CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 38,220	$ 51,575
Short-term investments	176,517	78,084
Prepaid expenses and other current assets	6,948	1,945
Total current assets	221,685	131,604
Property and equipment, net	35,637	3,154
Deferred offering costs		1,000
Restricted cash	1,772	1,772
Total assets	259,094	137,530
Current liabilities:
Accounts payable	15,732	2,538
Accrued expenses and other liabilities	5,040	2,860
Deferred rent	977	123
Deferred revenue	3,684	3,341
Total current liabilities	25,433	8,862
Non-current liabilities:
Deferred rent, net of current portion	9,470	291
Deferred revenue, net of current portion	29,474	30,069
Total liabilities	64,377	39,222
Commitments and contingencies (Note 8)
Convertible preferred stock:
Total convertible preferred stock		137,762
Stockholders’ equity (deficit):
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of December 31, 2018 and no shares authorized as of December 31, 2017; no shares issued and outstanding at December 31, 2018 and December 31, 2017
Common stock, $0.0001 par value; 200,000,000 and 170,000,000 shares authorized as of December 31, 2018 and 2017, respectively; 37,509,815 and 2,902,109 shares issued as of December 31, 2018 and 2017, respectively; and 37,358,526 and 2,637,011 shares outstanding as of December 31, 2018 and 2017, respectively	3
Additional paid-in capital	292,187	800
Accumulated other comprehensive loss	(77)	(73)
Accumulated deficit	(97,396)	(40,181)
Total stockholders’ equity (deficit)	194,717	(39,454)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 259,094	137,530
Series A Convertible Preferred Stock
Convertible preferred stock:
Total convertible preferred stock		42,994
Series B Convertible Preferred Stock
Convertible preferred stock:
Total convertible preferred stock		$ 94,768