FDA Accepts BLA for Imsidolimab as Generalized Pustular Psoriasis Treatment

The US Food and Drug Administration (FDA) has accepted for review a Biologics License Application (BLA) for imsidolimab as a treatment for individuals with generalized pustular psoriasis (GPP).1

This February 25 announcement by Vanda Pharmaceuticals, Inc. also refers to the FDA’s Prescription Drug User Fee Act (PDUFA) target date for imsidolimab as December 12, 2026. GPP itself is known to be an uncommon, persistent, and potentially fatal autoinflammatory skin condition, leading many of those with the disease to develop diffuse redness, widespread sterile pustules, and systemic manifestations such as fever and fatigue.2

"The acceptance of the BLA filing for imsidolimab marks a critical milestone in our efforts to bring this innovative therapy to patients suffering from GPP," Mihael H. Polymeropoulos, MD, president, CEO, and Chairman of the Board of Vanda Pharmaceuticals, said in a statement.1 "Imsidolimab builds on our growing expertise in rare orphan disorders and our anti-inflammatory portfolio.”

GPP’s underlying biology has been examined following several key advances in genetic research, including its classification under OMIM #614204. Many consider dysregulation of the interleukin (IL)-36 signaling cascade as a key element of the skin disease’s pathogenesis. Among many individuals in whom a single-gene cause has been identified, pathogenic variants in IL36RN, the gene encoding the IL-36 receptor antagonist, are pointed to as responsible for their insufficient control of IL-36–mediated inflammation.

Flares of GPP can be life-threatening if they are not treated, as the condition’s potential serious symptoms can lead to complications such as cardiovascular failure or sepsis.2 To address GPP, imsidolimab was designed as a fully human IgG4 monoclonal antibody to block IL-36 receptor signaling in such patients.

Imsidolimab therapy, by inhibiting this pathway, is intended to counteract the excessive IL-36 activity described as driving GPP-related inflammation. If imsidolimab receives an FDA approval, it may provide a new option for those impacted by this severe but rare skin condition, where medication options remain limited. The medication’s development program has included multinational clinical trials conducted across such countries as the US, Spain, France, Malaysia, Georgia, Morocco, and more.

During the pivotal GEMINI-1 and GEMINI-2 studies, investigators found a single intravenous administration of imsidolimab led to rapid improvements in skin disease. By the 4-week mark, the GEMINI-1 and 2 investigators found 53% of treated patients achieved a Generalized Pustular Psoriasis Physician Global Assessment (GPPPGA) score of 0 or 1. Such a score suggests clear or almost clear skin. This 53% of patients was compared with only 13% of those on placebo.

Individuals who continued into an approximately 2-year maintenance phase and were provided with monthly dosing maintained clinical benefit. Additionally, the GEMINI team found no disease flares reported in the active treatment arm during this period. The investigational therapy was generally shown to be both well tolerated and linked with a low rate of anti-drug antibody formation, a factor that may differentiate it from certain existing medications.

Vanda is marking the FDA’s acceptance of the application during Rare Disease Week on Capitol Hill, held from February 24 - 26. This event is focused on the advancement of innovation and access to therapies for orphan diseases such as GPP.

“Imsidolimab represents a precision medicine approach targeting a disorder with a known genetic cause using a fully humanized monoclonal antibody against the IL-36 receptor,” Polymeropoulos said in a statement.1 “We look forward to potential FDA approval and leveraging our commercial infrastructure to address this debilitating condition."

References

1. 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. 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.

2. Rivera-Díaz R, Daudén E, Puig L, et al. Generalized Pustular Psoriasis: A Review on Clinical Characteristics, Diagnosis, and Treatment. Dermatol Ther (Heidelb). 2023 Mar;13(3):673-688. doi: 10.1007/s13555-022-00881-0. Epub 2023 Jan 13. PMID: 36635445; PMCID: PMC9836924.