PPoS

PPoS computes conditional power (CP), predictive power of success (PPoS), and probability of success (PoS) to assess the likelihood of clinical trial success across continuous, binary, and time-to-event endpoints.

Key Features:

• CP, PPoS, PoS computation: Calculates conditional power (CP), predictive power of success (PPoS), and probability of success (PoS) for trial assessments.
• Endpoint coverage: Provides analytic expressions for continuous, binary, and time-to-event endpoints.
• Trial configurations: Covers both single-arm and two-arm trial designs.
• Single-arm time-to-event derivation: Derives CP/PPoS/PoS for single-arm trials with time-to-event endpoints and provides an alternative expression for the variance of log(median).
• Binomial endpoints with beta prior: Derives PPoS calculations for binomial endpoints using a beta prior distribution.
• Consolidation of definitions: Consolidates inconsistent definitions of CP, PPoS, and PoS from the literature into derived expressions.
• Implementation: Implements the derived expressions in the LongCART package in R.

Scientific Applications:

• Interim monitoring: Inform interim monitoring and go/no-go decisions in clinical trials using CP, PPoS, and PoS.
• Sample size and resource allocation: Support sample size re-estimation and resource allocation by quantifying success probabilities across endpoints.
• Single-arm time-to-event analysis: Provide accurate uncertainty quantification for single-arm time-to-event studies via a corrected variance for log(median).
• Bayesian predictive assessment for binomial endpoints: Enable Bayesian predictive assessments for binomial endpoints via beta prior–based PPoS calculations.
• Methodological reference: Serve as a reference for derivations addressing inconsistencies in statistical definitions of trial success measures.

Methodology:

Analytical derivation of expressions for CP, PPoS, and PoS for continuous, binary, and time-to-event endpoints; derivation for single-arm time-to-event including an alternative variance expression for log(median); derivation of PPoS for binomial endpoints using a beta prior; and implementation of the derived expressions in the LongCART R package.