Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 62,014	$ 118,564
Restricted cash	558	55
Marketable securities	172,120	134,714
Accounts receivable, net	12,908	4,441
Inventory	5,546	4,366
Prepaid expenses	10,097	5,175
Other current assets	1,193	2,191
Total current assets	264,436	269,506
Investments	42,235	176,978
Property and equipment, net	4,561	6,195
Intangible assets	7,581	8,180
Other assets	589	799
Total assets	319,402	461,658
Current liabilities:
Accounts payable	6,294	3,915
Accrued expenses and other current liabilities	41,759	49,512
Total current liabilities	48,053	53,427
Other non-current liabilities	118	189
Notes payable	176,180	166,006
Total liabilities	224,351	219,622
Commitments and contingencies
Stockholders’ equity:
Common stock, $.0001 par value; 200,000,000 shares authorized, 45,539,516 shares and 44,616,586 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	5	4
Additional paid-in-capital	1,158,417	1,124,630
Accumulated other comprehensive loss	(848)	(314)
Accumulated deficit	(1,062,523)	(882,284)
Total stockholders’ equity	95,051	242,036
Total liabilities and stockholders’ equity	$ 319,402	$ 461,658