In early October 2023, the clinical-stage biotechnology company AnaptysBio, Inc. shared, via a news release, that positive top-line results were available from the Phase 3 GEMINI-1 study. Within the study, researchers aimed to evaluate the safety and effectiveness of imsidolimab in treating individuals with generalized pustular psoriasis (GPP), a rare and often severe form of psoriasis. Researchers assessed improvements in pustulation and other symptoms using the Generalized Pustular Psoriasis Physician Global Assessment.
Imsidolimab is a humanized antibody designed to reduce overactive and unregulated IL-36R signaling. Since the top-line results of the Phase 3 GEMINI-1 trial have been shared, AnaptysBio is now planning to move forward with the GEMINI-2 study. The study will include individuals who completed the GEMINI-1 trial. Participants will receive 200mg imsidolimab administered subcutaneously each month. Researchers hope to understand how imsidolimab impacts the prevalence of GPP flares over a 3-year period.
Insights on GPP from GEMINI-1
Altogether, 45 participants enrolled in the study. Participants were divided into three groups. One group received a single dose of 300mg imsidolimab, one received a single dose of 750mg imsidolimab (administered subcutaneously), and the last group received a placebo. After a 4-week period, researchers found that:
Imsidolimab was relatively safe and well-tolerated by participants. There were no severe adverse reactions, no cases of Guillain-Barré syndrome, no heightened level of infections, and no infusion-related treatment reactions. One individual treated with imsidolimab had non-neutralizing anti-drug antibodies.
53.3% of participants who took the 750mg dose (8 participants) achieved nearly clear or fully clear skin by the end of the 4-week period. Only 13.3% (2 participants) in the placebo group achieved the same results.
Ten participants who received the placebo chose to continue treatment in the GEMINI-2 study, where they were given a rescue dose of this therapy.
In the future, in addition to continued studies, AnaptysBio plans to license the therapy.
What You Should Know about Generalized Pustular Psoriasis (GPP)
Also known as: von Zumbusch psoriasis
As explained above, generalized pustular psoriasis is a rare and severe form of psoriasis that most often occurs in people between ages 40-70, although cases can occur in people of other age groups. People with GPP have flares in which pustules form over large swathes of the body, as well as periods of remission and clear skin. GPP flares may result from corticosteroid treatment withdrawal, pregnancy, infections, or stress; people may also be predisposed to GPP due to mutations in IL36RN or CARD14. This condition is slightly more common in females than males, and a slight majority of people with GPP also have plaque psoriasis.
GPP flares can cause life-threatening complications such as rapid drops in blood pressure. If you have GPP and are experiencing a flare, please contact your physician as soon as possible. In addition to pustule formation, people with GPP may present with:
- Fever and chills
- A rapid pulse
- Joint pain
- Muscle weakness
- Nausea
- Fatigue
- Headache
- Large areas of skin redness, itchiness, dryness, scaliness, and/or tenderness
- Cheilitis
- Tongue fissures
