Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 5,404	$ 3,583
Short-term investments	19,600	25,457
Accounts receivable (net of allowances of $73 at December 31, 2016 and $161 at December 31, 2015)	1,154	2,222
Inventories	3,782	3,917
Prepaid expenses and other current assets	2,486	3,142
Total current assets	32,426	38,321
Property and equipment, net	1,297	1,566
Goodwill	6,399	6,399
Long-term restricted investments	150	250
Other long-term assets	236	236
Total assets	40,508	46,772
Current liabilities:
Accounts payable	2,086	1,286
Accrued liabilities	5,060	4,970
Contract research liabilities	783	575
Deferred revenue, current portion	968	616
Term loan, current portion, net	19,853
Total current liabilities	28,750	7,447
Deferred revenue, non-current portion	1,879	2,269
Term loan, non-current portion, net		19,684
Other long-term liabilities	1,541	2,489
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value: 10,000 shares authorized; none issued and outstanding
Common stock, $0.0001 par value: 200,000 shares authorized; 141,297 and 121,839 shares issued and outstanding at December 31, 2016 and 2015, respectively	14	12
Additional paid-in capital	448,404	420,453
Accumulated other comprehensive income (loss)	(3)	(14)
Accumulated deficit	(440,077)	(405,568)
Stockholders’ equity	8,338	14,883
Total liabilities and stockholders’ equity	$ 40,508	$ 46,772