Other Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Prepaid Expense and Other Assets, Current [Abstract]
R&D expenses	$ 1,776	$ 979
Insurance expense	8	591
Software and subscriptions expense	347	337
Variable lease expense	118	118
Federal R&D tax credit receivable	0	108
Other	204	211
Total prepaid expenses and other current assets	$ 2,453	$ 2,344