Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 23,168	$ 47,758
Accounts receivable, net	6,420	6,294
Inventories, net	8,662	6,824
Prepaid expense and other current assets	1,362	1,200
Total current assets	39,612	62,076
Property and equipment, net	6,667	6,097
Right-of-use assets	2,393	0
Other assets	560	447
Total assets	49,232	68,620
Current liabilities:
Accounts payable	5,274	4,916
Accrued expense and other current liabilities	13,198	8,851
Current portion of operating lease obligations	408	0
Current portion of financing lease obligations	137
Current portion of financing lease obligations		123
Total current liabilities	19,017	13,890
Long-term debt, related parties (net)	17,017	40,192
Operating lease obligations	2,138	0
Deferred rent		109
Financing lease liabilities	36	140
Total liabilities	38,208	54,331
Commitments and contingencies
Stockholders' equity
Common stock, $0.001 par value, 300,000,000 shares authorized; 8,271,895 shares issued and 8,271,503 shares outstanding at September 30, 2019 and 4,997,544 shares issued and 4,997,152 shares outstanding at December 31, 2018.	8	5
Additional paid-in capital	572,851	534,176
Accumulated deficit	(561,831)	(519,871)
Treasury stock, at cost (392 shares)	(24)	(24)
Total stockholders' equity	11,024	14,289
Total liabilities and stockholders' equity	49,232	68,620
Series A Preferred Stock
Stockholders' equity
Preferred stock	3	3
Total stockholders' equity	3	3
Series B Preferred Stock
Stockholders' equity
Preferred stock	17	0
Total stockholders' equity	$ 17	$ 0