Epgo23_normal

In the setting of Case 2: Strategy 2/2( + 1); at least two trials significant (and the
treatment effect of the other one at least showing in the same direction) this function calculates the probability that a third phase III trial is necessary.

internal

Plan optimal sample size allocation and go/no-go decision rules
for phase II/III drug development programs with time-to-event, binary or
normally distributed endpoints when assuming fixed treatment effects or a
prior distribution for the treatment effect, using methods from Kirchner et al.
(2016) <doi:10.1002/sim.6624> and Preussler (2020). Optimal is in the sense of
maximal expected utility, where the utility is a function taking into account
the expected cost and benefit of the program. It is possible to extend to more
complex settings with bias correction (Preussler S et al. (2020)
<doi:10.1186/s12874-020-01093-w>), multiple phase III trials (Preussler et
al. (2019) <doi:10.1002/bimj.201700241>), multi-arm trials (Preussler et al.
(2019) <doi:10.1080/19466315.2019.1702092>), and multiple endpoints
(Kieser et al. (2018) <doi:10.1002/pst.1861>).

Lukas D. Sauer

drugdevelopR

Utility-Based Optimal Phase II/III Drug Development Planning

Stella Erdmann

Johannes Cepicka

Marietta Kirchner

Meinhard Kieser

Epgo23_normal function

<dl><dt>kappa</dt>
<dd>threshold value for the go/no-go decision rule</dd>
<dt>n2</dt>
<dd>total sample size for phase II; must be even number</dd>
<dt>alpha</dt>
<dd>significance level</dd>
<dt>beta</dt>
<dd><code>1-beta</code> power for calculation of sample size for phase III</dd>
<dt>a</dt>
<dd>lower boundary for the truncation</dd>
<dt>b</dt>
<dd>upper boundary for the truncation</dd>
<dt>w</dt>
<dd>weight for mixture prior distribution</dd>
<dt>Delta1</dt>
<dd>assumed true treatment effect for standardized difference in means</dd>
<dt>Delta2</dt>
<dd>assumed true treatment effect for standardized difference in means</dd>
<dt>in1</dt>
<dd>amount of information for <code>Delta1</code> in terms of sample size</dd>
<dt>in2</dt>
<dd>amount of information for <code>Delta2</code> in terms of sample size</dd></dl>

Arguments

Expected probability to do third phase III trial — Epgo23_normal

<dl>

<dt>kappa</dt>
<dd>threshold value for the go/no-go decision rule</dd>


<dt>n2</dt>
<dd>total sample size for phase II; must be even number</dd>


<dt>alpha</dt>
<dd>significance level</dd>


<dt>beta</dt>
<dd><code>1-beta</code> power for calculation of sample size for phase III</dd>


<dt>a</dt>
<dd>lower boundary for the truncation</dd>


<dt>b</dt>
<dd>upper boundary for the truncation</dd>


<dt>w</dt>
<dd>weight for mixture prior distribution</dd>


<dt>Delta1</dt>
<dd>assumed true treatment effect for standardized difference in means</dd>


<dt>Delta2</dt>
<dd>assumed true treatment effect for standardized difference in means</dd>


<dt>in1</dt>
<dd>amount of information for <code>Delta1</code> in terms of sample size</dd>


<dt>in2</dt>
<dd>amount of information for <code>Delta2</code> in terms of sample size</dd>

</dl>

Epgo23_normal: Expected probability to do third phase III trial

Description

Usage

Value

Arguments

Examples