John Stone, MD, MPH: Inebilizumab Efficacious for IgG4-Related Disease in MITIGATE Study

CD19-targeted B cell depletion with inebilizumab was efficacious and well-tolerated in patients with IgG4-related disease and reduced the risk of flares by 87% compared to placebo.

Updated data from the phase 3 MITIGATE study were presented by primary investigator John Stone, MD, MPH, director, clinical rheumatology at Mass General Hospital, and Professor of Medicine at Harvard Medical School, and founder and executive chairman at The IgG4ward! Foundation, at the American College of Rheumatology (ACR) Convergence 2024, held November 14-19 in Washington, DC.

“IgG4-related disease wasn't even recognized to be a unique disease entity until 2003 so a lot of the unmet need stems from lack of recognition of the disease still, but the disease has been recognized increasingly for the past 2 decades. [So, there has been] a huge gap in therapies until now. And even now, the cornerstone of therapy for treating this disease is steroids,” Stone said in an interview with HCPLive at the meeting.

The MITIGATE study included 135 participants randomized to and receiving at least one dose of inebilizumab (n=68) or placebo (n=67). The study met its primary endpoint, with the inebilizumab group having a hazard ratio of flares of 0.13 (95% CI, 0.06-0.28; P <.0001) compared to placebo. Three (4.4%) participants receiving inebilizumab and 5 (7.5%) receiving placebo experienced infusion related reactions. Rates of opportunistic infections were 8.8% (n = 6) and 3.0% (n = 2), respectively.

“We have used rituximab off-label for the past years, but it's an unapproved therapy, and that's the real challenge for many patients who just cannot get this therapy. In the United States, we're able to get it more often… but there are many places in the rest of the world where the therapy is just not available. So having an approved therapy [would be] a huge advance for people with this condition,” Stone said.

REFERENCE

Stone J, Culver E, Khosroshahi A, et al. A Phase 3, Randomized, Double-Blind, Multicenter, Placebo-Controlled Study of Inebilizumab in IgG4-Related Disease (MITIGATE): Primary Efficacy and Safety Findings. Presented at: ACR Convergence 2024, November 14-19; Washington, DC.