BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 109,004	$ 140,717
Receivables, net of allowance	15	446
Prepaid expenses and other current assets	17,690	11,358
Total current assets	126,709	152,521
Property and equipment, net	682	581
Deposits	128	128
Other non-current assets	493	494
Total assets	128,012	153,724
Current liabilities:
Accounts payable	2,031	2,008
Accrued expenses	7,392	8,906
Deferred rent - current portion	223	348
Deferred revenue - current portion	6,389	6,861
Total current liabilities	16,035	18,123
Deferred rent, net of current portion	200	313
Deferred revenue, net of current portion	44,722	47,917
Series 1 preferred stock issuance obligation	119,045
Total liabilities	180,002	66,353
Commitments and contingencies (Note 5)
Stockholders' equity (deficit):
Preferred stock, $0.001 par value; 30,000,000 shares authorized, 250,000 designated as Series 1 preferred stock, no shares issued and outstanding
Common stock, $0.001 par value; 250,000,000 shares authorized; 131,732,423 and 131,718,579 shares issued and outstanding at June 30, 2016 and December 31, 2015, respectively	132	132
Additional paid-in capital - common stock	583,797	579,939
Accumulated deficit	(635,919)	(492,700)
Total stockholders' equity (deficit)	(51,990)	87,371
Total liabilities and stockholders' equity (deficit)	$ 128,012	$ 153,724