Diroximel fumarate linked to lower rate of severe infection in MS

Key takeaways:

• Rates of severe infection were lower in all age groups of the diroximel fumarate cohort compared with anti-CD20s.
• COVID-19-related infection rates were lower in patients treated with diroximel fumarate.

Treatment with diroximel fumarate was linked to lower rates of severe infection compared with anti-CD20 monoclonal antibodies for adults of all ages with MS, according to a poster presented at ECTRIMS.

“Anti-CD20 monoclonal antibodies have demonstrated efficacy in people living with MS but are associated with increased infection risk compared with other MS disease-modifying therapies, which is a particular concern for older people with MS,” Jason P. Mendoza, PhD, study co-author and head of specialty care and medical evidence generation of U.S. Medical at Biogen, told Healio in an email.

Mendoza and colleagues compared the risk for severe infections and annualized relapse rate (ARR) among propensity-score–matched (PSM) patients with MS who received diroximel fumarate (DRF) vs. those who received anti-CD20 monoclonal antibodies. The analysis was further divided into age groups: patients younger than 45 years and those aged 45 years and older.

The study included data on 2,894 individuals aged 18 to 64 years from the Komodo Health Claims database who had claims between January 2016 to January 2024 . The patients were evenly split between age groups and treatment options. In each treatment group, there were 683 patients aged younger than 45 years and 764 aged 45 years and older.

The primary outcome was the number of claims for infection-related encounters, particularly in patients with a severe infection that required either hospitalization or IV antibiotic administration. Infection outcomes were stratified by severity, location and link to COVID-19. The secondary outcome was annualized infection rate, which was defined as the sum of total observed infection events divided by patient-years within each of the four classifications.

At 24 months, the results showed a lower rate of severe infection in both younger (7.4% vs. 14.9%) and older individuals (12.8% vs. 20.5%) treated with DRF vs. anti-CD20s, with no significant difference in annualized relapse rates.

In addition, annualized rates of severe infection were lower in both younger (rate ratio = 0.51) and older groups (RR = 0.77) in the DRF group compared with the anti-CD20 group, with statistical significance in the younger division.

Data further showed that annualized infection rates, considering COVID-19 encounters, were significantly lower in both younger and older DRF treatment strata, while the researchers found non-COVID-19 infection rates did not differ between age groups.

“Given the risk of severe infections, particularly in older people with MS who have higher rates of infection-related hospitalization and mortality, this study provides important considerations for treatment in these populations,” Mendoza told Healio.