Operating Expenses by Nature - Schedule of Operating Expenses by Nature (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Expense By Nature [Abstract] | |||
| External research and development costs | $ 38,287 | $ 51,803 | $ 70,531 |
| Staff costs (note 16) | 18,788 | 19,643 | 24,556 |
| Professional fees | 12,175 | 3,994 | 7,072 |
| Rents | 60 | 22 | 21 |
| Travel expenses | 229 | 156 | 1,398 |
| Patent registration costs | 887 | 813 | 882 |
| Depreciation | 736 | 721 | 737 |
| Other | 3,466 | 2,566 | 1,914 |
| Total operating expenses by nature | $ 74,627 | $ 79,718 | $ 107,111 |