What Is the Significance of New Data on Imsidolimab for GPP? With Neal Bhatia, MD

The US Food and Drug Administration (FDA)'s acceptance of a Biologics License Application (BLA) for imsidolimab, Vanda Pharmaceuticals' investigational interleukin (IL)-36 receptor inhibitor for generalized pustular psoriasis (GPP), could represent a meaningful step forward for a patient population with historically limited treatment options. The therapy is now under formal review as a potential addition to the emerging class of IL-36–targeted agents in dermatology.

Neal Bhatia, MD, a dermatologist at Therapeutics Clinical Research who’s location served as an investigator site for the development of spesolimab (Spevigo; Boehringer Ingelheim), the first IL-36 receptor inhibitor approved for GPP, referred to the development as "novel and well timed." Having another molecule targeting the same pathway, Bhatia highlighted, only adds clinical relevance.

"…[For] many of these patients who suffer in a prison of misdiagnosis or just not having options, this is really some game-changing stuff for them," Bhatia said.

Central to his enthusiasm are the GEMINI-1 and GEMINI-2 trial results, in which a single intravenous dose of imsidolimab led 53% of treated patients to achieve a Generalized Pustular Psoriasis Physician Global Assessment (GPPPGA) score of 0 or 1, suggesting clear or almost clear skin — by week 4, compared with 13% on placebo. Bhatia emphasized that rapid onset is particularly consequential in GPP, where flares can escalate to life-threatening complications including cardiovascular failure and sepsis.

The durability data may be equally compelling. Patients who continued into a roughly 2-year maintenance phase on monthly dosing experienced no disease flares in the active treatment arm, a finding Bhatia described as a significant quality-of-life advance for patients who, even in remission, live in fear of their next episode.

Bhatia also addressed a persistent clinical misconception: the tendency among some dermatologists to reach for IL-17 or IL-23 inhibitors in GPP given their established efficacy in plaque psoriasis. While cytokine pathway overlap exists, he was direct in distinguishing GPP's pathophysiology.

"…GPP is well established in an interleukin-36 milieu, where that cytokine is the main driver," Bhatia expressed. He pointed to the prominent role of neutrophils, reactive oxygen species, and tissue damage unique to IL-36 dysregulation. Targeting that pathway specifically, as both spesolimab and potentially imsidolimab do, is what Bhatia characterized as the key to not just resolving flares, but keeping the disease away.

The quotes contained in this interview summary were edited for clarity.

References

1. Smith T. FDA Accepts BLA for Imsidolimab as Generalized Pustular Psoriasis Treatment. HCPLive. February 25, 2026. Accessed March 10, 2026. https://www.hcplive.com/view/fda-accepts-bla-imsidolimab-generalized-pustular-psoriasis-treatment.

2. Vanda Pharmaceuticals Announces FDA Acceptance of Biologics License Application Filing for Imsidolimab for the Treatment of Generalized Pustular Psoriasis. Vanda Pharmaceuticals, Inc. February 25, 2026. Accessed March 10, 2026. https://www.prnewswire.com/news-releases/vanda-pharmaceuticals-announces-fda-acceptance-of-biologics-license-application-filing-for-imsidolimab-for-the-treatment-of-generalized-pustular-psoriasis-302696991.html.