Biostatistics
Clinical Data Management
Clinical Operations
Regulatory Affaris (including (pre-Clinical and Clinical)
Safety (Pharmacovigilance)
Medical writting (Scientific/protocol Dev.)
Compliance
All above have Project management position (PM). Pick either one you like, 40 Yrs old is not to late to start. Most important - excellent communication skill. What you wrote and said will be documented. PM is not for everyone. Need to be tough but reasonable.
Good luck