CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net income (loss)	$ 5,422	$ (23,123)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	111	292
Non-cash interest expense	26	67
Stock-based compensation expense	3,351	1,895
Change in fair value of warrant liability	(38)	(3,186)
Loss on extinguishment of debt	221	0
Gain on sale of equipment	(14)	0
Changes in operating assets and liabilities, excluding impact of acquisition:
Prepaid expenses and other assets	62	(311)
Restricted cash	(10)	0
Accounts payable	(648)	(179)
Accrued expenses and other liabilities	(1,189)	(568)
Deferred revenue	844	(35)
Net cash provided by (used in) operating activities	8,138	(25,148)
Investing activities
Cash acquired in the acquisition	136	0
Sales (purchases) of property and equipment, net	283	(286)
Net cash provided by (used in) investing activities	419	(286)
Financing activities
Proceeds from issuance of common stock and common stock warrants, net of offering costs	0	12,675
Payments on notes payable	(14,124)	0
Proceeds from notes payable	0	5,000
Proceeds from exercise of common stock options and warrants	204	62
Net cash (used in) provided by financing activities	(13,920)	17,737
Net decrease in cash and cash equivalents	(5,363)	(7,697)
Cash and cash equivalents at beginning of period	36,079	54,059
Cash and cash equivalents at end of period	30,716	46,362
Supplemental non-cash investing and financing activities
Common stock issued in connection with the Acquisition	13,525	0
Fair value of assets acquired in the acquisition, excluding cash and cash equivalents	48,568	0
Fair value of liabilities assumed in the acquisition	13,279	0
Issuance of warrants for common stock	0	328
Supplemental cash flow information
Cash paid for interest	$ 663	$ 644