Package 'bfboinet'

Title: Backfill Bayesian Optimal Interval Design Using Efficacy and Toxicity
Description: The backfill Bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization (BF-BOIN-ET) design is a novel clinical trial design to allow patients to be backfilled at lower doses during a dose-finding trial while prioritizing the dose-escalation cohort to explore a higher dose. The advantages compared to the other designs in terms of the percentage of correct optimal dose (OD) selection, reducing the sample size, and shortening the duration of the trial, in various realistic setting.
Authors: Jing Zhu [cre, aut], Kentaro Takeda [aut]
Maintainer: Jing Zhu <[email protected]>
License: GPL-3
Version: 0.2.0
Built: 2025-03-12 05:47:12 UTC
Source: https://github.com/cran/bfboinet

Help Index


backboinet

Description

Obtain the operating characteristics of the backfill bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization within fixed scenarios

Usage

get.oc.backboinet(
  target_T = 0.3,
  toxprob,
  target_E = 0.25,
  effprob,
  n.dose,
  startdose,
  ncohort,
  cohortsize,
  pT.saf = 0.6 * target_T,
  pT.tox = 1.4 * target_T,
  pE.saf = 0.6 * target_E,
  alpha.T1 = 0.5,
  alpha.E1 = 0.5,
  tau.T,
  tau.E,
  te.corr = 0.2,
  gen.event.time = "weibull",
  accrual,
  gen.enroll.time = "uniform",
  n.earlystop = 6,
  stopping.npts = 12,
  suspend = 0,
  stopping.prob.T = 0.95,
  stopping.prob.E = 0.9,
  ppsi01 = 0,
  ppsi00 = 40,
  ppsi11 = 60,
  ppsi10 = 100,
  n.sim = 1000,
  seed.sim = 100
)

Arguments

target_T

Target toxicity probability. The default value is target_T=0.3. When observing 1 DLT out of 3 patients and the target DLT rate is between 0.25 and 0.279, the decision is to stay at the current dose due to a widely accepted practice.

toxprob

Vector of true toxicity probability.

target_E

The minimum required efficacy probability. The default value is target_E=0.25.

effprob

Vector of true efficacy probability.

n.dose

Number of dose.

startdose

Starting dose. The lowest dose is generally recommended.

ncohort

Number of cohort.

cohortsize

Cohort size.

pT.saf

Highest toxicity probability that is deemed sub-therapeutic such that dose-escalation should be pursued. The default value is pT.saf=target_T*0.6.

pT.tox

Lowest toxicity probability that is deemed overly toxic such that dose de-escalation is needed. The default value is pT.tox=target_T*1.4.

pE.saf

Minimum probability deemed efficacious such that the dose levels with less than delta1 are considered sub-therapeutic. The default value is pE.saf=target_E*0.6.

alpha.T1

Probability that toxicity event occurs in the late half of toxicity assessment window. The default value is alpha.T1=0.5.

alpha.E1

Probability that efficacy event occurs in the late half of assessment window. The default value is alpha.E1=0.5.

tau.T

Toxicity assessment windows (months).

tau.E

Efficacy assessment windows (months).

te.corr

Correlation between toxicity and efficacy probability, specified as Gaussian copula parameter. The default value is te.corr=0.2.

gen.event.time

Method to generate the time to first toxicity and efficacy outcome. Weibull distribution is used when gen.event.time ="weibull". Uniform distribution is used when gen.event.time="uniform". The default value is gen.event.time="weibull".

accrual

Accrual rate (months) (patient accrual rate per month).

gen.enroll.time

Method to generate enrollment time. Uniform distribution is used when gen.enroll.time="uniform". Exponential distribution is used when gen.enroll.time="exponential". The default value is gen.enroll.time="uniform".

n.earlystop

the early stopping parameter. If the number of patients treated at the current dose reaches n.earlystop,stop the trial and select the optimal dose (OD) based on the observed data.The default value is n.earlystop=6.

stopping.npts

Early study termination criteria for the number of patients in the dose-escalation and backfill cohorts. If the number of patients at the current dose reaches this criteria and the same dose level is recommended as the next dose level, the study is terminated. The default value is stopping.npts=12.

