Hi David,
Basically agree with Darwin. There is no one size that fits all. In my opinion, the frequency or time points for TMF review should be flexible and adapted to the study. Usually, Phase 1 studies are of short duration and so I would recommend to perform a review at time of site close-out and then one at the end of the study. Again, frequency and/or time points/milestones should be determined by the study team at the beginning of the study and agreement recorded in the TMF management plan.