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. Author manuscript; available in PMC: 2019 Aug 23.
Published in final edited form as: Biometrics. 2019 Apr 3;75(2):371–381. doi: 10.1111/biom.12994

Table 6.

Robustness simulation results. α = probability of a type I error or concluding that an inferior version of A is better than C under the null. γ1 = generalized power at xSopt under the alternative hypothesis (probability of selecting the best dose xSopt and declaring A(xSopt) superior to C). γ2 = generalized power (probability of selecting any superior dose and declaring A(x^Sopt) superior to C). W¯ is the mean improvement in survival time under the alternative hypothesis. Dur¯ and N¯ are the mean trial duration and sample size, respectively.

Scenario Distribution Phase I-II phase III
Phase I-II/III Design
W¯
γ1 γ2 α
W¯
γ1 γ2 α
1 Lognormal, σ = .5 7.72 .30 .30 .02 14.56 .80 .80 .03
Lognormal, σ = 1 6.18 .30 .30 .02 14.88 .85 .85 .03
Weibull Increasing 6.37 .30 .30 .02 12.00 .77 .77 .03
Weibull Decreasing 1.96 .13 .13 .02 4.14 .32 .32 .02
Gamma 5.02 .30 .30 .02 11.72 .89 .89 .04
2 Lognormal, σ = .5 12.18 .73 .73 .05 15.14 .91 .91 .05
Lognormal, σ = 1 11.70 .70 .70 .06 13.78 .82 .82 .03
Weibull Increasing 9.08 .73 .73 .06 11.20 .90 .90 .06
Weibull Decreasing 3.98 .32 .32 .05 4.75 .38 .38 .03
Gamma 9.11 .73 .73 .06 11.30 .90 .90 .03
3 Lognormal, σ = .5 2.17 .06 .06 < .01 13.91 .85 .85 .04
Lognormal, σ = 1 2.02 .06 .06 < .01 12.91 .81 .81 .03
Weibull Increasing 2.14 .06 .06 < .01 13.63 .84 .84 .03
Weibull Decreasing .90 .03 .03 < .01 4.94 .32 .32 .03
Gamma 2.07 .06 .06 < .01 13.23 .86 .86 .03
4 Lognormal, σ = .5 4.50 .32 .32 .05 7.23 .52 .52 .05
Lognormal, σ = 1 3.86 .28 .28 .05 5.61 .40 .40 .06
Weibull Increasing 4.67 .33 .33 .04 6.61 .47 .47 .04
Weibull Decreasing 4.14 .28 .28 .06 6.21 .42 .42 .07
Gamma 4.62 .31 .31 .04 6.93 .47 .47 .04
5 Lognormal, σ = .5 6.63 .21 .25 .01 18.19 .76 .96 .03
Lognormal, σ = 1 5.74 .21 .25 .01 16.78 .69 .87 .03
Weibull Increasing 7.41 .21 .25 .01 15.88 .64 .77 .03
Weibull Decreasing 4.00 .16 .18 .01 12.27 .48 .63 .03
Gamma 6.73 .21 .25 .01 18.73 .80 .92 .03
6 Lognormal, σ = .5 11.92 .34 .52 .04 15.56 .58 .83 .06
Lognormal, σ = 1 11.50 .34 .52 .02 15.66 .60 .80 .04
Weibull Increasing 10.29 .34 .52 .04 12.76 .54 .77 .05
Weibull Decreasing 5.46 .21 .31 .02 6.63 .32 .38 .03
Gamma 10.90 .34 .52 .02 14.80 .59 .83 .04