suspend

The suspension rule that holds off the decision on dose allocation for the dose-escalation cohort until sufficient toxicity information is available. For example, setting as 0.33 which means one-third of the patients had not completed the toxicity evaluation at the current dose level in the dose escalation cohort. The default value suspend=0 essentially turns off this type of suspending rule, that is all patients should complete the toxicity evaluation at the current dose level in the dose escalation cohort

stopping.prob.T

Early study termination criteria for toxicity, taking a value between 0 and 1. If the posterior probability that toxicity outcome is less than the target toxicity probability (target_T) is larger than this criteria, the dose levels are eliminated from the study. The default value is stopping.prob.T=0.95.

stopping.prob.E

Early study termination criteria for efficacy, taking a value between 0 and 1. If the posterior probability that efficacy outcome is less than the minimum efficacy probability (target_E) is larger than this criteria, the dose levels are eliminated from the study. The default value is stopping.prob.E=0.90.

ppsi01

Score for toxicity=yes and efficacy=no in utility defined by scoring.The default value is psi01=0.

ppsi00

Score for toxicity=no and efficacy=no in utility defined by scoring. The default value is psi00=40.

ppsi11

Score for toxicity=yes and efficacy=yes in utility defined by scoring. The default value is psi11=60.

ppsi10

Score for toxicity=no and efficacy=yes in utility defined by scoring. The default value is psi10=100.

n.sim

Number of simulated trial. The default value is n.sim=1000.

seed.sim

Seed for random number generator. The default value is seed.sim=100.

Details

The backboinet is a function which generates the operating characteristics of the backfill bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization by a simulation study. Users can specify a variety of study settings to simulate studies. The operating characteristics of the design are summarized by the percentage of times that each dose level was selected as optimal biological dose and the average number of patients who were treated at each dose level. The percentage of times that the study was terminated and the expected study duration are also provided.

Value

The backboinet returns a list containing the following components:

toxprob

True toxicity probability.

effprob

True efficacy probability.

phi

Target toxicity probability.

delta

Target efficacy probability.

lambda1

Lower toxicity boundary in dose escalation/de-escalation.

lambda2

Upper toxicity boundary in dose escalation/de-escalation.

eta1

Lower efficacy boundary in dose escalation/de-escalation.

tau.T

Toxicity assessment windows (months).

tau.E

Efficacy assessment windows (months).

suspend

The suspension rule that holds off the decision on dose allocation for the dose-escalation cohort until sufficient toxicity information is available.

accrual

Accrual rate (months) (patient accrual rate per month).

n.patient

Average number of patients who were treated at each dose level

n.bpatient

Average number of back filled patients who were treated at each dose level

prop.select

Percentage of times that each dose level was selected as optimal biological dose.

prop.stop

Percentage of times that the study was terminated.

duration

Expected study duration (months)

totaln

Total patients

data.obs.n

Record the number of patients in each dose level within the simulations during the trial

obd

Record the optimal dose in each simulation during the trial

backfilltimes

Record how may times we back-filled during the trial

backfillcount

Record the number of back-filled patients in dose level within the simulations during the trial

PCS

The percentage of trials that the optimal dose was correctly selected.

PCA

The percentage of patients that were correctly allocated to the optimal dose.

PTS

The percentage of toxic doses selection.

PTA

The percentage of patients who were allocated to toxic doses.

References

BF-BOIN-ET: A backfill Bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization.

Examples

target_T=0.3
target_E=0.25
toxprob=c(0.03,0.05,0.2,0.22,0.45)
effprob=c(0.05,0.1,0.5,0.68,0.7)

get.oc.backboinet(target_T=target_T, toxprob=toxprob,target_E=target_E,
effprob=effprob,n.dose=5,startdose=1,ncohort=10,cohortsize=3,
pT.saf=0.6 * target_T,pT.tox = 1.4 * target_T,pE.saf = 0.6 * target_E,
alpha.T1=0.5,alpha.E1=0.5,tau.T=1,tau.E=1,te.corr=0.2,
gen.event.time="weibull",accrual=3,gen.enroll.time="uniform",n.earlystop=6,
stopping.npts=12,suspend=0,stopping.prob.T=0.95,stopping.prob.E=0.90,
ppsi01=0,ppsi00=40,ppsi11=60,ppsi10=100,n.sim=2,seed.sim=100)

backboinetr

Description

Obtain the operating characteristics of the backfill bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization within random scenarios

