Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 87,769	$ 87,229
Marketable securities	87,991	171,555
Accounts receivable, net	29,316	13,121
Inventories	14,773	7,637
Prepaid expenses and other current assets	5,235	5,500
Total current assets	225,084	285,042
Property and equipment, net	10,651	10,710
Right-of-use assets	8,618
Total assets	244,353	295,752
Current liabilities
Accounts payable	12,088	12,340
Accrued expenses and other current liabilities	24,419	14,310
Operating lease liabilities	1,283
Current portion of long-term debt		9,967
Total current liabilities	37,790	36,617
Long-term operating lease liability, net	7,865
Long-term debt, net	40,070	3,640
2024 convertible notes, net	151,204	144,879
Other long-term liabilities	251	537
Total liabilities	237,180	185,673
Commitments and contingencies
Preferred stock, $0.001 par value; 10,000,000 shares authorized at September 30, 2019 and December 31, 2018 and 0 shares issued and outstanding at September 30, 2019 and December 31, 2018	0	0
Stockholders' equity
Common stock, $0.001 par value; 100,000,000 shares authorized; 38,152,405 and 37,946,341 shares issued and outstanding, at September 30, 2019 and December 31, 2018, respectively	38	38
Additional paid-in capital	642,087	628,944
Accumulated other comprehensive income (loss)	131	(77)
Accumulated deficit	(635,083)	(518,826)
Total stockholders' equity	7,173	110,079
Total liabilities and stockholders' equity	$ 244,353	$ 295,752