CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 192,689	$ 135,173
Restricted cash	873	460
Prepaid expenses and other current assets	2,959	152
Total current assets	196,521	135,785
Property and equipment, net	12,329	11,407
Other assets	4,200	436
Total assets	213,050	147,628
Current liabilities:
Accounts payable	1,990	2,483
Accrued liabilities	2,171	2,411
Deferred rent, current portion	6	28
Term loan, current portion	833	387
Deferred revenue, current portion	6,524	4,989
Total current liabilities	11,524	10,298
Deferred rent, net of current portion	322	242
Term loan, net of current portion	4,167	73
Deferred revenue, net of current portion	18,442	21,736
Total liabilities	34,455	32,349
Commitments and contingencies (Note 6)
Redeemable preferred stock:
Total redeemable preferred stock		162,223
Stockholders’ equity (deficit):
Preferred stock; par value of $0.001 per share, 10,000,000 and 0 shares authorized at June 30, 2019 and December 31, 2018. No shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively
Common stock, par value of $0.001 per share; 100,000,000 and 158,745,671 shares authorized at June 30, 2019 and December 31, 2018, respectively, 22,714,765 and 1,374,812 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	23	11
Additional paid-in capital	240,245	342
Accumulated deficit	(61,673)	(47,297)
Total stockholders’ equity (deficit)	178,595	(46,944)
Total liabilities, preferred stock and stockholders’ equity (deficit)	$ 213,050	147,628
Series A Preferred Stock
Redeemable preferred stock:
Total redeemable preferred stock		71,000
Series B Preferred Stock
Redeemable preferred stock:
Total redeemable preferred stock		$ 91,223