Your an exempt employee, which means Sanofi can be as unreasonable as they like because you are not protected by the Fair Labor Standards Act. If they want you making sales calls 30 hours a day, 10 days a week they can ask you to do so, and if you don't like it you can leave.
Good companies don't behave like that, which is why they have loyal employees, but no court can protect you from an abusive work environment under a law that does not apply to you. Pray to get downsized or, better yet, send out some resumes and see if you can do better. Sanofi is not the only game in town.