Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
OPERATING ACTIVITIES:
Net loss	$ (16,014)	$ (18,106)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	95	128
Provision for sales returns	209	5
Amortization of deferred financing costs and debt discounts	609	217
Stock-based compensation	4,119	341
Other	66	81
Changes in assets and liabilities:
Accounts receivable	(2,972)	(879)
Inventory	(817)	2,076
Prepaid and other current assets	(1,320)	(1,374)
Accounts payable, accrued and other liabilities	(264)	(257)
Cash used in operating activities	(16,289)	(17,768)
INVESTING ACTIVITIES:
Purchase of fixed assets	(24)	(25)
Proceeds on sale of fixed assets	3	35
Cash provided by (used in) investing activities	(21)	10
FINANCING ACTIVITIES:
Proceeds from exercise of stock options		18
Proceeds from issuance of Series C preferred stock		23,969
Proceeds from Initial Public Offering	36,000
Borrowings from Mid Cap credit facility	39,131	14,065
Repayments from Mid Cap credit facility	(35,229)	(12,816)
Repayments from Mid Cap term loan		(672)
Insurance financing proceeds	3,026
Insurance obligation payments	(756)
Capital lease obligation payments	(28)	(25)
Cash provided by financing activities	35,564	21,354
EFFECT OF EXCHANGE RATE ON CASH	1	2
NET CHANGE IN CASH AND RESTRICTED CASH FOR PERIOD	19,255	3,598
CASH AND RESTRICTED CASH AT BEGINNING OF PERIOD	20,708	5,797	$ 5,797
CASH AND RESTRICTED CASH AT END OF PERIOD	39,963	9,395	20,708
RECONCILIATION OF CASH AND RESTRICTED CASH
CASH	39,527	8,966
RESTRICTED CASH—Prepaid and other assets	307	250
RESTRICTED CASH—Other non-current assets	129	179
CASH AND RESTRICTED CASH AT END OF PERIOD	39,963	9,395	20,708
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for interest	1,743	791
Cash paid for taxes	15	3
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Deferred equity fundraising cost not paid	328
Capital lease		25
Initial Public Offering
FINANCING ACTIVITIES:
Issuance costs of stock	(5,098)
Series C Preferred Stock
FINANCING ACTIVITIES:
Issuance costs of stock		(2,980)
Horizon Term Loan
FINANCING ACTIVITIES:
Repayments from Mid Cap term loan			$ (4,900)
Debt issuance costs	(901)
Mid Cap Credit Facility
FINANCING ACTIVITIES:
Debt issuance costs	$ (581)	$ (205)