CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 77,383	$ 63,798
Prepaid expenses and other current assets	3,123	1,264
Total current assets	80,506	65,062
Property and equipment, net	3,707	4,159
Other assets	389	389
Total assets	84,602	69,610
Current liabilities:
Accounts payable	1,143	1,771
Accrued expenses	3,642	2,488
Deferred revenue, current	4,000
Other current liabilities	471	384
Total current liabilities	9,256	4,643
Deferred rent, net of current portion	2,225	969
Commitments
Convertible preferred stock, $0.0001 par value: no shares and 104,018,468 shares authorized at December 31, 2019 and 2018, respectively; no shares and 16,415,281 shares issued and outstanding at December 31, 2019 and 2018, respectively		161,111
Stockholders' equity (deficit):
Preferred stock, $0.0001 par value: 50,000,000 shares authorized; no shares issued and outstanding at December 31, 2019 and 2018
Common stock, $0.0001 par value; 500,000,000 shares authorized; 21,833,037 and 878,413 shares issued and outstanding at December 31, 2019 and 2018, respectively	2	1
Additional paid-in capital	235,049	22,441
Related party promissory note for the purchase of common stock		(598)
Accumulated other comprehensive income (loss)	20	(4)
Accumulated deficit	(161,950)	(118,953)
Total stockholders' equity (deficit)	73,121	(97,113)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 84,602	$ 69,610