① Sanofi ① The experimental drug tolebrutinib failed to meet its primary endpoint in a late-stage clinical trial for the treatment of multiple sclerosis; ② The FDA's approval decision on tolebrutinib is expected to be further delayed, and Sanofi expects to receive further guidance from the FDA by the end of the first quarter of 2026.
Shares of French multinational pharmaceutical company Sanofi fell more than 4% in pre-market trading on Monday after its experimental drug for treating multiple sclerosis suffered a double blow: a late-stage clinical trial failed to meet key endpoints, while U.S. regulators hinted that the drug's approval decision would be delayed again.
Sanofi announced that its drug candidate, tolebrutinib, failed to meet its primary endpoint in a late-stage clinical trial for multiple sclerosis. Furthermore, the company stated that communications with the U.S. Food and Drug Administration (FDA) indicate that the regulatory review process for the drug in another multiple sclerosis indication will take longer than previously anticipated.
Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system, primarily affecting the brain, spinal cord, and optic nerve. Patients may experience symptoms such as decreased vision, numbness and weakness in the limbs, and difficulty walking. The condition often recurs or gradually worsens. Currently, there is no cure; treatment focuses on slowing disease progression, reducing the frequency of relapses, and improving quality of life.
This series of developments is a blow to one of Sanofi's closest-to-commercial-ready drugs. In recent years, several of Sanofi's clinical trial results have fallen short of expectations, and the company is struggling to recover from these research setbacks. To bolster its product pipeline, Sanofi has increased its acquisition and collaboration efforts this year, primarily funded by proceeds from the previous sale of a controlling stake in its consumer health business.
According to market consensus forecasts provided by Visible Alpha, analysts previously believed that tolebrutinib was likely to be approved and achieve sales of more than €1 billion (approximately US$1.17 billion) by 2030.
Sanofi stated that in a late-stage study for primary progressive multiple sclerosis (MPMS), tolebrutinib failed to meet the primary endpoint of slowing disability progression. Therefore, the company has decided to discontinue its regulatory application for this indication. This type of MPMS is characterized by slow, continuous deterioration of neurological function, with the condition worsening over time and no remission periods.
"We are disappointed with the results announced today; however, we believe that these data will help us to further understand the underlying biological mechanisms of multiple sclerosis," said Houman Ashrafian, head of research and development at Sanofi.
However, Sanofi remains confident in the therapeutic potential of tolebrutinib in another disease type—non-relapsing secondary progressive multiple sclerosis (NPMS). In this type, although patients no longer experience relapses, symptoms continue to accumulate and worsen.
Sanofi stated that the test results will prompt the company to assess whether it needs to recognize an impairment loss on the asset value of tolebrutinib. The company emphasized that this test will not affect net profit excluding one-off items, and its 2025 performance guidance remains unchanged.
Furthermore, Sanofi stated that the FDA's approval decision on tolebrutinib for non-relapsing secondary progressive multiple sclerosis is expected to be further delayed. Previously, the company disclosed in September that the review period for the drug had been extended by three months.
Sanofi stated that discussions with the FDA regarding the application indicate that the review process will extend beyond the target approval date of December 28th, and the company expects to receive further guidance from the FDA by the end of the first quarter of 2026.
At the same time, Sanofi also stated that, at the FDA's request, it has submitted an "expanded use protocol" to allow eligible patients who are not participating in clinical trials to access the therapy. Sanofi emphasized that it is confident in the drug's risk-benefit profile.
Jefferies analysts commented that the trial results were a negative surprise, but they pointed out that tolebrutinib's greatest commercial potential remains in the non-relapsing secondary progressive multiple sclerosis patient population.
(Article source: CLS)
