26,783,544 shares issued and outstanding at March 31, 2022 and December 31, 2021, respectively	3	3
Additional paid-in capital	982,687	986,445
Accumulated deficit	(1,057,090)	(1,057,092)
Total stockholders’ deficit	(70,494)	(66,738)
Total liabilities and stockholders’ deficit	96,378	101,230
Series C-1 Convertible Preferred Stock
Stockholders’ deficit:
Series C-12 Convertible Preferred Stock, $0.0001 par value; 11,000 shares authorized, 3,906 shares issued and outstanding at March 31, 2022 and December 31, 2021; and liquidation preference of $3,906 at March 31, 2022 and December 31, 2021	$ 3,906	$ 3,906