Sanofi faces delays in US regulatory decision for multiple sclerosis drug and reports disappointing trial results. Analysts concerned about impact on future drug portfolio. FDA decision on tolebrutinib delayed for second time. Drug fails to slow disability progression in late-stage trial, raising doubts about projected peak sales. Despite challenges, drug received breakthrough therapy designation.

Read more at Yahoo Finance: Delayed MS Decision and Trial Miss Add to Sanofi’s R&D Challenges