BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 155,747	$ 126,898
Marketable securities	42,495
Receivable from stockholders		12,000
Accounts receivable	5,128
Prepaid and other current assets	4,577	456
Total current assets	207,947	139,354
Marketable securities, non-current	24,915
Property and equipment, net	905	473
Other assets	73
Total assets	233,840	139,827
Current liabilities:
Accounts payable	5,660	1,142
Accrued expenses	7,487	2,769
Related party liability	13,100	12,054
Total current liabilities	26,247	15,965
Commitments and contingencies (Note 11)
Redeemable convertible preferred stock	467,253	312,253
Stockholders’ deficit:
Common stock, $.001 par value; 46,159,941 and 41,254,509 shares authorized as of September 30, 2019 and December 31, 2018; 872,324 and 10 shares issued and outstanding as of September 30, 2019 and December 31, 2018	1
Additional paid-in capital	5,498	1,879
Accumulated other comprehensive loss	(30)
Accumulated deficit	(265,129)	(190,270)
Total stockholders’ deficit	(259,660)	(188,391)
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	233,840	139,827
Series A-1 Preferred Stock
Current liabilities:
Redeemable convertible preferred stock	142,253	142,253
Series A-2 Preferred Stock
Current assets:
Receivable from stockholders		12,000
Current liabilities:
Redeemable convertible preferred stock	170,000	$ 170,000
Series A-3 Preferred Stock
Current liabilities:
Redeemable convertible preferred stock	80,000
Series B Preferred Stock
Current liabilities:
Redeemable convertible preferred stock	$ 75,000