Novartis MS Pill: How does Rhapsido avoid liver toxicity?

The Novartis MS Pill, Rhapsido (remibrutinib), has cleared a major Phase 3 hurdle in relapsing multiple sclerosis (RMS). But the headline comes with an important clinical caveat.

The Novartis MS pill significantly reduced annualized relapse rates (ARR) and MRI brain lesions compared with Sanofi’s Aubagio (teriflunomide).

Yet the early disability-progression data were more nuanced. The results came from the REMODEL-1 and REMODEL-2 Phase 3 trials, which enrolled about 2,000 people with RMS.

Novartis said the trials met their primary endpoint and showed superiority on key secondary measures, including MRI lesion reduction.

What did the MS trials actually show?

The biggest efficacy signal was the reduction in ARR versus teriflunomide. However, disability progression needs a closer look.

In the preplanned pooled analysis of REMODEL-1 and REMODEL-2, remibrutinib showed a positive trend in 3-month confirmed disability progression (3mCDP). Novartis did not report statistical significance for this endpoint in its topline release. The drug achieved nominal statistical significance for 6-month confirmed disability progression (6mCDP).

That distinction matters. Relapse reduction and MRI outcomes are strong indicators of disease activity, but sustained disability progression is a critical measure of how MS affects patients over time. Full numerical results are still awaited.

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Why is Rhapsido’s liver safety important?

The Novartis MS Pill enters a BTK inhibitor market where liver toxicity has become a major concern.

Remibrutinib recorded zero cases meeting Hy’s Law criteria across its clinical development program, according to Novartis. That stands in sharp contrast to Sanofi’s tolebrutinib. The FDA identified six Hy’s Law cases among about 2,700 participants, including one patient who required a liver transplant and later died. The FDA cited severe drug-induced liver injury as a key reason for rejecting the drug.

The REMODEL trials also reported two deaths, but Novartis said neither was considered treatment-related. Meanwhile, Roche’s FENhance 1 and 2 trials of fenebrutinib reported eight fatal cases in the fenebrutinib arms, although the causes varied and further analysis was ongoing.

How does remibrutinib work differently?

The Novartis MS Pill is a highly selective, covalent oral Bruton's tyrosine kinase (BTK) inhibitor. It blocks BTK signaling involved in B-cell and innate immune-cell activation. This helps regulate inflammatory pathways linked to MS without broadly suppressing the adaptive immune system.

Rhapsido is already an approved medicine. The FDA approved it in September 2025 for chronic spontaneous urticaria, or persistent hives. Novartis reported USD 64 million in Q2 2026 sales. Analysts see a much larger opportunity, with estimates ranging from more than USD 3 billion in peak MS sales to high-single-digit billions across potential indications such as food allergy and hidradenitis suppurativa.

The drug could also strengthen Novartis’ MS portfolio alongside Kesimpta and compete for patients using high-efficacy therapies such as Roche’s Ocrevus.

The next major test comes in October 2026, when Novartis plans to present the detailed REMODEL-1 and REMODEL-2 results as a late-breaking presentation at MSToronto2026. Global regulatory submissions are planned after the full data disclosure.