Balance Sheets $ in Thousands	Jun. 30, 2018 USD ($)
Current assets
Cash and cash equivalents	$ 35,292
Marketable securities	220,116
Accounts receivable	1,283
Income tax receivable	762
Prepaid expenses and other current assets	12,074
Total current assets	269,527
Property and equipment, net	9,401
Patents, licenses, and other intangible assets, net	11,531
Marketable securities - long term	299,971
Income tax receivable	762
Other assets	265
Total assets	591,457
Current liabilities
Accounts payable	4,916
Accrued expenses	5,923
Current portion of deferred rent	199
Deferred revenue	60,118
Total current liabilities	71,156
Deferred rent, less current portion	1,122
Total liabilities	72,278
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.01 par value: 10,000,000 authorized shares; -0- issued and outstanding shares at June 30, 2018 and December 31, 201
Common stock, $0.01 par value: 200,000,000 authorized shares at June 30, 2018 and December 31, 2017; 55,821,310 issued and outstanding at June 30, 2018 and 47,002,488 issued and outstanding at December 31, 2017	558
Additional paid-in capital	828,858
Accumulated other comprehensive loss	(2,008)
Accumulated deficit	(308,229)
Total stockholders' equity	519,179
Total liabilities and stockholders' equity	$ 591,457