CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 12,614	$ 25,120
Short-term investments	83,609	97,103
Accounts receivable, net of allowance for doubtful accounts of $310 and $263, respectively	9,918	8,486
Inventory	4,953	3,343
Prepaid expenses and other current assets	1,619	1,990
Total current assets	112,713	136,042
Long-term investments	5,273	0
Property and equipment, net	3,025	2,154
Other non-current assets	305	325
TOTAL ASSETS	121,316	138,521
Current liabilities:
Accounts payable	2,623	2,146
Accrued liabilities and other	10,211	6,860
Total current liabilities	12,834	9,006
Long-term borrowings	39,158	38,963
Other long-term liabilities	363	360
TOTAL LIABILITIES	52,355	48,329
Commitments and contingencies
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value; 100,000,000 shares authorized; 24,965,512 and 24,450,757 shares issued and outstanding, respectively	3	3
Additional paid-in capital	254,965	246,927
Accumulated other comprehensive income	475	439
Accumulated deficit	(186,482)	(157,177)
TOTAL STOCKHOLDERS’ EQUITY	68,961	90,192
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 121,316	$ 138,521