Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 57,545	$ 21,312
Cash held in escrow		14,979
Short-term investments	39,538	19,421
Accounts receivable (net of allowances of $30 at March 31, 2021 and $72 at December 31, 2020)	993	940
Inventories, net	1,955	1,864
Prepaid expenses and other current assets	4,780	4,545
Total current assets	104,811	63,061
Property and equipment, net	224	251
Operating lease right-of-use assets	4,440	4,749
Goodwill	6,169	6,169
Long-term investments		1,000
Long-term restricted investments	150	150
Other long-term assets	261	261
Total assets	116,055	75,641
Current liabilities:
Accounts payable	2,150	1,678
Accrued liabilities	4,094	5,801
Contract research liabilities	384	545
Deferred revenue, current portion	373
Term loan, current portion, net	2,895	884
Operating lease liabilities, current portion	1,808	1,795
Total current liabilities	11,704	10,703
Deferred revenue, non-current portion	812	812
Operating lease liabilities, non-current portion	2,881	3,202
Term loan, non-current portion, net	18,062	19,936
Other long-term liabilities	873	873
Commitments and contingencies
Stockholders’ equity:
Common stock	23	20
Additional paid-in capital	581,632	529,884
Accumulated other comprehensive loss	(14)	(5)
Accumulated deficit	(499,918)	(489,784)
Stockholders’ equity	81,723	40,115
Total liabilities and stockholders’ equity	$ 116,055	$ 75,641