High-efficacy therapy 'superior' in reducing relapses, but not delaying disability, in MS

Patients with active secondary progressive MS who received high-efficacy therapy experienced relapses less often than those on low-efficacy therapy, according to findings published in Neurology.

However, the results also demonstrated no difference regarding the speed at which the disease progressed between high-efficacy and low-efficacy therapy, according to a press release.

“[MS] is a complicated disease to treat and must be closely monitored as it is managed with various medications, some of which can have serious side effects,” study author Tomas Kalincik, MD, PhD, a professorial fellow of neurological outcomes at the University of Melbourne in Australia, said in the press release. “High-efficacy medications are prescribed in early [MS] to more aggressively treat the disease and have been found to more effectively prevent flare-ups and modify progression, but less is known about how effective these therapies may be later when relapsing-remitting MS transitions to secondary progressive MS.”

Kalincik, along with Izanne Roos, MBChB, MMed, a consultant neurologist at the Royal Melbourne Hospital in Australia, and colleagues aimed to examine the differences in clinical efficacy for high-efficacy vs. low-efficacy treatments in patients with recently active and inactive SPMS “after accounting for therapeutic lag,” according to the study results. They pulled data from two large, longitudinal, observational clinical datasets and retrospectively identified patients with SPMS.

The researchers selected patients with SPMS who received high-efficacy therapy, including natalizumab, alemtuzumab, mitoxantrone, ocrelizumab, rituximab, cladribine, fingolimod, or low-efficacy therapy, including interferon beta, glatiramer acetate or teriflunomide. They calculated the therapeutic lag for each patient according to their demographic and clinical characteristics and used propensity scores to match patients treated with low vs. high efficacy therapy. Kalincik and colleagues then compared outcomes, after disregarding the period of therapeutic lag, in paired, pairwise-censored analyses.

The study included 1,000 patients (510 with active SPMS and 490 with inactive SPMS) in the primary analysis. The researchers found that patients who received high-efficacy therapy had relapses less often than those who received low-efficacy therapy (HR = 0.7; P = .006). They noted no evidence for a difference in relapse rates between groups among the patients with inactive SPMS and no evidence for a difference in the risk for disability progression, according to the study results.

The researchers acknowledged that grouping patients according to therapeutic efficacy was a limitation of the study but noted that the therapies “were not studied individually,” according to the press release. Kalincik suggested that future studies look at the treatments separately, as they could have different effects on symptoms and disability.

“Our study finding that high-efficacy therapies are superior to low-efficacy therapies only in reducing relapses in people with active [SPMS] provides valuable guidance for neurologists when choosing the most effective therapies for people with this form of MS,” Kalincik said. “When the goal is to alleviate ongoing relapse activity, more potent therapy is justified. But when the goal is to limit disability progression in secondary progressive MS, both types of drugs show comparable effectiveness.”

Reference:

American Academy of Neurology. Are multiple sclerosis drugs used early on in the disease also effective later? Available at: https://www.aan.com/PressRoom/Home/PressRelease/4905. Accessed July 6, 2021.