[Phases 0, 1 and 2 oncology clinical trials: current questions].

We propose here a general review of current questions related to early trials, including the choice of the primary endpoint, role of bayesian designs, role of stratification and randomization for phase 2 trials, patient selection, and new designs for phase 1 and phase 0 trials. We also discuss the difficulties to apply such methodologies to molecular targeted therapies development.