CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 82,033,209	$ 28,575,085
Marketable securities, at fair value	37,914,482	24,388,403
Accounts receivable from collaboration	2,273,421	0
Prepaid expenses and other current assets	897,400	611,176
Total current assets	123,118,512	53,574,664
Long-term assets
Marketable securities, at fair value	3,347,213	2,435,753
Property, plant and equipment, net	860,026	214,687
Security deposits	339,558	255,366
Intangible assets	29,000,000	29,000,000
Goodwill	12,638,136	12,638,136
Total long-term assets	46,184,933	44,543,942
Total assets	169,303,445	98,118,606
Current liabilities
Accounts payable	2,123,939	2,368,131
Accrued expenses	6,139,000	4,752,823
Deferred revenue - short-term	5,229,227	0
Total current liabilities	13,492,166	7,120,954
Long-term liabilities
Deferred tax liabilities	2,135,802	11,119,651
Deferred revenue - long-term	40,555,708	0
Total long-term liabilities	42,691,510	11,119,651
Total liabilities	56,183,676	18,240,605
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.001 par value; 5,000,000 shares authorized; 0 shares issued and outstanding	0	0
Common stock, $0.001 par value; 50,000,000 shares authorized; 20,137,974 and 17,246,754 shares issued and outstanding as of December 31, 2017 and December 31, 2016, respectively	20,138	17,247
Additional paid-in capital	364,528,037	288,688,990
Accumulated other comprehensive loss	(392,391)	(600,769)
Accumulated deficit	(251,036,015)	(208,227,467)
Total stockholders' equity	113,119,769	79,878,001
Total liabilities and stockholders' equity	$ 169,303,445	$ 98,118,606