Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 46,755	$ 82,912
Marketable securities	58,406	75,923
Prepaid expenses and other current assets	2,765	5,766
Total current assets	107,926	164,601
Property and equipment, net	7,286	8,226
Operating lease right-of-use asset	14,858
Restricted cash	1,595	1,198
Other assets	28	40
Total assets	131,693	174,065
Current liabilities:
Accounts payable	3,384	3,412
Accrued expenses and other current liabilities	8,012	8,803
Deferred revenue - related party	4,916	14,610
Deferred rent		352
Operating lease liability	2,962
Total current liabilities	19,274	27,177
Deferred revenue - related party, non-current	33,676	39,342
Deferred rent, non-current		4,684
Operating lease liability, non-current	16,968
Convertible note payable, non-current	5,109
Total liabilities	75,027	71,203
Commitments and contingencies (Note 17)
Stockholders’ equity:
Preferred stock, $0.0001 par value per share; 5,000,000 shares authorized at December 31, 2019 and December 31, 2018; no shares issued and outstanding at December 31, 2019 and December 31, 2018
Common stock, $0.0001 par value; 150,000,000 authorized at December 31, 2019 and December 31, 2018; 27,893,337 and 27,772,600 shares issued and outstanding at December 31, 2019 and December 31, 2018, respectively	3	3
Additional paid-in capital	178,155	169,784
Accumulated other comprehensive income (loss)	103	(119)
Accumulated deficit	(121,595)	(66,806)
Total stockholders’ equity	56,666	102,862
Total liabilities and stockholders’ equity	$ 131,693	$ 174,065