Sanofi reports positive results on MS drug licensed from Principia

The French drug giant Sanofi on Thursday reported positive results in a study of its new pill to treat multiple sclerosis.
The drug, which Sanofi licensed from South San Francisco-based Principia Biopharma in 2017, “significantly reduced disease activity associated with multiple sclerosis as measured by magnetic resonance imaging,” the company said in a statement. Full data on the drug, called SAR442168, are not being made available yet, but will be presented at a later medical meeting.
The drug is designed to be different than existing treatments for the disease because it can enter the brain. In multiple sclerosis, the immune system attacks nerve cells in the brain and spinal cord; current treatments may have trouble protecting brain cells.

Sanofi controls all development of the drug, but the medicine has become important to its stock price, as well as Principia’s. It is seen as a key asset in the effort of new CEO Paul Hudson and research chief John Reed to revitalize Sanofi, and as a potential source of revenue for Principia, which has seen its stock price double in the past 12 months.

The design of the latest study was complicated and somewhat unorthodox. The goal of the new design was to spare patients having to take a placebo, said Erik Wallstroem, therapy head for neurology at Sanofi, and to speed up the conduct of the trial. Even larger studies in MS, he said, rely largely on MRI data, and Sanofi wanted to get evidence as quickly as possible.
Instead of comparing every dose of the drug to a placebo group, 60 patients received one of four doses of SAR442168 for 12 weeks, followed by four weeks on placebo. Another 60 received four weeks of placebo, followed by 12 weeks of SAR442168. The main statistical analysis of the study will compare the patients who received placebo first at four weeks to all of the patients after 12 weeks of taking the drug. (Patients who got placebo for the first four weeks would be measured at week 16; those who started on SAR442168 were measured at week 12.)
The result was that new active brain lesions seen on MRI were reduced in patients who had taken SAR442168 for 12 weeks compared to those who received placebo for four weeks. The statistical analysis takes into account whether this efficacy changed based on dose, a sign that a drug is effective.
“I would argue that that it gives quite a lot of confidence because you get a good read on the MRI,” said Wallstroem, “and we know that the MRI is strongly linked to the phase three outcomes.” He also emphasized that the study succeeded in being fast: It was started in 2019, and results are already available.
SAR44216 works by inhibiting Bruton’s tyrosine kinase, or BTK, a target on b-cells. Another BTK inhibitor, Imbruvica, is used to treat some blood cancers. No BTK inhibitor is yet approved in MS.

Sanofi reports positive results on multiple sclerosis drug licensed from Principia