CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income (loss)	$ 3,543	$ (7,367)
Adjustments to reconcile net income (loss) to net cash generated from (used in) operations:
Stock-based compensation	5,101	4,520
Accretion of interest expense	1,562	2,196
Amortization of debt financing costs	16	20
Depreciation and amortization of property and equipment	72	127
Changes in operating assets and liabilities:
Trade receivables	(2,015)	(2,611)
Inventory	(825)	703
Prepaid expenses and other current assets	(679)	261
Other assets	0	(11)
Accounts payable	2,984	(146)
Accrued clinical expenses	604	273
Other accrued liabilities	3,617	956
Deferred revenue	(158)	46
Net cash provided by (used in) operating activities	13,822	(1,033)
Cash flows from investing activities:
Purchases of property and equipment	(119)	(34)
Cash used in investing activities	(119)	(34)
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of options and warrants, net of issuance costs	4,073	19,712
Payments related to long-term obligation	(10,346)	(6,443)
Net cash provided by (used in) financing activities	(6,273)	13,269
Net increase in cash and cash equivalents	7,430	12,202
Cash and cash equivalents, at beginning of period	40,435	24,248
Cash and cash equivalents, at end of period	$ 47,865	$ 36,450