CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 59,863	$ 53,581
Short-term investments	100,988	142,851
Accounts receivable, net of allowance for doubtful accounts of $264 and $263, respectively	12,617	13,611
Inventory	10,246	5,633
Prepaid expenses and other current assets	1,934	2,565
Total current assets	185,648	218,241
Property and equipment, net	7,913	4,527
Other non-current assets	405	374
TOTAL ASSETS	193,966	223,142
Current liabilities:
Accounts payable	4,139	3,271
Accrued liabilities and other	10,425	10,199
Total current liabilities	14,564	13,470
Long-term borrowings	34,922	39,455
Other long-term liabilities	862	854
TOTAL LIABILITIES	50,348	53,779
Commitments and contingencies (Note 6)
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; 33,450,995 and 32,583,220 shares issued and outstanding, respectively	3	3
Additional paid-in capital	424,561	408,113
Accumulated other comprehensive income	426	524
Accumulated deficit	(281,372)	(239,277)
TOTAL STOCKHOLDERS’ EQUITY	143,618	169,363
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 193,966	$ 223,142