Novartis Faces $18 Billion Patent Cliff While Pushing New MS Drug

Novartis executives are projecting that its new multiple sclerosis drug, remibrutinib, could eventually generate over $4 billion in annual sales, but Wall Street analysts are focused on a larger financial threat looming in 2032.

The timeline for this challenge began when Novartis reported sales growth this week despite losing patent protection for its heart drug, Entresto. Days later, Barclays lowered its forecast for remibrutinib after late-stage trial results showed the drug reduced relapses in MS patients by less than expected. The bank stated that investors are now looking past Entresto to the next patent cliff.

According to Barclays, the expirations of bestsellers Kisqali and Kesimpta around 2032 represent $18 billion in peak sales. The analysts called this the market's bigger question for the company. Novartis is preparing to outline its long-term growth strategy in mid-November against this backdrop.

Remibrutinib is a BTK inhibitor that aims to reduce immune system activity that damages nerves in MS patients. It works differently from Novartis' existing drug Kesimpta, which is a monoclonal antibody that depletes B cells. Remibrutinib regulates these cells without eliminating them. Novartis has guided for over $8 billion in total sales for remibrutinib, including indications other than relapsing MS.

Amit Bar-Or, a multiple sclerosis specialist at the University of Pennsylvania, noted that remibrutinib likely will not control relapsing MS as effectively as high-efficacy antibodies like Kesimpta. He described the drug as a promising option for patients with progressive MS, where treatment options are limited. Bar-Or said the drug's biology distinguishes relapsing MS, characterized by flare-ups, from progressive MS, which worsens gradually.

Clinical results for remibrutinib appear similar to Roche's rival BTK inhibitor fenebrutinib, though less effective at preventing relapses than anti-CD20 treatments. No head-to-head trials have yet compared these drugs directly. Bar-Or suggested that remibrutinib could be an attractive switch for patients experiencing progressive MS while on an anti-CD20 drug. An ongoing trial testing this specific benefit is expected to report results in 2031.

Novartis views remibrutinib as a way to expand its MS portfolio rather than replace Kesimpta. The company targets newly diagnosed patients, those on oral treatments, and those eligible to switch from anti-CD20 therapies. Novartis sees a peak annual sales opportunity of over $6 billion for Kesimpta alongside the $4 billion projection for remibrutinib in relapsing MS.

Morningstar analyst Jay Lee called the $4 billion forecast for remibrutinib possible but not de-risked. He said the outcome depends on comparisons with fenebrutinib, pricing negotiations, and patient retention. Lee expected the largest near-term market to be patients switching from generic oral treatments due to tolerability issues. He noted that investors are watching the RESHAPE trial, which enrolled patients on Roche's Ocrevus and is expected to report in 2028.

Lee added that gaining overall relapsing MS patient share from Roche would work in Novartis' favor. Novartis estimates that about 75% of switch-eligible patients on CD20 drugs are not on Kesimpta. Remibrutinib is already approved for certain forms of chronic hives. A late-stage trial for the skin disease hidradenitis suppurativa is expected to report before Nov. 19. Barclays estimates a $2 billion peak sales opportunity in that area but assigns a 50% probability of success due to historical trial failures.