Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	[1]
Current assets:
Cash and cash equivalents	$ 76,068	$ 71,064
Short-term investments	148,330	185,480
Prepaid expenses and other current assets	3,273	2,321
Amounts owed by a related party	62	83
Total current assets	227,733	258,948
Long-term investments	0	3,181
Property and equipment, net	10,362	11,107
Equity investment in related party	357	1,202
Restricted cash	203	203
Other long-term assets	319	284
Total assets	238,974	274,925
Current liabilities
Accounts payable	2,448	3,102
Accrued liabilities	15,552	6,023
Deferred revenue, current	7,000	6,250
Other current liabilities	1,513	1,560
Total current liabilities	26,513	16,935
Deferred revenue, noncurrent	10,522	16,984
Deferred rent	4,010	4,272
Other long-term liabilities	1,283	1,792
Total liabilities	42,328	39,983
Stockholders’ equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of June 30, 2019 and December 31, 2018; no shares issued and outstanding as of June 30, 2019 and December 31, 2018	0
Common stock, $0.0001 par value, 400,000,000 shares authorized as of June 30, 2019 and December 31, 2018, respectively; 45,854,213 and 44,537,946 shares issued and outstanding as of June 30, 2019 and December 31, 2018 respectively	4	4
Additional paid-in capital	362,905	357,873
Accumulated deficit	(166,376)	(122,828)
Accumulated other comprehensive income (loss)	113	(107)
Total stockholders’ equity	196,646	234,942
Total liabilities, convertible preferred stock and stockholders’ equity	$ 238,974	$ 274,925

[1] The Condensed Consolidated Balance Sheet as of December 31, 2018 has been derived from the audited financial statements as of that date.