Abstract: SA-OR33
Antibodies Anti-Rituximab Do Not Affect Response to Rituximab in Idiopathic Nephrotic Syndrome
Session Information
- Glomerular Diseases: Trials, Prognostic Markers, and Podocyte Biology
November 06, 2021 | Location: Simulive, Virtual Only
Abstract Time: 04:30 PM - 06:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Angeletti, Andrea, Istituto Giannina Gaslini, Genova, Liguria, Italy
- Bruschi, Maurizio, Istituto Giannina Gaslini, Genova, Liguria, Italy
- Lugani, Francesca, Istituto Giannina Gaslini, Genova, Liguria, Italy
- Colucci, Manuela, Ospedale Pediatrico Bambino Gesu, Roma, Lazio, Italy
- Vivarelli, Marina, Ospedale Pediatrico Bambino Gesu, Roma, Lazio, Italy
- Emma, Francesco, Ospedale Pediatrico Bambino Gesu, Roma, Lazio, Italy
- Caridi, Gianluca, Istituto Giannina Gaslini, Genova, Liguria, Italy
- Verrina, Enrico E., Istituto Giannina Gaslini, Genova, Liguria, Italy
- Ghiggeri, Gian Marco, Istituto Giannina Gaslini, Genova, Liguria, Italy
Background
Previous studies reported how infusion of the chimeric anti-CD20 rituximab results in production of antibodies anti-rituximab, that may limit the efficacy of further infusions. Among other reasons, the reduced immunogenicity of fully humanized anti-CD20 antibodies should increase their efficacy. In a randomized clinical trial, we compared the efficacy of ofatumumab vs. rituximab in children and young adults with steroid dependent nephrotic syndrome. As secondary endpoints, we evaluated possible role of anti-CD20 rituximab.
Methods
We randomized 140 children treated with single infusion of rituximab or ofatumumab, with a follow up of 24 months. We measured anti-rituximab antibodies IgG at the enrolment in 64/140 (46%) patients who have previously received rituximab and at 6 months in patients in the rituximab arm. Median time of the previous rituximab was 36 (12-51) months before enrolment.
Results
As primary endpoint, ofatumumab was not superior to rituximab in maintaining remission (Fig 1a). Serum anti-rituximab IgG were undetectable at baseline in 64 participants who had previously received rituximab. Six months following rituximab infusion, anti-rituximab antibody levels increased in 14 (42%) of the 33/64 patients who were randomized in the rituximab arm (Fig 1b). Among patients with relapse in rituximab arm, the efficacy of a second infusion of rituximab, infused in accordance with the protocol, was not affected by the presence of anti-rituximab antibodies (Fig 1c).
Conclusion
Previous exposure to rituximab results in production of anti-rituximab antibodies, which persist for a limited time. Presence of circulating anti-rituximab antibodies does not affect response to rituximab in steroid dependent nephrotic syndrome.