Usage

get.oc.backboinetr(
  target_T = 0.3,
  target_Tr = 0.359,
  target_E = 0.25,
  target_Er = 0.197,
  n.dose,
  startdose,
  ncohort,
  cohortsize,
  pT.saf = 0.6 * target_T,
  pT.tox = 1.4 * target_T,
  pE.saf = 0.6 * target_E,
  alpha.T1 = 0.5,
  alpha.E1 = 0.5,
  tau.T,
  tau.E,
  te.corr = 0.2,
  gen.event.time = "weibull",
  accrual,
  gen.enroll.time = "uniform",
  n.earlystop = 6,
  stopping.npts = 12,
  suspend = 0,
  stopping.prob.T = 0.95,
  stopping.prob.E = 0.9,
  ppsi01 = 0,
  ppsi00 = 40,
  ppsi11 = 60,
  ppsi10 = 100,
  n.sim = 10000,
  seed.sim = 30
)

Arguments

target_T

Target toxicity probability. The default value is target_T=0.3. When observing 1 DLT out of 3 patients and the target DLT rate is between 0.25 and 0.279, the decision is to stay at the current dose due to a widely accepted practice.

target_Tr

The upper boundary for the toxicity when generating the random scenarios. The default value is target_Tr=0.359.

target_E

The minimum required efficacy probability. The default value is target_E=0.25.

target_Er

The lower boundary for the efficacy when generating the random scenarios. The default value is target_Er=0.197.

n.dose

Number of dose.

startdose

Starting dose. The lowest dose is generally recommended.

ncohort

Number of cohort.

cohortsize

Cohort size.

pT.saf

Highest toxicity probability that is deemed sub-therapeutic such that dose-escalation should be pursued. The default value is pT.saf=target_T*0.6.

pT.tox

Lowest toxicity probability that is deemed overly toxic such that dose de-escalation is needed. The default value is pT.tox=target_T*1.4.

pE.saf

Minimum probability deemed efficacious such that the dose levels with less than delta1 are considered sub-therapeutic. The default value is pE.saf=target_E*0.6.

alpha.T1

Probability that toxicity event occurs in the late half of toxicity assessment window. The default value is alpha.T1=0.5.

alpha.E1

Probability that efficacy event occurs in the late half of assessment window. The default value is alpha.E1=0.5.

tau.T

Toxicity assessment windows (months).

tau.E

Efficacy assessment windows (months).

te.corr

Correlation between toxicity and efficacy probability, specified as Gaussian copula parameter. The default value is te.corr=0.2.

gen.event.time

Method to generate the time to first toxicity and efficacy outcome. Weibull distribution is used when gen.event.time ="weibull". Uniform distribution is used when gen.event.time="uniform". The default value is gen.event.time="weibull".

accrual

Accrual rate (months) (patient accrual rate per month).

gen.enroll.time

Method to generate enrollment time. Uniform distribution is used when gen.enroll.time="uniform". Exponential distribution is used when gen.enroll.time="exponential". The default value is gen.enroll.time="uniform".

n.earlystop

the early stopping parameter. If the number of patients treated at the current dose reaches n.earlystop,stop the trial and select the optimal dose (OD) based on the observed data.The default value is n.earlystop=6.

stopping.npts

Early study termination criteria for the number of patients in the dose-escalation and backfill cohorts. If the number of patients at the current dose reaches this criteria and the same dose level is recommended as the next dose level, the study is terminated. The default value is stopping.npts=12.

