AnaptysBio Touts Positive Top-Line Phase III Data for Pustular …

AnaptysBio has announced results from its Phase III GEMINI-1 trial, showing that the lgG4 antibody imsidolimab achieved its main goal in patients with a rare skin disorder linked to generalized pustular psoriasis.

Imsidolimab is an IgG4 antibody that inhibits the function of the interleukin-36 receptor (IL-36R), a signaling pathway within the immune system involved in the pathogenesis of inflammatory diseases, such as generalized pustular psoriasis (GPP). The condition also covers large areas of the body and causes fever, shivers, intense itching and joint pain.

The topline data showed that the registration trial reached the primary endpoint at week 4 after a single dose of imsidolimab, demonstrated by the clearing of pus-filled blisters in patients. In the study, 53.3% of patients who received a single dose of 750mg IV imsidolimab achieved GPPPGA 0/1 (clear or almost clear) at week four (primary endpoint), compared to 13.3% of patients on placebo. In addition, the drug showed favorable safety in patients without any serious adverse events reported.

“GPP is an unpredictable and potentially life-threatening skin disease with systemic symptoms,” Hervé Bachelez, a professor of dermatology at the Hôpital Saint-Louis in Paris, said in a statement. “Achieving positive top-line results utilizing the GPPPGA composite endpoint in this well conducted, randomized controlled, global trial, along with a compelling safety profile, represents the potential for a single dose of imsidolimab to predictably provide relief for patients living with this burdensome disease.”

The trial featured 45 randomized patients—15 per arm—that received either a single intravenous dose of anti-IL-36R antibody imsidolimab or placebo. The placebo patients who were worsening or not improved after day eight were eligible for rescue therapy and crossover into the GEMINI-2 Phase III trial, thus able to receive a single infusion of 750mg IV imsidolimab. Four weeks later, 53.3% of patients on the drug had a score of clear or almost clear, as measured on a physician assessment scale.

AnaptysBio intends to submit marketing application for the drug to the FDA by the third quarter of 2024.

“We intend to out-license imsidolimab with this compelling and competitive dataset to bring this therapy to patients living with this highly morbid condition and reallocate the potential proceeds of a transaction to further invest in the broad development of our best-in-class immune cell modulators, including our checkpoint agonists, in autoimmune and inflammatory diseases,” AnaptysBio CEO Daniel Faga said in a statement.