Fig. 2

Number of subjects included in sequential trials “standard” and “changing with time” specific cases, (p_C = 0.50). Red diamonds denoted median of subject included and lines denoted 5th and 95th percentiles. Dashed lines corresponded to NSN_F1 = 60 and NSN_F2 = 248. Abbreviations: p_C indicates control survival rate; ∆: simulated survival rate difference; F1: fixed single-arm design; S1: group-sequential single-arm design; F2: fixed two-arm design; S2: group-sequential two-arm design; “Standard”: specific case with a fixed control survival rate; “Changing with time”: specific case with an increase of the control survival rate over time