The late-stage study results, presented at the MSToronto2026 congress and published in The Lancet, showed remibrutinib reduced annualized relapse rates by 35.2% and 31.2% against Sanofi’s Aubagio. These figures fell short of the 51.1% and 58.5% reductions reported by Roche for its own candidate, fenebrutinib. Investors had pinned their hopes on Novartis delivering a drug that could mirror Roche’s potency while maintaining a cleaner safety profile.

Novartis Chief Medical Officer Shreeram Aradhye emphasized that the drug showed no signs of liver toxicity, a notable contrast to the potential injury risks identified in Roche’s trials. Despite this safety advantage, the clinical efficacy remains the primary hurdle for the Swiss firm. Coming off recent trial setbacks in cholesterol and neuromuscular treatments, the company needed a clear win to restore market confidence. Analysts at UBS had previously signaled that anything less than parity with the Roche data would dampen investor enthusiasm, a prediction borne out by the immediate volatility in the company’s American depositary receipts.