Novartis Backs Remibrutinib at $4 Billion as Kisqali, Kesimpta Patents Near 2032

Novartis CEO Vas Narasimhan said on Tuesday that remibrutinib, the company's experimental multiple sclerosis medicine, could reach more than $4 billion in peak annual sales. "This medicine could be one of our largest medicines in history," Narasimhan told CNBC. The company guides to $8 billion-plus in total sales for remibrutinib, counting indications beyond relapsing MS. Novartis estimates a $6 billion-plus peak annual sales opportunity for Kesimpta alongside that $4 billion-plus figure for remibrutinib in relapsing MS.

The forecast arrived days after Barclays cut its own peak sales projection for the drug. Detailed results from two late-stage trials showed remibrutinib reduced relapses in MS patients by less than analysts had expected. Amit Bar-Or, a multiple sclerosis specialist at the University of Pennsylvania, said remibrutinib appeared to offer a promising safety profile but was unlikely to control relapsing MS as effectively as high-efficacy antibodies like Novartis' own Kesimpta. He added that the drug's biggest opportunity to expand the market could emerge if ongoing trials demonstrate a benefit in progressive multiple sclerosis, where treatment options remain limited.

Novartis reported sales growth this week after losing key patent protection for its heart drug Entresto. Barclays analysts said on Wednesday that the market is already looking to the next patent cliff, with Kisqali and Kesimpta facing expirations around 2032. Those two drugs represent $18 billion in peak sales combined, the analysts said. Remibrutinib belongs to a class of medicines called BTK inhibitors, which aim to reduce the immune system activity that damages nerves in MS patients. Kesimpta is a monoclonal antibody that binds the CD20 protein, depleting B cells involved in the autoimmune response. Unlike Kesimpta, remibrutinib aims to regulate the cells' activity without eliminating them.

Bar-Or said clinical results for remibrutinib in relapsing MS appear similar to Roche's rival BTK inhibitor fenebrutinib, but less effective at preventing relapses than anti-CD20 treatments such as Kesimpta. No head-to-head trials have compared remibrutinib with fenebrutinib or anti-CD20 treatments, making direct comparisons difficult. He said the drug could still be an attractive switch for patients experiencing progressive MS while on an anti-CD20. A trial testing remibrutinib in progressive MS is expected to read out in 2031. Bar-Or said BTK inhibitors may have a long-term safety advantage because they regulate immune cells rather than eliminate them, but added there is not yet enough long-term safety data to confirm this.

A Novartis spokesperson said the company views remibrutinib primarily as an opportunity to expand its MS portfolio, not to replace Kesimpta sales. The company is targeting newly diagnosed patients, people taking oral treatments, and patients on anti-CD20 therapies who may be eligible to switch. Morningstar analyst Jay Lee called the $4 billion-plus peak sales forecast "within the realm of possibility" but said it was not "de-risked." Lee said the outcome depends on how remibrutinib compares with fenebrutinib, drug pricing negotiations, and whether tolerability advantages translate into patients staying on treatment longer.

In the near term, Lee said he expects the largest market for remibrutinib will be the oral switch market, meaning patients taking a generic oral treatment who need to switch, particularly for tolerability reasons. Investors are now focused on the RESHAPE trial, which enrolled patients aged 40 to 70 taking Roche's anti-CD20 antibody Ocrevus; results are expected in 2028. Lee said any share taken from CD20 drugs "may still work in Novartis' favor if it means they gain overall RMS patient share from Roche, which currently leads the market." Novartis estimates about 75% of switch-eligible patients on CD20 drugs are not on Kesimpta.

Novartis is set to outline its long-term growth strategy in mid-November. Remibrutinib is already approved for certain forms of chronic hives, and a late-stage trial in hidradenitis suppurativa is expected to read out before Nov. 19. Barclays estimates a $2 billion peak annual sales opportunity in that condition but assigns the drug a 50% probability of success, citing an unusual dose-response pattern in mid-stage trials and a history of late-stage trial failures in hidradenitis suppurativa. A trial testing remibrutinib in progressive MS is expected to read out in 2031.

Kisqali and Kesimpta face patent expirations around 2032. Barclays put their combined peak sales at $18 billion.