Sanofi’s (NASDAQ:SNY) multiple sclerosis (MS) drug candidate tolebrutinib did not meet the primary endpoint of two studies testing the drug against relapsing MS.

The drug did not significantly reduce the annualized relapse rate over Sanofi’s Aubagio, a pyrimidine synthesis inhibitor indicated for treating relapsed MS, in the GEMINI 1 and 2 studies.

However, tolebrutinib did meet the primary endpoint in the HERCULES phase 3 study, which was to delay onset of confirmed disability progression in non-relapsing secondary progressive MS, for which there are currently no approved therapies.

The French drugmaker has been pushing for several opportunities in MS as its other popular MS drug Aubagio faces generic competition.

Sanofi (SNY) is still testing tolebrutinib in the PERSEUS phase 3 study for primary progressive MS, evaluating time to onset of confirmed disability progression. Study results are expected in 2025.