Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 30,173	$ 71,157
Restricted cash	316	527
Short-term investments	19,885
Accounts receivable, net	4,093	4,017
Inventory	3,692	3,597
Prepaid expenses and other current assets	3,584	2,556
Total current assets	61,743	81,854
Property and equipment, net	27,126	25,602
Right-of-use and other assets	6,271	249
Total assets	95,140	107,705
Current liabilities:
Accounts payable	11,664	5,379
Accrued expenses and other current liabilities	14,298	15,022
Facility financing obligation		11,298
Senior convertible notes - current	2,520
Deferred revenue - current	32,212	36,885
Recognized loss on purchase commitments - current	3,593	6,657
Total current liabilities	64,287	75,241
Senior convertible notes	7,437	19,099
Credit facility	38,798
Promissory notes	70,019	72,089
Accrued interest - promissory notes	807	6,835
Recognized loss on purchase commitments - long term	85,858	91,642
Deferred revenue - long term	2,631	10,680
Milestone rights liability	7,263	7,201
Operating lease liabilities	2,746
Total liabilities	279,846	282,787
Commitments and contingencies
Stockholders' deficit:
Common stock, $0.01 par value - 280,000,000 shares authorized, 206,407,551 and 187,029,967 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	2,064	1,870
Additional paid-in capital	2,790,890	2,763,067
Accumulated other comprehensive loss	(20)	(19)
Accumulated deficit	(2,977,640)	(2,940,000)
Total stockholders' deficit	(184,706)	(175,082)
Total liabilities and stockholders' deficit	$ 95,140	$ 107,705