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Millendo Merger - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020 | Jun. 25, 2021 | Dec. 31, 2020
Business Acquisition [Line Items] |  |  |  |  |  |
Cash and Cash Equivalents, at Carrying Value | $ 68,413 |  | $ 68,413 |  |  | $ 18,820
Operating Lease, Right-of-Use Asset | 3,673 |  | 3,673 |  |  | $ 1,877
Operating Lease, Liability | 4,158 |  | 4,158 |  |  |
Share-based compensation expense | 411 | $ 227 | 531 | $ 230 |  |
General and Administrative Expense [Member] |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Share-based compensation expense | 366 | $ 51 | 409 | $ (1) |  |
Private Tempest [Member] |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Cash and Cash Equivalents, at Carrying Value |  |  |  |  | $ 17,000 |
Prepaid Expense and Other Assets |  |  |  |  | 1,400 |
Accrued Liabilities and Other Liabilities |  |  |  |  | 500 |
Operating Lease, Right-of-Use Asset |  |  |  |  | 2,100 |
Operating Lease, Liability |  |  |  |  | $ 2,100 |
Private Tempest [Member] | Additional Paid-in Capital [Member] |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Business Acquisition, Transaction Costs | 6,100 |  | 6,100 |  |  |
Private Tempest [Member] | General and Administrative Expense [Member] |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Share-based compensation expense | $ 200 |  | $ 200 |  |  |

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