Time to Relapse Following Rituximab Therapy in Rheumatoid Arthritis and Its Determinants: A Single-Center...

Area of Science:

• Rheumatology
• Immunology
• Pharmacology

Background:

• Rituximab (RTX), a CD20-targeting monoclonal antibody, is used for rheumatoid arthritis (RA) refractory to conventional and biologic therapies.
• Treatment response to RTX in RA can be transient, with relapses occurring after variable intervals.
• Time to relapse (TTR) quantifies the duration of RTX efficacy before RA disease recurrence.

Purpose of the Study:

• To evaluate the time to relapse (TTR) after the most recent rituximab (RTX) cycle in patients with rheumatoid arthritis (RA).
• To identify clinical, biological, and therapeutic factors associated with RTX treatment duration and relapse timing in RA patients.

Main Methods:

• A retro-prospective, single-center observational study of RA patients treated with RTX (2021-2025).
• Primary outcome: physician-assessed objective TTR post-RTX cycle. Secondary outcome: patient-reported relapse.
• Kaplan-Meier analysis for relapse-free survival; univariable and multivariable linear regression for factor identification.

Main Results:

• 97 RA patients included; median objective TTR was nine months (IQR 7-11), matching patient-reported TTR.
• One-year flare-free survival was 37.1%.
• Lower baseline swollen joint count (SJC) was independently associated with longer TTR in multivariable analysis (P=0.040).

Conclusions:

• The median TTR for RTX therapy in RA is approximately nine months.
• Baseline disease activity, specifically SJC, is a key factor influencing relapse timing after RTX.
• Prospective studies are needed to confirm findings and guide individualized RTX retreatment strategies in RA.