CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 69,663	$ 45,555
Restricted cash		105
Short-term investments	268,200
Prepaid expenses and other current assets	3,665	1,444
Total current assets	341,528	47,104
Property and equipment, net	2,360	125
Restricted cash	210
Deferred offering costs		25
Deferred tax assets	1,173	238
Advanced clinical payments	1,830
Total assets	347,101	47,492
Current liabilities:
Accounts payable	4,668	1,218
Accrued expenses	13,353	6,212
Accrued milestone	10,000	10,000
Total current liabilities	28,021	17,430
Deferred rent	167
Total liabilities	28,188	17,430
Commitments and contingencies (Note 11)
Convertible preferred shares (Series A, B and C), $0.000273235 par value; 0 shares and 22,885,492 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively; aggregate liquidation preference of $0 and $120,000 as of September 30, 2018 and December 31, 2017, respectively		119,770
Shareholders’ equity (deficit):
Additional paid-in capital	470,600	1,289
Accumulated other comprehensive income	(55)
Accumulated deficit	(151,645)	(90,998)
Total shareholders’ equity (deficit)	318,913	(89,708)
Total liabilities, convertible preferred shares and shareholders’ equity (deficit)	347,101	47,492
Class A common shares
Shareholders’ equity (deficit):
Common stock value	4
Class B common shares
Shareholders’ equity (deficit):
Common stock value	1	$ 1
Class A1 common shares
Shareholders’ equity (deficit):
Common stock value	4
Class B1 common shares
Shareholders’ equity (deficit):
Common stock value	$ 4