Achieving GC-Free IgG4-Related Disease Remission With Rilzabrutinib, with John Stone, MD, MPH

Rilzabrutinib demonstrated high rates of remission in people with IgG4-related disease despite a short glucocorticoid (GC) tapering period, in new data from a phase 2 study.

These findings were presented at the European Alliance of Associations for Rheumatology (EULAR) Congress 2025 in Barcelona, Spain, taking place June 11-14, 2025, by investigator John Stone, MD, MPH, professor of medicine at Harvard Medical School and Edward A. Fox Chair in Medicine at the Massachusetts General Hospital.

HCPLive spoke with Stone to learn more about rilzabrutinib and its potential advantages for treating IgG4-related disease, including the fact that it is an oral drug, which offers access and safety benefits compared to intravenous infusions. He emphasized the high, 70% rate of remission seen in study participants at week 52 without any additional treatments like GCs or immunosuppressants. Furthermore, he highlighted the very short steroid taper period, with participants discontinuing their steroids after only 1 month of rilzabrutinib treatment.

“Remember that when we use B-cell depletion strategies, whether rituximab as in the past sometimes or inebilizumab now, patients receive 100 milligrams of methylprednisolone with each of their infusions. So that contributes also to the efficacy of that approach. With the rilzabrutinib trial, there was very little steroid at the beginning, and it was tapered off completely at 1 month,” Stone said.

Participants also experienced clinically meaningful improvements in disease activity were observed at week 52 as assessed by ≥2 point reductions in IgG4-RD responder index, with improvements evident as early as week 12 and sustained at week 52. The safety profile of rilzabrutinib was consistent with that in previous studies, with no new safety signals observed. Diarrhea, COVID-19, dizziness, dry mouth and nausea were among treatment-emergent adverse events reported by over 10% of patients.

REFERENCE

Media Update: EULAR: rilzabrutinib data in IgG4-related disease show reduction in flares and key disease markers; earns Fast Track designation in the US. News release. Sanofi. June 12, 2025. https://www.sanofi.com/en/media-room/press-releases/2025/2025-06-12-08-30-00-3098093