Property and equipment, net - Schedule of Property Plant and Equipment (Details) - USD ($) |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Property Plant And Equipment [Line Items] | ||
| Laboratory equipment | $ 0 | $ 955,000 |
| Less accumulated depreciation | 0 | 661,000 |
| Property and equipment, net | 0 | 294,000 |
| Laboratory Equipment | ||
| Property Plant And Equipment [Line Items] | ||
| Laboratory equipment | 0 | 808,000 |
| Computer Equipment | ||
| Property Plant And Equipment [Line Items] | ||
| Laboratory equipment | 0 | 29,000 |
| Furniture and Fixtures | ||
| Property Plant And Equipment [Line Items] | ||
| Laboratory equipment | 0 | 53,000 |
| Leasehold Improvements [Member] | ||
| Property Plant And Equipment [Line Items] | ||
| Laboratory equipment | $ 0 | $ 65,000 |