CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 55,996	$ 10,435
Short-term investments	76,024	81,345
Accounts receivable, net of allowance for doubtful accounts of $263 and $238, respectively	11,417	11,720
Inventory	5,071	5,452
Prepaid expenses and other current assets	1,014	2,510
Total current assets	149,522	111,462
Long-term investments	0	1,278
Property and equipment, net	4,479	3,954
Other non-current assets	314	315
TOTAL ASSETS	154,315	117,009
Current liabilities:
Accounts payable	3,102	2,811
Accrued liabilities and other	8,719	11,605
Current portion of long-term borrowings	0	4,358
Total current liabilities	11,821	18,774
Long-term borrowings	39,368	34,865
Other long-term liabilities	1,095	362
TOTAL LIABILITIES	52,284	54,001
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; 28,838,577 and 25,163,803 shares issued and outstanding, respectively	3	3
Additional paid-in capital	331,896	258,121
Accumulated other comprehensive income	430	464
Accumulated deficit	(230,298)	(195,580)
TOTAL STOCKHOLDERS’ EQUITY	102,031	63,008
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 154,315	$ 117,009