Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 106,760	$ 29,147
Accounts receivable, net	5,283	4,267
Inventory	2,614	2,468
Prepaid expenses and other current assets	2,082	1,123
Total current assets	116,739	37,005
Property and equipment, net	1,343	1,359
Other assets	897	574
Total Assets	118,979	38,938
Current liabilities:
Accounts payable	2,102	2,513
Accrued expenses	6,383	7,511
Deferred revenue	1,813	1,970
Current portion of long-term debt	5,000	0
Total current liabilities	15,298	11,994
Long-term debt, net	25,198	29,556
Deferred revenue	2,032	2,275
Deferred rent	103	151
Convertible preferred stock warrant liability		478
Total Liabilities	42,631	44,454
Commitments and contingencies (Note 14)
Convertible preferred stock, $0.01 par value: 308,593 shares previously authorized prior to initial public offering, issuable in series; no and 304,958 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively; no liquidation value at September 30, 2018		187,136
Stockholders’ Equity (Deficit):
Preferred stock, $0.01 par value: 10,000 shares authorized; no shares issued or outstanding at September 30, 2018 and December 31, 2017
Common stock, $0.01 par value: 200,000 shares authorized; 17,579 and 231 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	176	2
Additional paid-in capital	291,072	4,292
Accumulated deficit	(214,900)	(196,946)
Total Stockholders' Equity (Deficit)	76,348	(192,652)
Total Liabilities, Convertible Preferred Stock and Stockholders’ Equity (Deficit)	$ 118,979	$ 38,938