Balance Sheet Components - Accrued and Other Liabilities (Details) - USD ($) $ in Thousands |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Accrued and Other Liabilities | ||
| Accrued clinical trial expense | $ 4,010 | $ 4,681 |
| Accrued manufacturing expense | 839 | 321 |
| Personnel related | 1,846 | 2,225 |
| Accrued legal and accounting | 265 | 197 |
| Other | 121 | 180 |
| Total of accrued and other liabilities | $ 7,081 | $ 7,604 |