Hansoh Pharmaceutical Group Co., Ltd. (03692.HK) announced that the U.S. FDA has granted Breakthrough Therapy Designation (BTD) to Inebilizumab for the treatment of Immunoglobulin G4-related disease (IgG4-RD). This designation follows positive results from the Global Phase 3 MITIGATE study, which will be presented at the American College of Rheumatology (ACR) Convergence 2024, held in Washington, D.C., Nov. 14–19.
MITIGATE Study Overview
The MITIGATE trial (NCT04540497) is the first randomized, double-blind, placebo-controlled study in IgG4-RD, conducted at 80 sites across 22 countries, including China. The study established the efficacy and safety of CD19+ B cell depletion with Inebilizumab in managing IgG4-RD.
Key Findings
- Flare Reduction: Inebilizumab reduced the risk of IgG4-RD flare by 87% compared to placebo (Hazard Ratio 0.13, p<0.001) during the 52-week period. Only 7 of 68 participants treated with Inebilizumab experienced a flare versus 40 of 67 in the placebo group.
- Annualized Flare Rate: Patients receiving Inebilizumab had an annualized flare rate of 0.10 compared to 0.71 for placebo (p<0.001).
- Complete Remission: 57.4% of patients achieved flare-free, treatment-free remission at Week 52 with Inebilizumab, versus 22.4% with placebo (p<0.001).
- Corticosteroid-Free Remission: 58.8% of patients on Inebilizumab achieved corticosteroid-free remission compared to 22.4% on placebo (p<0.001).
- Glucocorticoid Use: 89.7% of patients treated with Inebilizumab required no glucocorticoids during the placebo-controlled period, compared to 37.3% of placebo patients. Post-Week 8, Inebilizumab patients used 10 times fewer glucocorticoids than placebo patients.
The unique mechanism of action of Inebilizumab, which rapidly depletes peripheral B cells and lowers disease biomarkers, was also confirmed.
Safety Profile
The safety results align with the established profile of Inebilizumab. Common adverse events included COVID-19, lymphopenia, urinary tract infection, and headache.
Regulatory Progress
The U.S. FDA granted Breakthrough Therapy Designation in August 2024, based on the MITIGATE study results. Regulatory filing activities are in progress. Simultaneously, the study data was published in the New England Journal of Medicine.
Hansoh Pharma holds exclusive licensing rights and oversees regulatory and commercial activities for Inebilizumab in mainland China, Hong Kong, and Macau.
