Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities:
Net Loss	$ (44,785)	$ (19,784)	$ (12,318)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	3,198	2,459	1,669
Stock issued for milestone payments	1,350	0	0
Stock issued for exclusive channel collaboration agreement	3,000	0	0
Stock issued for license agreement	0	0	425
Change in fair value of warrant liabilities	3,811	(620)	0
Depreciation and amortization	72	20	43
Provision for uncollectible note and interest receivables	0	0	763
Loss on sale of equipment	0	0	58
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(7,971)	43	855
Deposits and other assets	(8)	(2)	33
Accounts payable	3,417	854	(253)
Accrued expenses	(1,001)	416	885
Accrued employee benefits	(261)	535	0
Deferred rent	288	0	0
Impairment loss on equipment	0	0	121
Net Cash Used In Operating Activities	(38,890)	(16,079)	(7,719)
Cash Flows From Investing Activities:
Purchases of property and equipment	(501)	(48)	(36)
Net Cash Used In Investing Activities	(501)	(48)	(36)
Cash Flows From Financing Activities:
Proceeds from issuance of common stock	46,000	20,668	13,224
Cash paid as direct offering costs	(3,357)	(1,645)	(1,031)
Proceeds from issuance of common stock for stock option exercises	41	4	232
Cash received from issuance of stock to non-controlling interest	0	0	1
Net Cash Provided By Financing Activities	42,684	19,027	12,426
Net increase in cash	3,293	2,900	4,671
Cash at beginning of year	17,525	14,625	9,954
Cash at end of year	20,818	17,525	14,625
Supplemental disclosures of cash flow information:
Cash paid for interest	0	0	0
Cash paid for taxes	$ 0	$ 0	$ 0