Frexalimab (SAR441344; Sanofi), an anti-CD40L monoclonal antibody, showed a sustained reduction of disease activity as well as favorable tolerability after approximately 1 year of treatment for relapsing multiple sclerosis (MS), according to data presented at the American Academy of Neurology 2024 Annual Meeting in Denver, Colorado. The results from the study were previously published in The New England Journal of Medicine.1,2
“These 48-week data showed that treatment with frexalimab resulted in further decreases in the number of lesions and a sustained reduction in disease activity. The preliminary clinical results are promising with a very low annual relapse rate. This strengthens the rationale for targeting CD40L in MS and supports further development of frexalimab as a potential high-efficacy therapy in relapsing MS,” said Patrick Vermersch, MD, PhD, from the University of Lille in France, in a press release.1
The study was a phase 2 randomized, double-blind, placebo-controlled study evaluating frexalimab for patients with relapsing MS. Individuals randomly received either a high dose of frexalimab at 1200 mg intravenously every 4 weeks, with an 1800 mg loading dose; a low dose of frexalimab at 300 mg subcutaneously every 2 weeks, with a 600 mg loading dose; or the placebo for 12 weeks, according to the press release. The primary end point included the reduction in new gadolinium-enhancing T1 magnetic resonance imaging (MRI) brain lesions at 12 weeks, and secondary end points included additional MRI-based efficacy, safety, tolerability, and pharmacokinetics of the drug.1
After the 12 weeks, patients receiving the placebo switched to one of the frexalimab arms for the open-label part B, which is currently still ongoing.1
According to the results at week 48, 96% of individuals who continued receiving the high dose were free of gadolinium-enhancing T1 lesions and 87% of individuals were lesion-free. Further, from those who switched from placebo to either the high or low dose experienced declines at week 24, with 90% and 92% free of gadolinium-enhancing T1 lesions at week 48, respectively.1
Gadolinium-enhancing T1 lesions were low among those who continued receiving frexalimab and continued to decline for those who switched from the placebo to the study drug at week 12. Additionally, the number and volume change of either new or enlarging gadolinium-enhancing T2 lesions remained low for all treatment groups through week 48. Investigators reported that the lymphocyte counts were stable for patients.1
Those who continued receiving high-dose frexalimab experienced lower annual relapse rate (ARR) at 0.04 over the 48-week treatment period, with approximately 96% being relapse free. For those receiving the low dose, there was an ARR of 0.22. For individuals switching to high and low doses, the ARR was 0.09 and 0.40, respectively, through 48 weeks, according to the press release.1
Key Takeaways
- Frexalimab treatment resulted in a continued decrease in lesions and disease activity over nearly 1 year.
- The study observed very low annual relapse rates in patients receiving frexalimab.
- The drug was well-tolerated with common side effects like those experienced with other medications.
Furthermore, frexalimab was generally well tolerated, with the most common adverse events among all subgroups of patients with nasopharyngitis, headache, and COVID-19, according to the results.1
“Frexalimab represents a novel potential first-in-class treatment mechanism in [MS] designed to tackle the aspects of this disease where unmet medical needs still exist,” Erik Wallström, MD, PhD, global head of neurology development at Sanofi, said in the press release. "We are applying our deep expertise to address the full spectrum of neuroinflammation and neurodegeneration to improve the lives of people living with multiple sclerosis."1
References
New 48-week frexalimab phase 2 data support potential for high sustained efficacy in multiple sclerosis. News release. Sanofi. April 17, 2024. Accessed April 19, 2024. https://www.sanofi.com/en/media-room/press-releases/2024/2024-04-17-05-00-00-2864225
Vermersch P, Granziera C, Mao-Draayer Y, et al. Inhibition of CD40L with Frexalimab in Multiple Sclerosis. N Engl J Med. 2024;390(7):589-600. doi:10.1056/NEJMoa2309439