Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 116,687	$ 19,392
Short-term investments	191,698	165,260
Accounts receivable, net	13,178	12,221
Inventory	4,771	4,504
Other current assets	6,324	7,053
Total current assets	332,658	208,430
Fixed assets, net	5,213	4,631
Restricted cash	1,100	1,100
Other assets	9,948	2,972
Total assets	348,919	217,133
Current liabilities:
Accounts payable and accrued expenses	24,799	17,373
Current portion of deferred revenue	3,743	3,373
Other current liabilities	0	1,159
Total current liabilities	28,542	21,905
Deferred revenue	3,115	4,201
Notes payable	0	82,165
Deferred rent and other long-term liabilities	2,793	3,059
Total liabilities	34,450	111,330
Commitments and contingencies	0	0
Stockholders' equity:
Preferred stock, $0.01 par value; 1,000,000 shares authorized; 0 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	0	0
Common stock, $0.01 par value; 200,000,000 shares authorized; 147,122,377 and 136,662,175 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	1,471	1,367
Additional paid-in capital	886,140	650,249
Accumulated deficit	(573,224)	(545,841)
Accumulated other comprehensive income	82	28
Total stockholders' equity	314,469	105,803
Total liabilities and stockholders' equity	$ 348,919	$ 217,133