Treating rheumatoid arthritis patients with lower doses of rituximab for long-term maintenance reduced the risk of serious infections and saved money, based on data from approximately 1,200 patients in a French registry.
In a study published in Rheumatology, Julien Henry, MD, of Institut pour la Sante et la Recherche Medicale, Paris, and colleagues reviewed data from 1,278 patients; 1,093 (85.5%) received a standard dose of rituximab, and 185 (14.5%) received a reduced dose for maintenance therapy. A standard dose was 1,000 mg per infusion given in two infusions 2 weeks apart), and a reduced dose was 500 mg per infusion given in two infusions 2 weeks apart.
After 5 years, maintenance was 55.5% in the standard group and 53.8% in the reduced group; with no significant difference (hazard ratio, 1.03). However, the cumulative dose for retreatment was 39% less in the reduced group (1.4 g per year vs. 2.3 g per year), “which is greatly cost effective,” the researchers wrote.
In addition, the rate of serious infections was significantly lower in the reduced-dose group, compared with the standard-dose group (2.2 per 100 patient-years vs. 4.1 per 100 patient-years; adjusted hazard ratio = 0.50).
“Of note, factors associated with risk of serious infection, such as baseline low gamma globulin or IgG levels, chronic lung or cardiac disease, and extra-articular involvement, did not differ between groups,” the researchers said.
The study findings were limited by several factors including the observational design and lack of data on certain RA outcome measures such as radiographic progression and function, the researchers noted. However, the results support data from similar studies and suggest that a lower dose of rituximab for retreatment of RA “did not alter the maintenance of the treatment at 5 years and is associated with a significant lower rate of serious infections,” they said.
Dr. Henry had no financial conflicts to disclose. Several coauthors disclosed relationships with multiple drug companies, but the study received no specific funding from any of these companies.
SOURCE: Henry J et al. Rheumatology. 2017 Dec 15. doi: 10.1093/rheumatology/kex446.