Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (18,586)	$ (11,150)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,130	488
Stock-based compensation	847	236
Changes in current assets and liabilities:
Prepaid expenses and other assets	(2,219)	(22)
Right-of-use assets and lease liabilities, net	40	258
Accounts payable	1,593	505
Accrued expense and other liabilities	(325)	(198)
Deferred revenue	(3,137)	19,999
Net cash used in operating activities	(20,657)	10,116
Cash flows from investing activities:
Purchases of property and equipment	(6,877)	(1,510)
Net cash used in investing activities	(6,877)	(1,510)
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	99,730
Proceeds from exercise of stock options	170	247
Payment of deferred offering costs	(960)
Net cash provided by financing activities	98,940	247
Net increase (decrease) in cash, cash equivalents and restricted cash	71,406	8,853
Cash, cash equivalents, and restricted cash - beginning of period	35,386	42,359
Cash, cash equivalents, and restricted cash - end of period	106,792	51,212
Supplemental cash flow information:
Purchase of property and equipment in accounts payable and accrued liabilities	379	$ 228
Deferred offering costs included in accrued expenses	$ 1,580