Will the FDA approve imsidolimab for generalized pustular psoriasis?
deadline 2026-12-12
confidence medium
tier 2 evidence
44%Asturna estimate
Resolution criterion
Resolves YES if the FDA publishes an approval (Drugs@FDA or an official Vanda Pharmaceuticals press release) for imsidolimab in generalized pustular psoriasis (GPP) on or before 12 December 2026. A complete response letter, a postponement of the PDUFA date, or the absence of a decision count as no.
Verified starting state
BLA accepted, target action date 12 December 2026. GPP flares can be life-threatening (sepsis-like systemic inflammation, organ failure); an IL-36 receptor antagonist of the same mechanism class (spesolimab) is already approved for this indication. (Vanda Pharmaceuticals press release, 25 February 2026)
What pushes it up
- Imsidolimab shares the IL-36 receptor antagonist mechanism of action with spesolimab, an already FDA-approved therapy for generalized pustular psoriasis, strongly supporting biological plausibility [tier 1]
- As of 9 October 2026, just two months before the 12 December 2026 target action date, the BLA remains on schedule without public notice of major review deficiencies or an advisory committee rejection [tier 1]
What pushes it down
- The resolution criteria strictly require approval on or before 12 December 2026, meaning any standard three-month PDUFA extension for chemistry, manufacturing, or clinical data review resolves to NO [tier 1]
- Late-cycle review extensions or Complete Response Letters are common risks during first-cycle biologic reviews, especially under stringent manufacturing and inspection standards [tier 2]
What would move this number most
Whether the FDA requires additional data or facility inspections that would trigger a three-month PDUFA extension or a Complete Response Letter before 12 December 2026.
How this number is built
| Deadline | 2026-12-12 |
| Base rate | 40% |
| Best evidence | tier 2 · 2 article(s) used |
| Independent runs | 42 · 45 (spread 3 pts) |
| Confidence | medium |
| Evidence cap | not triggered |
| Last revised | 2026-10-09 09:08 |
| Model | gemini-flash-latest |
Sources consulted
Probability history
2026-10-09 09:08 44% 60 article(s) on file · gemini-flash-latest
- What pushes it up. Imsidolimab shares the IL-36 receptor antagonist mechanism of action with spesolimab, an already FDA-approved therapy for generalized pustular psoriasis, strongly supporting biological plausibility [tier 1]
- What pushes it up. As of 9 October 2026, just two months before the 12 December 2026 target action date, the BLA remains on schedule without public notice of major review deficiencies or an advisory committee rejection [tier 1]
- What pushes it down. The resolution criteria strictly require approval on or before 12 December 2026, meaning any standard three-month PDUFA extension for chemistry, manufacturing, or clinical data review resolves to NO [tier 1]
- What pushes it down. Late-cycle review extensions or Complete Response Letters are common risks during first-cycle biologic reviews, especially under stringent manufacturing and inspection standards [tier 2]
- What would move this number most. Whether the FDA requires additional data or facility inspections that would trigger a three-month PDUFA extension or a Complete Response Letter before 12 December 2026.
2026-10-06 09:18 40% 43 article(s) on file · qwen/qwen3.8-27b (Groq)
- What pushes it up. The BLA has been accepted with a target action date of 12 December 2026, indicating the FDA is on track to review the application within the deadline [tier 1].
- What pushes it up. The indication (GPP) is life-threatening, and a mechanism-similar drug (spesolimab) is already approved, suggesting a clear regulatory pathway and unmet need [tier 1].
- What pushes it down. No recent tier 1 or tier 2 articles confirm a specific approval decision or positive advisory committee vote for imsidolimab, leaving the outcome uncertain until the PDUFA date [tier 1-2].
- What pushes it down. The base rate for first-cycle approvals in this category is only 40%, meaning there is a significant chance of a Complete Response Letter (CRL) or delay [verified base rate].
- What would move this number most. Whether the FDA will issue a Complete Response Letter (CRL) or approve the drug by the 12 December 2026 PDUFA date, as no specific regulatory signals (like an advisory committee recommendation) have been reported in the recent press.
2026-09-22 09:06 48% 5 article(s) on file · gemini-3.5-flash
Reasons not recorded for this revision (detailed history has only been kept since recently).