drugdevelopR (version 1.0.2)

Ess_tte: Expected sample size for phase III for multiarm programs with time-to-event outcomes

Description

Given phase II results are promising enough to get the "go"-decision to go to phase III this function now calculates the expected sample size for phase III given the cases and strategies listed below. The results of this function are necessary for calculating the utility of the program, which is then in a further step maximized by the optimal_multiarm() function

Usage

Ess_tte(HRgo, n2, alpha, beta, ec, hr1, hr2, strategy, case)

Value

the function Ess_tte() returns the expected sample size for phase III when going to phase III

Arguments

HRgo

threshold value for the go/no-go decision rule

n2

total sample size for phase II; must be even number

alpha

significance level

beta

1-beta power for calculation of sample size for phase III

ec

control arm event rate for phase II and III

hr1

assumed true treatment effect on HR scale for treatment 1

hr2

assumed true treatment effect on HR scale for treatment 2

strategy

choose Strategy: 1 ("only best promising"), 2 ("all promising") or 3 (both)

case

different cases: 1 ("nogo"), 21 (treatment 1 is promising, treatment 2 is not), 22 (treatment 2 is promising, treatment 1 is not), 31 (both treatments are promising, treatment 1 is better), 32 (both treatments are promising, treatment 2 is better)

Examples

res <- Ess_tte(HRgo = 0.8 ,n2 = 50 ,alpha = 0.05, beta = 0.1,
                            ec = 0.6, hr1 = 0.7, hr2 = 0.8, strategy = 2, case = 21)