New MS Studies Find High-Efficacy Drugs Cut Relapses, Not Long-Term Disability

Since Novartis announced on September 3, 2026 that its oral MS drug remibrutinib beat Sanofi's teriflunomide in two Phase III trials, two separate pieces of independent research have landed that challenge how doctors and drugmakers talk about "slowing disability" in multiple sclerosis.

The first is a study out of the Karolinska Institute in Stockholm, published September 9, 2026 in Neurology Open Access and covered by both MedPage Today and Medical Xpress. Researchers led by Fredrik Piehl, MD, PhD, followed 509 newly diagnosed MS patients for two years as part of the MultipleMS cohort. Patients on B-cell-depleting drugs like rituximab and ocrelizumab, and other high-efficacy therapies, had far fewer relapses than patients on oral platform drugs like dimethyl fumarate and teriflunomide, with an incidence rate ratio of 0.38. They also had less MRI lesion growth.

But disability scores after two years looked basically the same across every treatment group. So did serum neurofilament light, a blood marker of nerve damage.

"Even so, B-cell-depleting therapies and other strong treatments were linked to fewer relapses and fewer MRI changes," Piehl said in a statement. "But after two years, we did not see clear differences in disability scores."

Piehl's team was careful to note the study can't prove cause and effect, since doctors were already steering certain patients toward certain drugs based on how their disease looked. That's a real limitation. But the pattern held across a large real-world sample, not a hand-picked trial population.

A nationwide Danish study, published in BMJ Neurology Open and reported by Multiple Sclerosis News Today on August 25, 2026, found something similar. Patients started early on high-efficacy therapies had a lower risk of relapse-related disability than patients who started on moderate drugs and escalated later. But their risk of progression independent of relapse activity, known as PIRA, was no different between the two groups.

The Danish researchers concluded that relapse-driven damage and PIRA-driven damage "represent partially independent mechanisms requiring potentially different therapeutic approaches." Translation: stopping relapses is not the same thing as stopping the disease.

Novartis's REMODEL-1 and REMODEL-2 trials, each enrolling roughly 1,000 relapsing MS patients, showed remibrutinib beat teriflunomide on annualized relapse rate and MRI lesions, according to pmlive. The company also said the drug showed "clinically meaningful" results on disability progression, with a positive trend on three-month confirmed disability progression and statistical significance on the six-month measure in a combined analysis, per pmlive's report.

Quartz reported that Novartis shares rose 4.5% on the announcement, pushing the stock's 2026 gain to 18%, and quoted UBS analyst Matt Weston calling remibrutinib "a no-brainer" given its clean liver-safety profile compared to rival BTK inhibitors. Sanofi's competing BTK drug, tolebrutinib, was rejected by the FDA in December after failing to beat Aubagio on relapses, Quartz noted.

That's a real result. Beating an established comparator on relapse rate and lesions, with no liver-toxicity signal across more than 4,500 trial participants, is significant. Novartis's chief medical officer, Shreeram Aradhye, said the results address "an unmet need" for oral drugs with a favorable safety profile, according to both pmlive and Quartz.

But the MultipleMS and Danish data suggest that a "positive trend" on disability progression, especially at the shorter three-month confirmation window that fell short of full statistical significance in the combined analysis, deserves scrutiny once the complete dataset comes out. Relapse suppression is well-established medicine. Whether it actually changes a patient's long-term trajectory is the harder, unresolved question, according to Carmen Tur, MD, PhD, of the Multiple Sclerosis Centre of Catalonia, who wrote in an accompanying editorial that the MultipleMS findings point to "a poor ability of high-efficacy therapies and B-cell-depleting therapies to reduce chronic inflammation despite their strong effect against acute inflammation."

Novartis has said it will present the complete REMODEL trial data, including full disability-progression figures, at a medical conference in Toronto. Reuters reported two patient deaths during the trials that investigators determined were unrelated to the study drug, and analysts told Reuters they want more detailed safety data before drawing conclusions.

Nobody in these studies claims high-efficacy or B-cell-depleting drugs are worthless. They cut relapses, and fewer relapses matters to patients living day to day. What none of this research shows is that these drugs stop the slow, relapse-independent decline that both the Swedish and Danish teams say may account for a large share of long-term MS disability. Until a drug demonstrates that separately, "beats the competitor on relapses" and "stops the disease" remain two different claims.