Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	[1]
Current assets:
Cash and cash equivalents	$ 74,889	$ 98,426
Short-term investments	182,948	77,277
Receivable from collaboration partner	5,000
Prepaid expenses and other current assets	2,329	1,141
Amounts owed by a related party	114	25
Total current assets	265,280	176,869
Long-term investments	7,746
Property and equipment, net	11,762	11,230
Equity investment in related party	1,525	682
Restricted cash	203	203
Other long-term assets	205	1,502
Total assets	286,721	190,486
Current liabilities
Accounts payable	2,109	3,820
Accrued liabilities	6,667	3,137
Deferred revenue, current	6,250	5,000
Other current liabilities	1,585	769
Total current liabilities	16,611	12,726
Deferred revenue, noncurrent	18,546	18,587
Deferred rent	4,396	4,740
Other long-term liabilities	2,047	565
Total liabilities	41,600	36,618
Convertible preferred stock, $0.0001 par value, no shares and 120,958,867 shares authorized as of September 30, 2018 and December 31, 2017, respectively; no shares and 30,459,574 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively; aggregate liquidation preference of 226,725, as of December 31, 2017	0	226,196
Stockholders’ equity (deficit):
Preferred stock, $0.0001 par value, 10,000,000 shares and no shares authorized as of September 30, 2018 and December 31, 2017, respectively; no shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	0
Common stock, $0.0001 par value, 400,000,000 and 153,993,227 shares authorized as of September 30, 2018 and December 31, 2017, respectively; 44,453,724 and 4,090,898 shares issued and outstanding as of September 30, 2018 and December 31, 2017 respectively	4
Additional paid-in capital	355,758	948
Accumulated deficit	(110,533)	(73,234)
Accumulated other comprehensive loss	(108)	(42)
Total stockholders’ equity (deficit)	245,121	(72,328)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 286,721	$ 190,486

[1] The Condensed Consolidated Balance Sheet as of December 31, 2017 has been derived from the audited financial statements as of that date.