Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 49,010	$ 41,135
Marketable securities	175,067	265,744
Accounts receivable, net	7,441	4,933
Inventory, net	8,404	6,677
Prepaid expenses and other current assets	7,295	7,375
Total current assets	247,217	325,864
Property and Equipment, at cost:
Computer equipment and computer software	17,514	14,025
Laboratory equipment	13,758	12,786
Leasehold improvements	10,923	7,118
Buildings	4,792	4,777
Assets under construction	6,360	8,038
Furniture and fixtures	2,037	1,265
Property and Equipment, gross	55,384	48,009
Less-Accumulated depreciation	(19,151)	(13,913)
Net property and equipment	36,233	34,096
Other long-term assets	5,079	4,070
Total assets	288,529	364,030
Current Liabilities:
Accounts payable	3,135	3,308
Accrued liabilities	23,808	22,253
Debt and capital lease obligation, current portion	171	166
Other short-term liabilities	1,281	996
Total current liabilities	28,395	26,723
Long-term debt	4,711	4,789
Other long-term liabilities	5,054	4,601
Lease incentive obligation, less current portion	981	1,061
Total liabilities	39,141	37,174
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value Authorized—5,000,000 shares issued and outstanding—no shares at June 30, 2016 and December 31, 2015
Common stock, $0.01 par value Authorized—200,000,000 shares issued and outstanding—98,269,014 and 96,674,786 shares at June 30, 2016 and December 31, 2015	983	968
Additional paid-in capital	919,270	904,931
Accumulated other comprehensive loss	(17)	(433)
Accumulated deficit	(670,848)	(578,610)
Total stockholders' equity	249,388	326,856
Total liabilities and stockholders’ equity	$ 288,529	$ 364,030