Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 140,513	$ 133,359
Marketable securities	22,270	58,685
Prepaid expenses and other current assets	1,938	2,193
Total current assets	164,721	194,237
Property and equipment, net	7,201	7,742
Right-of-use assets	62,232	63,492
Restricted cash	5,031	5,031
Long-term deposit and other assets	1,647	1,647
Total assets	240,832	272,149
Current liabilities:
Accounts payable	2,123	2,374
Accrued expenses and other current liabilities	8,786	10,716
Operating lease liability, current portion	3,338	3,246
Deferred revenue, current portion	10,435	10,137
Current portion of long-term debt	6,797	3,347
Total current liabilities	31,479	29,820
Deferred revenue, net of current portion	4,758	5,622
Operating lease liability, net of current portion	58,179	59,140
Long-term debt and accrued interest	23,449	26,700
Total liabilities	117,865	121,282
Commitments and contingencies (Note 7)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Additional paid-in capital	400,701	398,459
Accumulated deficit	(277,739)	(247,597)
Total stockholders' equity	122,967	150,867
Total liabilities and stockholders' equity	240,832	272,149
Voting Common Stock
Stockholders' equity:
Common stock	4	4
Non-voting Common Stock
Stockholders' equity:
Common stock	$ 1	$ 1