Biosimilar Rituximab in ANCA-Associated Vasculitis Compared to the Originator: A Multicenter Cohort Study

Area of Science:

• Rheumatology
• Immunology
• Pharmacology

Background:

• Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are severe autoimmune diseases.
• Rituximab is a key biologic therapy for GPA and MPA.
• The introduction of rituximab biosimilars necessitates evaluation of their comparative effectiveness and safety.

Purpose of the Study:

• To compare the six-month effectiveness and safety of rituximab biosimilars versus the originator in GPA and MPA patients.
• To assess outcomes in patients switching from rituximab originator to a biosimilar.

Main Methods:

• A cohort study included 207 adults with GPA or MPA receiving rituximab originator or biosimilar for induction or maintenance.
• Outcomes assessed at six months included remission, relapse, vasculitis damage, and serious adverse events (SAEs).
• A subgroup analysis examined patients switching from originator to biosimilar maintenance therapy.

Main Results:

• No significant differences in six-month remission rates were observed between rituximab originator and biosimilar induction groups (96% vs. 90%).
• All patients in the maintenance and switch groups achieved remission at six months.
• Similar rates of relapse, vasculitis damage, and SAEs were reported across all groups.

Conclusions:

• Rituximab biosimilars demonstrate comparable effectiveness and safety to the originator for induction therapy in GPA and MPA.
• No safety concerns were identified for patients initiating maintenance therapy or switching to biosimilars.
• These findings support the use of rituximab biosimilars in managing GPA and MPA.