Abstract: SA-OR046
Safety and Efficacy of Inebilizumab in IgG4-Related Disease: Subgroup Analysis from MITIGATE
Session Information
- Glomerular Diseases: Clinical Trial Results
October 24, 2026 | Location: Mile High Ballroom 4A, Convention Center
Abstract Time: 04:30 PM - 04:40 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Radhakrishnan, Jai, Columbia University, New York, New York, United States
- Stone, John H., Harvard Medical School, Boston, Massachusetts, United States
- Culver, Emma L., University of Oxford, Oxford, England, United Kingdom
- Khosroshahi, Arezou, Emory University, Atlanta, Georgia, United States
- Zhang, Wen, Peking Union Medical College Hospital, Beijing, China
- Della Torre, Emanuel, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Okazaki, Kazuichi, Kansai Ika Daigaku Kori Byoin, Neyagawa, Osaka Prefecture, Japan
- Tanaka, Yoshiya, University of Occupational and Environmental Health, Kitakyushu, Japan
- Löhr, Matthias, Karolinska Institutet, Stockholm, Stockholm County, Sweden
- Schleinitz, Nicolas, Aix-Marseille Universite, Marseille, Provence-Alpes-Côte d'Azur, France
- Dong, Lingli, Huazhong University of Science and Technology Tongji Medical College, Wuhan, Hubei, China
- Umehara, Hisanori, Nagahama City Hospital, Shiga, Japan
- Lanzillotta, Marco, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Wallace, Zachary, Amgen Inc, Thousand Oaks, California, United States
- Ebbo, Mikael, Aix-Marseille Universite, Marseille, Provence-Alpes-Côte d'Azur, France
- Webster, George, University College London, London, England, United Kingdom
- Martinez Valle, Fernando, Vall d’Hebron Hospital, Barcelona, Spain
- Bray, Sarah, Amgen Ltd, Cambridge, England, United Kingdom
- Cheng, Sue, Amgen Inc, Thousand Oaks, California, United States
- Perugino, Cory, Massachusetts General Hospital, Boston, Massachusetts, United States
- Nayar, Manu, Freeman Hospital, Newcastle upon Tyne, England, United Kingdom
- Rebours, Vinciane, Hopital Beaujon, Clichy, Île-de-France, France
- Rosen, Melissa, Amgen Inc, Thousand Oaks, California, United States
- Cimbora, Daniel, Amgen Inc, Thousand Oaks, California, United States
Background
Kidney and retroperitoneal involvement is common in IgG4-related disease (IgG4-RD). Inebilizumab (INEB), a B-cell depleting anti-CD19 antibody, demonstrated safety and efficacy in IgG4-RD in the randomized, placebo (PBO)-controlled Phase 3 trial MITIGATE trial. We report post hoc analysis of MITIGATE data to evaluate safety and efficacy in patients with baseline disease activity in the kidney.
Methods
Eligible patients had a history of ≥2 organs involved and had experienced a recent IgG4-RD flare that required glucocorticoid treatment during the screening period. Patients were randomized 1:1 to INEB or PBO and were treated on day 1, day 15, and week 26 of the 1-year randomized controlled period (RCP). Steroids were tapered to discontinuation at the end of RCP week 8, and other immunosuppressive therapy for IgG4-RD was prohibited during the study.
Results
At baseline, disease activity was evident in the kidney in 40 (29.6%) patients (INEB n=21; PBO n=19). INEB markedly reduced the risk of flare relative to PBO (2/21 patients with flares in the INEB group vs 12/19 in the PBO group; HR=0.08, nominal p=0.0012). Annualized flare rate was also reduced by INEB relative to PBO in the kidney subgroup (0.09 INEB vs 0.91 PBO, rate ratio 0.10, nominal p=0.002). The proportion of patients achieving flare-free, corticosteroid-free complete remission was higher with INEB vs PBO (57.1% vs 21.1%; odds ratio 5.08, nominal p=0.0281). Cumulative steroid use for IgG4-RD disease control during the 12-month RCP was substantially reduced with INEB vs PBO in the kidney group (mean, 58 mg vs 1755 mg prednisone equivalent per patient, nominal p=0.0036; Table 1). Incidences of treatment-emergent, serious, and Grade ≥ 3 adverse events in the kidney group were similar to the overall study population, with no adverse effects on renal function and no deaths reported.
Conclusion
Safety and efficacy findings of INEB in MITIGATE patients with active IgG4-RD kidney involvement are similar to the overall study population, demonstrating the utility of CD19-targeted B-cell depletion by INEB in patients with renal IgG4-RD.
Acknowledgment
Study and abstract were funded by Amgen Inc. with medical writing support provided by Swati Ghatpande, PhD, Amgen Inc.
Funding
- Commercial Support – Amgen