Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 50,756	$ 100,297
Short-term marketable securities	82,622
Accounts receivable	731	1,051
Prepaid expenses and other current assets	2,616	825
Total current assets	136,725	102,173
Property and equipment, net	2,325	2,483
Long-term marketable securities	3,482
Other assets	384	431
Total assets	142,916	105,087
Current liabilities:
Accounts payable	3,215	2,068
Accrued expenses	4,607	3,428
Deferred rent	215	159
Deferred revenue	16,476	22,731
Total current liabilities	24,513	28,386
Deferred rent, net of current portion	128	299
Deferred revenue, net of current portion	34,633	37,571
Commitments (Note 10)
Stockholders’ equity (deficit)
Preferred stock, $0.0001 par value; 25,000,000 and 0 shares authorized; 0 shares issued and outstanding at September 30, 2017 and December 31, 2016, respectively
Common stock, $0.0001 par value; 175,000,000 and 95,000,000 shares authorized; 22,734,333 and 1,294,352 shares issued and outstanding at September 30, 2017 and December 31, 2016, respectively	3	1
Additional paid-in capital	167,565	3,551
Accumulated other comprehensive loss	(15)
Accumulated deficit	(83,911)	(59,171)
Total stockholders’ equity (deficit)	83,642	(55,619)
Total liabilities, convertible preferred stock, and stockholders’ equity (deficit)	$ 142,916	105,087
Series A-1 convertible preferred stock
Current liabilities:
Convertible redeemable preferred shares, carrying Amount		26,336
Series B-1 convertible preferred stock
Current liabilities:
Convertible redeemable preferred shares, carrying Amount		35,232
Series C-1 convertible preferred stock
Current liabilities:
Convertible redeemable preferred shares, carrying Amount		$ 32,882