Inputs:

• Null hypothesis proportion (p0): Specify the expected proportion under the null hypothesis.
• Alternative hypothesis proportion (pA): Define the expected proportion under the alternative hypothesis.
• Type II error rate (beta): Set the desired maximum probability of failing to detect a true treatment effect.
• Type I error rate (alpha): Determine the desired level of significance or the probability of incorrectly rejecting the null hypothesis.

Outputs:

• Sample size at Stage 1 (n1): Obtain the optimal sample size for the first stage of the clinical trial.
• Sample size at Stage 2 (n): Determine the optimal sample size for the second stage of the clinical trial.
• Decision boundaries at Stage 1 (r1): Identify the criterion for early termination or continuation of the trial at the first stage based on observed response rates.
• Decision boundaries at Stage 2 (r): Establish the criterion for early termination or continuation of the trial at the second stage based on observed response rates.
• Expected sample size under the null hypothesis (EN(p0)): Calculate the expected sample size assuming the null hypothesis is true.
• Probability of early termination under the null hypothesis (PET (p0)): Determine the probability of early termination assuming the null hypothesis is true.
• Range of admissible probability values (qLo and qHi): Identify the range of probability values for which the particular design is considered admissible.