CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 6,494	$ 21,572
Short-term investments	89,268	69,552
Accounts receivable, net	14,305	7,549
Inventory	6,844	4,097
Prepaid expenses and other current assets	3,032	1,290
Restricted cash	80	80
Total current assets	120,023	104,140
Property and equipment, net	7,593	2,154
Intangible asset, net	6,567	10,218
Deposits and other assets	188	149
Total assets	134,371	116,661
Current liabilities:
Accounts payable	2,967	3,626
Accrued liabilities	13,911	7,793
Long-term debt, current portion		8,931
Deferred rent	60	12
Total current liabilities	16,938	20,362
Long-term debt, less current portion		765
Stock warrant liability		105
Other liabilities	159	238
Total liabilities	17,097	21,470
Commitments and contingencies (see Note 10)
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000 shares and no shares authorized at December 31, 2016 and 2015, respectively; no shares issued and outstanding at December 31, 2016 and 2015
Common stock, $0.001 par value; 150,000 shares authorized at December 31, 2016 and 2015; 33,971 and 32,209 shares issued and 33,943 and 32,181 shares outstanding at December 31, 2016 and 2015, respectively	34	32
Additional paid-in capital	308,815	291,853
Accumulated other comprehensive income	648	51
Accumulated deficit	(192,091)	(196,613)
Less treasury stock (28 shares as of December 31, 2016 and 2015)	(132)	(132)
Total stockholders' equity	117,274	95,191
Total liabilities and stockholders' equity	$ 134,371	$ 116,661