Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (11,488)	$ (14,344)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense	2,189	2,136
Stock-based compensation expense	1,611	2,106
Unrealized foreign exchange loss	(15)	229
Non-cash lease expense	579	584
Provision for bad debts on trade receivables	102	(19)
Loss on extinguishment of debt	0	1,085
Non-cash interest expense	352	51
Changes in operating assets and liabilities:
Accounts receivable	2,778	2,013
Royalty and licensing receivable	(6,032)	(23)
Inventories	(1,107)	(1,104)
Prepaid expenses and other assets	592	(324)
Accounts payable, accrued expenses and other liabilities	(2,717)	(564)
Advance on research and development	819	0
Net cash used in operating activities	(12,337)	(8,178)
Cash flows from investing activities:
Acquisition of property and equipment	(2,588)	(1,298)
Maturity of investments	0	7,250
Net cash (used in) provided by investing activities	(2,588)	5,952
Cash flows from financing activities:
Proceeds from exercise of common stock options	0	121
Debt issuance costs	(10)	(685)
Loss on extinguishment of debt	0	(919)
Proceeds from issuance of debt	4,720	20,000
Amortization/accretion on investments	0	(4)
Payments on long-term debt	0	(15,000)
Net proceeds from issuance of common stock	2,024	3,000
Net cash provided by financing activities	6,734	6,517
Foreign exchange effect on cash and cash equivalents	(35)	(12)
(Decrease) increase in cash, cash equivalents and restricted cash	(8,226)	4,279
Cash, cash equivalents and restricted cash beginning of period	26,856	16,842
Cash, cash equivalents and restricted cash end of period	18,630	21,121
Supplemental information:
Cash paid for interest	691	1,425
Non cash investing and financing activities:
Operating leases right-of-use assets obtained in exchange for lease obligations	$ 0	$ 6,988