Kaplan-Meier Progression-Free Survival (Simulated Cohort)
Hazard Ratio: 0.88
Control Arm (Standard of Care)
Investigational Arm (Etcamah)
Biomarker Enrichment Disconnect: A drug may demonstrate compelling targeted efficacy in a narrow biomarker-positive subpopulation (accelerated approval basis). When expanded into broader or heterogeneous intention-to-treat (ITT) populations, dilution of effect size (HR 0.88) can lower observed statistical power below acceptable detection thresholds.
Trial Parameters & Sensitivity
Hazard Ratio (HR)
0.88
Sample Size (Enrolled ITT Patients)
750
Mutation Prevalence (Target Biomarker)
22%
Biomarker Assay Sensitivity
85%
Computed Power (1 - β)
0.62
Target ≥ 0.80
Events Observed (d)
412
PFS endpoint events
Screened Patients
638
Yield from sensitivity
Two-Sided Alpha (α)
0.05
Significance threshold
Missed Primary Goal (p = 0.094)
Increase sample size by 28% to achieve 80% power at current hazard ratio.