Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash, cash equivalents and restricted cash	$ 34,755	$ 46,013
Short-term investments	4,958	49,704
Accounts receivable	3,008	20
Prepaid expenses and other current assets	2,815	3,714
Total current assets	45,536	99,451
Property and equipment, net	11,731	15,585
Right-of-use assets, net	24,840	25,715
Intangible assets, net	4,289	5,020
Goodwill	4,508	4,508
Other long-term assets	926	3,568
Total assets	91,830	153,847
Current liabilities:
Accounts payable	1,584	5,514
Deferred grant revenue	0	2,000
Other accrued current liabilities	5,634	8,084
Current portion of operating lease liability	2,703	2,228
Current portion of liability related to sale of future royalties	3,803	95
Total current liabilities	13,724	17,921
Operating lease liability, net of current portion	17,385	19,477
Liability related to sale of future royalties, net of current portion	2,623	5,621
Other long-term liabilities	293	231
Total liabilities	34,025	43,250
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred Stock: $0.0001 par value; 5,000,000 shares authorized; none issued and outstanding as of December 31, 2023 or 2022	0	0
Common Stock: $0.0001 par value; 250,000,000 shares authorized as of December 31, 2023 and 2022; 153,959,853 shares issued and 153,452,833 shares outstanding as of December 31, 2023 and 134,199,429 shares issued and outstanding as of December 31, 2022	15	13
Additional paid-in capital	467,731	437,992
Treasury Stock at cost, 507,020 shares and none as of December 31, 2023 and 2022, respectively	(366)	0
Accumulated deficit	(409,574)	(327,109)
Accumulated other comprehensive loss	(1)	(299)
Total stockholders’ equity	57,805	110,597
Total liabilities and stockholders’ equity	$ 91,830	$ 153,847