FDA approves imsidolimab for generalized pustular psoriasis on or before the disclosed PDUFA goal date of 2026-12-12

The proposition

What was claimed

The FDA takes an approval action on Vanda Pharmaceuticals' Biologics License Application for imsidolimab (proposed name Quimilza) for the treatment of generalized pustular psoriasis, with an approval action date on or before 2026-12-12, the target action date disclosed in AnaptysBio's Form 10-KT filed 2026-09-21.

Authority

US Food and Drug Administration (FDA), Center for Drug Evaluation and Research (CDER) (US)

Target rungA step on the 12-rung ladder: rungs 1 to 4 are the evidence moving, rungs 5 to 7 are a guideline body, regulator, or payer acting. The ladder, rung by rung

Rung 6: Regulatory action — Label/indication change, approval action, REMS modification, or withdrawal by FDA, EMA, PMDA, Health Canada, etc.

Forecast classThe group of like forecasts this one is counted and scored with, such as FDA actions by their goal dates

FDA action by goal date

Scope

Generalized pustular psoriasis

The clock

Dates that constrain the record

resolution window

Today

Evidence cutoff2026-10-15 Registered2026-10-15 Window opens2026-10-16 Deadline2026-12-12

Evidence cutoff

2026-10-15

Registered

2026-10-15

Window opens

2026-10-16

Deadline

2026-12-12

Evidence cutoff

2026-10-15
Nothing after this date informed the estimate.

Registered

2026-10-15
Frozen and hashed.

Resolution window

2026-10-16 → 2026-12-12
When the adjudicator can read the outcome.

Event by

2026-12-12
The final qualifying action date; the frozen resolution rule defines what counts. Add to calendar

ledger 41c59f846806fdd51750606007d7d5861960bd532e5b23f07b3ba897880a15b7 Copy · operator record jc-1792036248042-45adc42c

Resolution

The rule that settles the forecast

Resolves YES if the openFDA Drugs@FDA records returned by https://api.fda.gov/drug/drugsfda.json?search=openfda.generic_name:%22imsidolimab%22&limit=100 and by https://api.fda.gov/drug/drugsfda.json?search=products.active_ingredients.name:%22IMSIDOLIMAB%22&limit=100, read together (openFDA does not always fill the generic-name field for a new application), contain an application whose ORIG submission has submission_status AP and a submission_status_date on or before 2026-12-12, and the Drugs@FDA approval letter or label for that application names generalized pustular psoriasis in its indication, with Vanda or a Vanda subsidiary as applicant. An approval for a narrower generalized pustular psoriasis population than the applicant sought still resolves YES. Resolves NO if no approval action is dated on or before 2026-12-12: a complete response letter, a goal-date extension, withdrawal or no action. The goal date is frozen as disclosed at the cutoff; a later extension does not move it, and an approval dated after 2026-12-12 resolves NO as occurred_after_deadline. 2026-12-12 is a Saturday; an approval action dated that day still counts. Read no earlier than 2026-12-26. If openFDA has not refreshed by then, the Drugs@FDA web record (https://www.accessdata.fda.gov/scripts/cder/daf/, searched by the name imsidolimab) governs. If neither lists the product, FDA's Purple Book (https://purplebooksearch.fda.gov/, searched by imsidolimab) governs for the licensure date, with the approval letter for the indication. The application number was not public at the cutoff, so the rule reads by name; a suffix on the nonproprietary name or a proprietary name does not change the identification. Resolves unresolvable only if none of these sources can be read after the read floor. Resolves VOID, with the reason recorded, only if FDA withdraws every public record of approval actions named above without an equivalent public successor, so that no approval date for this product can be read; while any of them publishes it, the rule stands.

Source the rule names: https://api.fda.gov/drug/drugsfda.json?search=openfda.generic_name:%22imsidolimab%22&limit=100, https://api.fda.gov/drug/drugsfda.json?search=products.active_ingredients.name:%22IMSIDOLIMAB%22&limit=100, https://www.accessdata.fda.gov/scripts/cder/daf/, https://purplebooksearch.fda.gov/

Readers: Resolver A, clinical methodology; Resolver B, payer evidence. The same two reader roles are assigned to every forecast registered so far.

What this record will show once it resolves

Frozen covariatesThe facts about the evidence and the authority's process that were frozen with the forecast at its cutoff

The state of the record at the cutoff

Recorded as they stood on 2026-10-15, including the one field whose value was unknown then. It is left unknown rather than filled in.

review pathway

unknown — not stated in the archived sources (BLA submitted December 2025 with a December 12, 2026 target date, consistent with a standard review — drafter's understanding from dates, unverified); FDA Orphan Drug Designation for GPP (SRC-004)

submission type

original BLA (SRC-001)

evidence class

two Phase 3 trials: GEMINI-1 (randomized, placebo-controlled, single IV dose) and GEMINI-2 (randomized maintenance in GEMINI-1 responders) (SRC-004)

pivotal n

GEMINI-1: 45 patients; GEMINI-2: 16 GEMINI-1 responders re-randomized (SRC-004)

endpoint type

GEMINI-1 primary endpoint: GPPPGA 0/1 (clear or almost clear) at Week 4 — 53% (750 mg IV) vs 13% placebo, p=0.0131 (SRC-004)

approved competitors in class

SPEVIGO (spesolimab, Boehringer Ingelheim), an anti-IL-36 receptor antibody approved for GPP (SRC-004; openFDA BLA761244 ORIG-1 approved 2022-09-01, SRC-006)

months since last guideline revision

not applicable — no guideline is the subject of this proposition

panel cycle position

not applicable — the act is an FDA approval action

sponsor request status

BLA submitted December 2025; accepted February 2026 (SRC-001)

odac referral

none announced in the archived sources

sponsor state change

AnaptysBio licensed global rights to Vanda on January 31, 2025 and now manages its Jemperli and Quimilza royalties as a virtual company (SRC-001)