Some AAV Patients May Not Respond to Rituximab, Study Finds

About 12% of patients with antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis  (AAV) stopped responding to treatment from rituximab within 3 months, according to the results of a retrospective cohort study published in the journal Joint Bone Spine. More than half of these patients (64%) had heightened disease activity defined by the Birmingham vasculitis score (BVAS) of equal to or greater than 3.

“These patients presented more often with a localized disease and were less often treated with initial methylprednisolone pulse and sulfamethoxazole trimethoprim,” the report read.

The French investigators enrolled 116 patients (69 men and 47 women) newly diagnosed with AAV or relapsing AAV between 2010 and 2020. The median age of the participants was 56 years. All participants received induction therapy with rituximab. The primary endpoint was rituximab resistance at 3 months, defined by an increased BVAS score or uncontrolled disease flare.

A total of 14 patients (12%) showed resistance to rituximab at 3 months. Of these, 9 patients had severe disease, 8 patients presented new/ worsening symptoms or no clinical improvement after 1 month, and 6 patients had flares at some point during the 3 months of treatment.

“Patients with rituximab resistance at 3 months had a greater proportion of localized disease (43% vs 18%, P<0.05). They were also less often treated by initial methylprednisolone pulse (21% vs 58%, P<0.01),” the investigators noted.

All patients were in remission at 6 months.

Reference:
Machet T, Quémeneur T, Ledoult E et al. Rituximab resistance at 3 months of induction therapy in newly diagnosed or relapsing ANCA-associated vasculitis: A French multicentre retrospective study in 116 patients. Joint Bone Spine. 2023; 90(5). DOI: https://doi.org/10.1016/j.jbspin.2023.105591