Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 242,650	$ 197,945
Short-term investments	65,269	35,717
Prepaid expenses and other current assets	2,057	4,028
Total current assets	309,976	237,690
Property, plant and equipment, net	14,391	7,857
Other assets	2,617	2,707
Total assets	326,984	248,254
Current liabilities
Accounts payable and other current liabilities	13,265	18,820
Interest payable	545	551
Total current liabilities	13,810	19,371
Convertible notes, net	123,692	123,539
Other non-current liabilities	4,440	0
Total liabilities	141,942	142,910
Commitments and contingencies (Note 11)
Stockholders’ equity
Preferred stock, $0.001 par value; 15,000,000 shares authorized as of June 30, 2017 and December 31, 2016; None issued and outstanding	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized as of June 30, 2017 and December 31, 2016; 36,337,542 and 33,458,607 shares issued and outstanding as of June 30, 2017 and December 31, 2016, respectively	36	33
Additional paid-in capital	555,930	422,002
Accumulated other comprehensive loss	(81)	(68)
Accumulated deficit	(370,843)	(316,623)
Total stockholders’ equity	185,042	105,344
Total liabilities and stockholders’ equity	$ 326,984	$ 248,254