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v3.26.1

Segment Reporting - Schedule of reportable segment net income (loss) (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2026 | Mar. 31, 2026 | Jun. 30, 2025 | Mar. 31, 2025 | Jun. 30, 2026 | Jun. 30, 2025
Segment Reporting [Line Items] |  |  |  |  |  |  |
Grant revenue |  | $ 736 |  | $ 0 |  | $ 1,094 | $ 0
Operating Expenses |  | 22,009 |  | 24,881 |  | 43,274 | 52,117
Impairment of long-lived assets |  | 5,807 |  | 0 |  | 5,807 | 0
Gain on sale of VOWST Business |  | 25,000 |  | 185 |  | 25,000 | 52,366
Net income (loss) |  | 4,581 | $ (19,913) | (19,855) | $ 32,682 | (15,332) | 12,827
Operating Segments [Member] |  |  |  |  |  |  |
Segment Reporting [Line Items] |  |  |  |  |  |  |
Grant revenue |  | 736 |  | 0 |  | 1,094 | 0
R&D personnel-related (including stock-based compensation) |  | 3,680 |  | 6,084 |  | 9,600 | 12,202
G&A personnel-related (including stock-based compensation) |  | 2,671 |  | 3,725 |  | 5,962 | 7,898
Professional fees |  | 1,442 |  | 2,155 |  | 3,156 | 5,335
Facility-related and other |  | 2,948 |  | 4,373 |  | 6,013 | 8,908
Impairment of long-lived assets |  | 5,807 |  | 0 |  | 5,807 | 0
Gain on sale of VOWST Business | [1] | (25,000) |  | (185) |  | (25,000) | (52,366)
Other segment (income) expense | [2] | (367) |  | (3,149) |  | (1,266) | (7,356)
Live Biotherapeutics Platform [Member] | Operating Segments [Member] |  |  |  |  |  |  |
Segment Reporting [Line Items] |  |  |  |  |  |  |
Operating Expenses |  | 4,875 |  | 5,808 |  | 11,408 | 10,931
SER-155 [Member] | Operating Segments [Member] |  |  |  |  |  |  |
Segment Reporting [Line Items] |  |  |  |  |  |  |
Operating Expenses |  | $ 99 |  | $ 1,044 |  | $ 746 | $ 1,621
[1] | See Note 3, Discontinued Operations and TSA, for further details.
[2] | [1] Other segment (income) expense includes manufacturing services expenses, research and development expenses on early stage programs, interest income and other (income) expense, net.

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