AnaptysBio Announces British Journal of Dermatology Publication of Imsidolimab (IL-36R) Previously Reported Phase 2 GALLOP Data in Generalized Pustular Psoriasis (GPP)

• Rapid and sustained efficacy demonstrated in GPP patients after only a single dose, achieving primary endpoint at Week 4
• Flare control sustained on monthly subcutaneous doses through Week 16
• Imsidolimab was generally safe and well tolerated with low overall ADA incidence
• Top-line GEMINI-1 Phase 3 trial data expected in Q4 2023

SAN DIEGO, May 02, 2023 (GLOBE NEWSWIRE) -- AnaptysBio, Inc. (Nasdaq: ANAB), a clinical-stage biotechnology company focused on delivering innovative immunology therapeutics, today announced the publication of data from the open-label, single-arm Phase 2 GALLOP study evaluating the efficacy, tolerability and safety of imsidolimab, its investigational anti-interleukin-36 receptor (IL-36R) IgG4 antibody for the treatment of generalized pustular psoriasis (GPP), in the British Journal of Dermatology. Patients with GPP who received a single dose of imsidolimab demonstrated a rapid and sustained improvement of symptoms and pustular eruptions of GPP flare within days after initiating treatment.

A potentially debilitating and life-threatening systemic inflammatory skin disease, GPP affects an estimated 15,000 to 37,000 individuals in the U.S. It is characterized by intermittent and/or recurrent episodes, or flares, of widespread pustular eruptions that can be accompanied by fever, nausea, pain, anorexia and general malaise.

“We remain excited and quite pleased with the dramatic effects demonstrated by imsidolimab’s Phase 2 efficacy and safety data and the potential benefit to patients suffering with life threatening inflammatory GPP,” said Paul F. Lizzul, chief medical officer of AnaptysBio. “We look forward to sharing the top-line data on the efficacy, safety and tolerability of a single dose IV infusion of imsidolimab in moderate-to-severe GPP patients from the ongoing GEMINI-1 Phase 3 trial in Q4 2023, whereafter we plan to out license the program prior to a potential FDA approval.”

In the Phase 2 GALLOP study, a total of eight adult patients with GPP flare were enrolled and received a 750mg IV dose of imsidolimab and six patients were evaluable at both Day 29 and Day 113 and who also completed the study. Clinical responses were observed as early as Day 3, most rapidly for pustulation relative to other visible manifestations of GPP, with continued and consistent improvement across multiple efficacy assessments at Day 8, Day 29, and through Day 113. Of the six patients evaluable on Day 29, all achieved the primary endpoint of clinical response on the clinical global impression scale (CGI). Additionally, the GPP Physician Global Assessment (GPPPGA) scale was implemented by protocol amendment during the trial and was assessed in four of the eight enrolled patients, where zero (clear) or one (almost clear) response was achieved in 50% (two) patients at Week 4. Six of eight patients received a monthly 100mg subcutaneous dose of imsidolimab beginning at Week 4 and continued through Week 12. At Week 16, 75% (three of four) of evaluable patients were responders (clear or almost clear) on the GPPPGA scale.