AnaptysBio announces publication of data from Phase 2 GALLOP study

AnaptysBio 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 IgG4 antibody for the treatment of generalized pustular psoriasis, 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. "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. Additionally, the GPP Physician Global Assessment scale was implemented by protocol amendment during the trial and was assessed in four of the eight enrolled patients, where zero or one response was achieved in 50% 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% of evaluable patients were responders on the GPPPGA scale. Imsidolimab was generally well-tolerated. Most treatment-emergent adverse events were mild to moderate in severity. Initial top-line Phase 2 study results were presented at European Academy of Dermatology and Venerology Congress in October 2021.