Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 85,333	$ 11,294
Prepaid expenses and other current assets	5,337	5,117
Receivable on issuance of convertible preferred stock	5,473	39,669
Total current assets	96,143	56,080
Restricted cash	241	231
Tax credit receivable - noncurrent	865
Operating lease right-of-use asset	905	298
Total assets	98,154	56,609
Current liabilities
Accounts payable	4,463	3,329
Accrued expenses and other current liabilities	3,818	4,598
Total current liabilities	8,281	7,927
Operating lease liabilities, net of current portion	589	211
Total liabilities	8,870	8,138
Commitments and contingencies (Note 8)
Convertible preferred stock
Total convertible preferred stock	181,021	119,619
Stockholders’ deficit
Additional paid-in capital	1,361	826
Accumulated deficit	(92,783)	(69,523)
Accumulated other comprehensive loss	(315)	(2,451)
Total stockholders’ deficit	(91,737)	(71,148)
Total liabilities, convertible preferred stock and stockholders’ deficit	98,154	56,609
Series B Convertible Preferred Stock
Convertible preferred stock
Total convertible preferred stock	13,414	13,414
Series C Convertible Preferred Stock
Convertible preferred stock
Total convertible preferred stock	106,205	$ 106,205
Series D Convertible Preferred Stock
Current assets
Receivable on issuance of convertible preferred stock	5,500
Convertible preferred stock
Total convertible preferred stock	$ 61,402