CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities
Net loss	$ (9,179)	$ (16,976)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	553	435
Stock-based compensation	4,912	4,340
Amortization of discounts and premiums on marketable securities	(147)	43
Intangible asset amortization	886	5,885
Other non-cash adjustments, net	210	226
Changes in operating assets and liabilities:
Accounts receivable	(756)	2,070
Prepaid expenses and other assets	(3,921)	(4,580)
Inventory	(7)	(263)
Accounts payable and accrued liabilities	2,646	2,381
Accrued government and other rebates	(2,814)	(1,722)
Net cash used in operating activities	(7,617)	(8,161)
Cash flows from investing activities
Purchases of property and equipment	(1,102)	(111)
Purchases of marketable securities	(81,171)	(103,993)
Maturities of marketable securities	59,277	83,577
Net cash used in investing activities	(22,996)	(20,527)
Cash flows from financing activities
Proceeds from the exercise of stock options	4,402	1,039
Net cash provided by financing activities	4,402	1,039
Effect of foreign currencies on cash and cash equivalents	17
Net decrease in cash and cash equivalents	(26,194)	(27,649)
Cash and cash equivalents
Beginning of period	40,426	50,843
End of period	$ 14,232	$ 23,194