Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 342	$ 365
Prepaid insurance	568	809
Prepaid research and development expenses	687	133
Short-term Italian research and development refundable tax credit	971	993
Other current assets	48	81
Total prepaid expenses and other current assets	$ 2,616	$ 2,381