Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows used in operating activities
Net loss	$ (42,593)	$ (29,365)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	288	200
Non-cash interest expense (debt discount and deferred costs)	2,191	909
Loss on extinguishment of debt	4,546
Change in fair value of derivative liabilities	(10,311)	(2,072)
Stock-based compensation expense	1,869	2,025
Provision for inventory obsolescence and net realizable value	12,551	56
Loss on disposal of assets	181
Changes in assets and liabilities:
Accounts receivable	9,384	4,730
Prepaid expenses and other current assets	(1,229)	(713)
Inventory	(617)	(4,195)
Deposits and other assets	(57)	3
Accounts payable	(1,795)	(1,133)
Accrued expenses and other current liabilities	(2,305)	(97)
Deferred revenue		(628)
Accrued interest	(1,151)	128
Net cash used in operating activities	(29,048)	(30,152)
Cash flows used in investing activities
Capital expenditures	(100)	(392)
Payments on right of use liability, building		(98)
Net cash used in investing activities	(100)	(490)
Cash flows used in financing activities
Proceeds from issuance of common stock	117
Common stock issuance costs	(204)
Proceeds from exercise of stock options and stock warrants	498	23
Repayment of term loans	(48,396)	(2,499)
Net cash used in financing activities	(47,985)	(2,476)
Net decrease in cash, cash equivalents, and restricted cash	(77,133)	(33,118)
Cash, cash equivalents and restricted cash at beginning of period	95,938	136,793
Cash, cash equivalents and restricted cash at ending of period	18,805	103,675
Supplemental disclosure of cash flow information
Cash paid during the period for interest	3,344	$ 1,705
Supplemental disclosure of non-cash investing and financing activities
Property and equipment purchases included in accounts payable and accrued expenses	$ 48