which efficacy population you are using for onc phase1/2a

For an oncology phase 1/2a study, including dose escalation and expansion periods, though efficacy is not the major objective, but still important. Using different efficacy population, actually will give different results for ORR, DCR, etc. I saw different cases, for instance: ITT(or mITT: all dosed pts having baseline measurement), OR adding other conditions on mITT, like also require: at least 1 post baseline efficacy measurement? I wonder which one should normally be used.