EPsProg_multitrial_normal: Expected probability of a successful program for multitrial...

In Sterniii3/drugdevelopR: Utility-Based Optimal Phase II/III Drug Development Planning

Expected probability of a successful program for multitrial programs with normally distributed outcomes

Description

These functions calculate the expected probability of a successful program given the parameters. Each function represents a specific strategy, e.g. the function EpsProg3_normal() calculates the expected probability if three phase III trials are performed. The parameter case specifies how many of the trials have to be successful, i.e. how many trials show a significantly relevant positive treatment effect.

Usage

EPsProg2_normal(
  kappa,
  n2,
  alpha,
  beta,
  w,
  Delta1,
  Delta2,
  in1,
  in2,
  a,
  b,
  case,
  size,
  fixed
)

EPsProg3_normal(
  kappa,
  n2,
  alpha,
  beta,
  w,
  Delta1,
  Delta2,
  in1,
  in2,
  a,
  b,
  case,
  size,
  fixed
)

EPsProg4_normal(
  kappa,
  n2,
  alpha,
  beta,
  w,
  Delta1,
  Delta2,
  in1,
  in2,
  a,
  b,
  case,
  size,
  fixed
)

Arguments

kappa	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
w	weight for mixture prior distribution
Delta1	assumed true treatment effect for standardized difference in means
Delta2	assumed true treatment effect for standardized difference in means
in1	amount of information for Delta1 in terms of sample size
in2	amount of information for Delta2 in terms of sample size
a	lower boundary for the truncation
b	upper boundary for the truncation
case	choose case: "at least 1, 2 or 3 significant trials needed for approval"
size	size category "small", "medium" or "large"
fixed	choose if true treatment effects are fixed or random

Details

The following cases can be investigated by the software:

• Two phase III trials

  • Case 1: Strategy 1/2; at least one trial significant, the treatment effect of the other one at least showing in the same direction

  • Case 2: Strategy 2/2; both trials significant

• Three phase III trials

  • Case 2: Strategy 2/3; at least two trials significant, the treatment effect of the other one at least showing in the same direction

  • Case 3: Strategy 3/3; all trials significant

• Four phase III trials

  • Case 3: Strategy 3/4; at least three trials significant, the treatment effect of the other one at least showing in the same direction

Value

The output of the function EPsProg2_normal(), EPsProg3_normal() and EPsProg4_normal() is the expected probability of a successful program when performing several phase III trials (2, 3 or 4 respectively).

Examples

EPsProg2_normal(kappa = 0.1, n2 = 50, alpha = 0.025, beta = 0.1, w = 0.3,
                                 Delta1 = 0.375, Delta2 = 0.625, in1 = 300, in2 = 600, 
                                 a = 0.25, b = 0.75, 
                                 case = 2, size = "small", fixed = FALSE)
          EPsProg3_normal(kappa = 0.1, n2 = 50, alpha = 0.025, beta = 0.1, w = 0.3,
                                 Delta1 = 0.375, Delta2 = 0.625, in1 = 300, in2 = 600, 
                                 a = 0.25, b = 0.75, 
                                 case = 2, size = "small", fixed = TRUE)
          EPsProg4_normal(kappa = 0.1, n2 = 50, alpha = 0.025, beta = 0.1, w = 0.3,
                                 Delta1 = 0.375, Delta2 = 0.625, in1 = 300, in2 = 600, 
                                 a = 0.25, b = 0.75, 
                                 case = 3, size = "small", fixed = TRUE)                      

Sterniii3/drugdevelopR documentation built on Jan. 26, 2024, 6:17 a.m.