Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 36,739	$ 47,758
Accounts receivable, net	5,720	6,294
Inventories, net	7,779	6,824
Prepaid expense and other current assets	787	1,200
Total current assets	51,025	62,076
Property and equipment, net	6,744	6,097
Right-of-use assets	1,502
Other assets	321	447
Total assets	59,592	68,620
Current liabilities:
Accounts payable	5,502	4,916
Accrued expense and other current liabilities	9,480	8,851
Current portion of operating lease obligations	281
Current portion of financing lease obligations	128
Current portion of financing lease obligations		123
Total current liabilities	15,391	13,890
Long-term debt, net (related parties)	41,298	40,192
Operating long-term lease obligations	1,330
Deferred rent		109
Financing lease liabilities	106	140
Total liabilities	58,125	54,331
Commitments and contingencies
Stockholders' equity
Convertible preferred stock, $0.001 par value, 50,000,000 shares authorized at March 31, 2019; 2,750,000 shares issued and outstanding at March 31, 2019 and December 31, 2018. (aggregate liquidation value of $31,961 and $31,411 at March 31, 2019 and December 31, 2018, respectively)	3	3
Common stock, $0.001 par value, 300,000,000 shares authorized; 102,180,564 shares issued and 102,172,710 outstanding at March 31, 2019 and 99,956,291 shares issued and 99,948,437 shares outstanding at December 31, 2018.	102	100
Additional paid-in capital	535,941	534,081
Accumulated deficit	(534,555)	(519,871)
Treasury stock, at cost (7,854 shares)	(24)	(24)
Total stockholders' equity	1,467	14,289
Total liabilities and stockholders' equity	$ 59,592	$ 68,620