Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS USED IN OPERATING ACTIVITIES:
Net loss	$ (42,760)	$ (61,555)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	633	671
Amortization of discount on marketable securities, net	(65)	(180)
Amortization of debt discount and debt issuance costs	3,750	3,278
Impairment loss on operating lease right of use assets	339
Stock-based compensation	6,114	7,549
Changes in operating assets and liabilities:
Inventory	564	(1,072)
Accounts receivable, net	(3,992)	(3,607)
Prepaid expenses	1,470	(1,254)
Other current assets	446	(50)
Operating lease right of use assets	500
Other long-term assets	43	43
Accounts payable	5,654	610
Accrued expenses and other current liabilities	(6,571)	(14,641)
Lease liability, operating leases	(565)
Other non-current liabilities	(24)	(24)
Net cash used in operating activities	(34,464)	(70,232)
CASH FLOWS PROVIDED BY INVESTING ACTIVITIES:
Purchases of property and equipment	0	(61)
Purchases of marketable securities	0	(500)
Sales and maturities of marketable securities	45,000	0
Net cash provided by (used in) investing activities	45,000	(561)
CASH FLOWS PROVIDED BY FINANCING ACTIVITIES:
Proceeds from exercise of stock options and warrant exercises	622	6,576
Proceeds from issuance of shares under employee stock purchase plan	1,027	1,741
Net cash provided by financing activities	1,649	8,317
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	12,185	(62,476)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT BEGINNING OF YEAR	59,881	118,619
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT END OF PERIOD	72,066	56,143
SUPPLEMENTAL DISCLOSURES:
Cash paid for interest	4,575	0
Property and equipment purchases in accrued expenses at period end	0	287
Receivable due from stock options exercises	1,895	$ 0
Cash paid for amounts included in the measurement of operating lease liabilities	685
Right of use assets obtained in exchange for operating lease liability	$ 8,289