STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income (loss)	$ 8,140	$ (6,408)	$ (31,383)
Adjustments to reconcile net income (loss) to net cash generated from (used in) operations:
Stock-based compensation	7,058	6,013	5,201
Accretion of interest expense	1,929	2,848	3,678
Amortization of debt financing costs	21	22	29
Depreciation and amortization of property and equipment	87	155	141
Changes in operating assets and liabilities:
Trade receivables	(3,639)	(2,887)	(1,906)
Inventory	(682)	815	249
Prepaid expenses and other current assets	(1,322)	799	(531)
Other assets	0	(7)	10
Accounts payable	965	(561)	(495)
Accrued clinical expenses	296	835	(2,952)
Other accrued liabilities	5,696	1,381	575
Deferred revenue	(158)	125	8
Net cash provided by (used in) operating activities	18,391	3,130	(27,376)
Cash flows from investing activities:
Purchases of property and equipment	(194)	(17)	(174)
Cash used in investing activities	(194)	(17)	(174)
Cash flows from financing activities:
Proceeds from exercise of warrants, net of issuance costs	0	17,088	0
Proceeds from exercise of stock options, net of issuance costs	7,683	5,193	1,777
Payments related to long-term obligation	(14,779)	(9,207)	(4,856)
Net cash provided by (used in) financing activities	(7,096)	13,074	(3,079)
Net increase (decrease) in cash and cash equivalents	11,101	16,187	(30,629)
Cash and cash equivalents, at beginning of period	40,435	24,248	54,877
Cash and cash equivalents, at end of period	$ 51,536	$ 40,435	$ 24,248