Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (30,385)	$ (16,324)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation, amortization and accretion	706	908
Stock-based compensation expense	1,943	1,267
Loss on extinguishment of debt	825
Loss on foreign currency translation	2,984	1,545
Interest on note payable to related party	1,122	714
Change in fair value of warrant liability		(6,629)
Write-off of inventory	602
Other, net	110
Changes in operating assets and liabilities:
Accounts receivable, net	1,128	(136)
Receivable from Sanofi		30,557
Inventory	(1,836)	(1,367)
Deferred costs from commercial product sales		(163)
Prepaid expenses and other current assets	656	856
Other assets	38	39
Accounts payable	(2,008)	(1,665)
Accrued expenses and other current liabilities	2,675	1,077
Deferred revenue		(1,575)
Deferred payments from collaboration	(63)	(63)
Recognized loss on purchase commitments	(147)	(534)
Net cash (used in) provided by operating activities	(21,650)	8,507
CASH FLOWS FROM INVESTING ACTIVITIES:
Net proceeds from sale of asset held for sale		16,651
Net cash provided by investing activities		16,651
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of employment taxes related to vested restricted stock units	(81)	(75)
Proceeds from issuance of common stock pursuant to at-the-market issuance	634
Issuance cost of at-the-market transactions	(25)
Net cash provided by (used in) financing activities	528	(75)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH	(21,122)	25,083
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD	48,355	22,895
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD	27,233	47,978
SUPPLEMENTAL CASH FLOWS DISCLOSURES:
Interest paid in cash, net of amounts capitalized	1,860	$ 2,550
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Payment of note obligations through common stock issuance	9,407
Payment of note payable to related party through common stock issuance	8,160
Accrued but unpaid debt issuance costs related to note payable to related party	$ 75