Package 'gen2stage'

Title: Generalized Two-Stage Designs for Phase II Single-Arm Studies
Description: One can find single-stage and two-stage designs for a phase II single-arm study with either efficacy or safety/toxicity endpoints as described in Kim and Wong (2019) <doi:10.29220/CSAM.2019.26.2.163>.
Authors: Seongho Kim
Maintainer: Seongho Kim <[email protected]>
License: GPL (>= 2)
Version: 1.0
Built: 2024-12-01 08:00:06 UTC
Source: CRAN

Help Index


Generalized Two-Stage Designs for Phase II Single-Arm Studies

Description

The R package gen2stage can generate single-stage and two-stage designs for phase II single-arm efficacy or safety studies.

Details

Package: gen2stage
Type: Package
Version: 1.0
Date: 2017-10-05
License: GPL-2

Author(s)

Seongho Kim <[email protected]>

References

Kim S and Wong WK. Phase II Two-Stage Single-Arm Clinical Trials for Testing Toxicity Levels. Commun Stat Appl Methods. 2019 Mar;26(2):163-173. https://www.ncbi.nlm.nih.gov/pubmed/31106162.

Examples

# Single-stage safety design with pu (p0) = 0.33 vs. pa (p1) = 0.20
  gen2single(0.33, 0.20, 0.05, 0.20)

  # Single-stage efficacy design with pu (p0) = 0.67 vs. pa (p1) = 0.80
  gen2single(0.67, 0.80, 0.05, 0.20)

  # save and print
  safety1 = gen2single(0.33, 0.20, 0.05, 0.20)
  print(safety1)

  # Two-stage safety design with pu (p0) = 0.33 vs. pa (p1) = 0.20
  gen2simon(0.33, 0.20, 0.05, 0.20)
  gen2simon(0.33, 0.20, 0.05, 0.10, nmax=150)

  # Two-stage efficacy design with pu (p0) = 0.67 vs. pa (p1) = 0.80
  gen2simon(0.67, 0.80, 0.05, 0.20)
  gen2simon(0.67, 0.80, 0.05, 0.10, nmax=150)

  # save, print and plot
  safety2 = gen2simon(0.33, 0.20, 0.05, 0.20)
  print(safety2)
  plot(safety2)

Generalized Simon's 2-stage phase II design

Description

Calculates generalized optimal and minimax 2-stage phase II designs based on the R function ph2simon.

Usage

gen2simon(pu, pa, ep1, ep2, nmax=100)
## S3 method for class 'gen2simon'
print(x, ...)
## S3 method for class 'gen2simon'
plot(x, ...)

Arguments

pu

unacceptable response/toxicity rate

pa

response/toxicity rate that is desirable

ep1

threshold for the probability of declaring drug/treatment desirable under p0

ep2

threshold for the probability of rejecting the drug/treatment under p1

nmax

maximum total sample size (default 100; can be at most 500)

x

object returned by gen2simon

...

arguments to be passed onto plot and print commands called within

Value

gen2simon returns a list with pu, pa, alpha, beta and nmax as above and:

out

matrix of best 2 stage designs for each value of total sample size n. The 6 columns are: r1, n1, r, n, EN(p0), PET(p0), alpha, beta

The "print" method formats and returns the minimax and optimal designs. The "plot" plots the expected sample size agains the maximum sample size as in Jung et al., 2001

References

Kim S and Wong WK. Phase II Two-Stage Single-Arm Clinical Trials for Testing Toxicity Levels. Commun Stat Appl Methods. 2019 Mar;26(2):163-173. https://www.ncbi.nlm.nih.gov/pubmed/31106162.

Jung SH, Carey M and Kim KM. (2001). Graphical Search for Two-Stage Designs for Phase II Clinical Trials. Controlled Clinical Trials 22, 367-372.

Simon R. (1989). Optimal Two-Stage Designs for Phase II Clinical Trials. Controlled Clinical Trials 10, 1-10.

See Also

oc.gentwostage.bdry

Examples

# Two-stage safety design with pu (p0) = 0.33 vs. pa (p1) = 0.20
  gen2simon(0.33, 0.20, 0.05, 0.20)
  gen2simon(0.33, 0.20, 0.05, 0.10, nmax=150)

  # Two-stage efficacy design with pu (p0) = 0.67 vs. pa (p1) = 0.80
  gen2simon(0.67, 0.80, 0.05, 0.20)
  gen2simon(0.67, 0.80, 0.05, 0.10, nmax=150)

  # save, print and plot
  safety2 = gen2simon(0.33, 0.20, 0.05, 0.20)
  print(safety2)
  plot(safety2)

Generalized exact single stage phase II design

Description

Calculates the generalized exact one stage phase II design based on the R function ph2single.

Usage

gen2single(pu,pa,ep1,ep2,nsoln=5)
## S3 method for class 'gen2single'
print(x, ...)

Arguments

pu

unacceptable response/toxicity rate

pa

response/toxicity rate that is desirable

ep1

threshold for the probability of declaring drug/treatment desirable under p0

ep2

threshold for the probability of rejecting the drug/treatment under p1

nsoln

number of designs with given alpha and beta

x

object returned by gen2single

...

arguments to be passed onto print command called within

Value

gen2single returns the optimal design with pu, pa, alpha, and beta as above and:

out

matrix of the single-stage designs up to nsoln. The 4 columns are: r, n, alpha (type I error), beta (type II erro)

The "print" method formats and returns the optimal design.

References

Kim S and Wong WK. Phase II Two-Stage Single-Arm Clinical Trials for Testing Toxicity Levels. Commun Stat Appl Methods. 2019 Mar;26(2):163-173. https://www.ncbi.nlm.nih.gov/pubmed/31106162.

See Also

gen2simon

Examples

# Single-stage safety design with pu (p0) = 0.33 vs. pa (p1) = 0.20
  gen2single(0.33, 0.20, 0.05, 0.20)

  # Single-stage efficacy design with pu (p0) = 0.67 vs. pa (p1) = 0.80
  gen2single(0.67, 0.80, 0.05, 0.20)

  # save and print
  safety1 = gen2single(0.33, 0.20, 0.05, 0.20)
  print(safety1)

Two-stage boundary operating characteristics

Description

Calculates the operating characteristics of a two-stage boundary based on the R function oc.twostage.bdry.

Usage

oc.gentwostage.bdry(pu, pa, r1, n1, r, n)

Arguments

pu

unacceptable response rate

pa

response rate that is desirable

r1

first stage threshold to declare treatment undesirable

n1

first stage sample size

r

overall threshold to declare treatment undesirable

n

total sample size

Value

oc.gentwostage.bdry returns the type I and II error rates as well as the probability of early temination and expected sample size under pu for a specific boundary.

References

Kim S and Wong WK. Phase II Two-Stage Single-Arm Clinical Trials for Testing Toxicity Levels. Commun Stat Appl Methods. 2019 Mar;26(2):163-173. https://www.ncbi.nlm.nih.gov/pubmed/31106162.

See Also

gen2simon

Examples

# Optimal two-stage safety design with pu (p0) = 0.33 vs. pa (p1) = 0.20
  oc.gentwostage.bdry(0.33, 0.20, 8, 26, 22, 85)

  # Optimal two-stage efficacy design with pu (p0) = 0.67 vs. pa (p1) = 0.80
  oc.gentwostage.bdry(0.67, 0.80, 18, 26, 63, 85)