Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (86,975,000)	$ (117,333,000)	$ 125,664,000
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Depreciation, amortization and accretion	2,857,000	3,528,000	4,158,000
Stock-based compensation expense	6,857,000	4,847,000	5,135,000
Change in fair value of warrant liability		(5,488,000)	(5,369,000)
(Gain) Loss on foreign currency translation	(4,468,000)	13,641,000	(3,433,000)
(Gain) Loss on extinguishment of debt	765,000	1,611,000	(72,024,000)
Interest incurred through borrowings under Sanofi Loan Facility			4,478,000
Interest on note payable to related party	4,488,000	3,782,000	2,901,000
Series A warrant issuance cost			653,000
Other, net	(25,000)	100,000	19,000
(Gain) loss on sale, abandonment/disposal or impairment of property and equipment	(114,000)	203,000	1,259,000
Gain on purchase commitments	(10,000)	(215,000)	(2,265,000)
Write-off of inventory	2,212,000	2,971,000	0
Changes in operating assets and liabilities:
Accounts receivable, net	(1,339,000)	(2,487,000)	(302,000)
Receivable from Sanofi		30,557,000	(30,534,000)
Inventory	(3,152,000)	(3,297,000)	(2,331,000)
Deferred costs from commercial product sales		(96,000)	(309,000)
Deferred costs from collaboration			13,539,000
Prepaid expenses and other current assets	454,000	1,354,000	(346,000)
Other assets	200,000	188,000	361,000
Accounts payable	(1,605,000)	3,800,000	(12,118,000)
Accrued expenses and other current liabilities	2,249,000	2,932,000	348,000
Deferred revenue		(381,000)	3,419,000
Deferred payments from collaboration	46,814,000	(250,000)	(134,056,000)
Deferred sales from collaboration			(17,503,000)
Loss on purchase commitments	(6,939,000)	(4,745,000)	40,566,000
Net cash used in operating activities	(37,731,000)	(64,778,000)	(78,090,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(354,000)		(1,144,000)
Net proceeds from sale of asset held for sale		16,651,000
Proceeds from sale of property and equipment	120,000	24,000	17,000
Net cash provided by (used in) investing activities	(234,000)	16,675,000	(1,127,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from direct placement of common stock	28,000,000	61,000,000	50,000,000
Issuance cost associated with direct placement	(1,610,000)	(3,310,000)	(2,690,000)
Proceeds from issuance of common stock			893,000
Principal payments on facility financing obligation	(5,000,000)	(4,000,000)	(5,000,000)
Payment of employment taxes related to vested restricted stock units		(127,000)	(165,000)
Borrowings on note payable to related party		19,429,000
Proceeds from market price stock purchase plan	430,000
Other	7,000	24,000
Net cash provided by financing activities	61,294,000	73,563,000	43,038,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH	23,329,000	25,460,000	(36,179,000)
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD	48,355,000	22,895,000	59,074,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD	71,684,000	48,355,000	22,895,000
SUPPLEMENTAL CASH FLOWS DISCLOSURES:
Income taxes paid in cash	240,000	51,000
Interest paid in cash, net of amounts capitalized	3,759,000	7,728,000	8,991,000
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Payment of note obligations and interest through issuance of common stock	42,912,000	20,593,000
Payment of note payable to related party through issuance of common stock	8,160,000
Capitalization of interest on note payable to related party		10,716,000
Non-cash construction in progress and property and equipment			588,000
Reclassification of deferred payments from collaboration to Sanofi Loan Facility and loss share obligation			5,174,000
Reclassification of property and equipment to asset held for sale			$ 17,294,000
Reclassification of warrant liability to additional paid-in capital		1,880,000
Public Offering
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	40,000,000
Issuance costs	(2,538,000)
At-the-market Issuance
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	2,089,000	564,000
Issuance costs	$ (84,000)	$ (17,000)