suspend

the suspension rule that holds off the decision on dose allocation for the dose-escalation cohort until sufficient toxicity information is available. For example, setting as 0.33 which means one-third of the patients had not completed the toxicity evaluation at the current dose level in the dose escalation cohort. The default value suspend=0 essentially turns off this type of suspending rule, that is all patients should complete the toxicity evaluation at the current dose level in the dose escalation cohort

stopping.prob.T

Early study termination criteria for toxicity, taking a value between 0 and 1. If the posterior probability that toxicity outcome is less than the target toxicity probability (target_T) is larger than this criteria, the dose levels are eliminated from the study. The default value is stopping.prob.T=0.95.

stopping.prob.E

Early study termination criteria for efficacy, taking a value between 0 and 1. If the posterior probability that efficacy outcome is less than the minimum efficacy probability (target_E) is larger than this criteria, the dose levels are eliminated from the study. The default value is stopping.prob.E=0.90.

ppsi01

Score for toxicity=yes and efficacy=no in utility defined by scoring.The default value is psi01=0.

ppsi00

Score for toxicity=no and efficacy=no in utility defined by scoring. The default value is psi00=40.

ppsi11

Score for toxicity=yes and efficacy=yes in utility defined by scoring. The default value is psi11=60.

ppsi10

Score for toxicity=no and efficacy=yes in utility defined by scoring. The default value is psi10=100.

n.sim

Number of simulated trial. The default value is n.sim=10000.

seed.sim

Seed for random number generator. The default value is seed.sim=30.

Details

The backboinetr is a function which generates the operating characteristics of the backfill bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization by a simulation study. Users can specify a variety of study settings to simulate studies. The operating characteristics of the design are summarized by the percentage of times that each dose level was selected as optimal biological dose and the average number of patients who were treated at each dose level. The percentage of times that the study was terminated and the expected study duration are also provided.

Value

The backboinetr returns a list containing the following components:

toxprob

The random true toxicity probability.

effprob

The random true efficacy probability.

phi

Target toxicity probability.

delta

Target efficacy probability.

target_Tr

The upper boundary for the toxicity when generating the random scenarios.

target_Er

The lower boundary for the efficacy when generating the random scenarios.

bd.true

The target optimal dose (OD) level when generating the random scenarios.

mtd.true

The maximum tolerated dose (MTD) level when generating the random scenarios.

lambda1

Lower toxicity boundary in dose escalation/de-escalation.

lambda2

Upper toxicity boundary in dose escalation/de-escalation.

eta1

Lower efficacy boundary in dose escalation/de-escalation.

tau.T

Toxicity assessment windows (months).

tau.E

Efficacy assessment windows (months).

suspend

The suspension rule that holds off the decision on dose allocation for the dose-escalation cohort until sufficient toxicity information is available.

accrual

Accrual rate (months) (patient accrual rate per month).

duration

Expected study duration (months)

totaln

Total patients

data.obs.n

Record the number of patients in each dose level within the simulations during the trial

obd

Record the optimal dose in each simulation during the trial

backfilltimes

Record how may times we back-filled during the trial

backfillcount

Record the number of back-filled patients in dose level within the simulations during the trial

PCS

The percentage of trials that the optimal dose was correctly selected.

PCA

The percentage of patients that were correctly allocated to the optimal dose.

PTS

The percentage of toxic doses selection.

PTA

The percentage of patients who were allocated to toxic doses.

References

BF-BOIN-ET: A backfill Bayesian optimal interval design using efficacy and toxicity outcomes for dose optimization.

Examples

target_T=0.3
target_E=0.25

get.oc.backboinetr(target_T=target_T,target_Tr=0.359,target_E=target_E,
target_Er=0.197,n.dose=5,startdose=1,ncohort=10,cohortsize=3,
pT.saf=0.6 * target_T,pT.tox = 1.4 * target_T,pE.saf = 0.6 * target_E,
alpha.T1=0.5,alpha.E1=0.5,tau.T=1,tau.E=1,te.corr=0.2,
gen.event.time="weibull",accrual=3,gen.enroll.time="uniform",n.earlystop=6,
stopping.npts=12,suspend=0,stopping.prob.T=0.95,stopping.prob.E=0.90,
ppsi01=0,ppsi00=40,ppsi11=60,ppsi10=100,n.sim=2,seed.sim=30)