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Table 2 Optimal (under H0) two-stage parameters for testing H0: S(1) ≤ .35 vs H1: S(1) > .35. Power is 90% at S(1) = .5 *

From: Design of Phase II cancer trials evaluating survival probabilities

Minimized t 1 C 1 C 2 I 1/Imax EDA (%) MDA(%) ETSL (%) MTSL (%)
ETSL 1.8 .137 1.164 .31 2.65 (88) 3.71 (124) 3.10 (77) 4.71 (118)
  2.0 .270 1.164 .38 2.63 (88) 3.59 (120) 3.02 (76) 4.59 (115)
  2.2 @ .375 1.172 .46 2.65 (88) 3.44 (115) 3.00 (75) 4.44 (111)
  2.4 .464 1.184 .53 2.70 (90) 3.32 (111) 3.02 (75) 4.32 (108)
  2.6 .550 1.198 .61 2.78 (93) 3.22 (107) 3.07 (77) 4.22 (105)
EDA 1.5 -.313 1.223 .25 2.66 (89) 3.36 (112) 3.28 (82) 4.36 (109)
  1.7 -.125 1.218 .31 2.60 (87) 3.33 (111) 3.15 (79) 4.33 (108)
  1.9 @ .004 1.220 .38 2.58 (86) 3.27 (109) 3.08 (77) 4.27 (107)
  2.1 .109 1.227 .46 2.60 (87) 3.20 (107) 3.06 (76) 4.20 (105)
  2.3 .189 1.237 .53 2.65 (88) 3.13 (104) 3.08 (77) 4.13 (103)
  1. * t 1 is the time of the first interim review; C 1 and C 2 are the cutpoints for acceptance at the first stage and rejection at the second stage; EDA and MDA are the expected and maximum duration of accrual; and ETSL and MTSL are the expected and maximum total study length. Expected values are calculated under the null hypothesis; percentages are calculated relative to the single stage values. @ optimal design