Fig 1.
BioPETsurv analysis of a modestly prognostic biomarker for a fixed-duration 36-month or 48-month trial.
Investigators are considering the biomarker for enrichment of either a 36-month or 48-month trial and specified 90% power to detect a hazard ratio of 0.8 using two-sided testing and α = 0.05. For cost analysis, the cost of screening was $500 and the cost of one patient in the trial was $4000 (36-month trial) and $5000 (48-month trial). The biomarker in this example has HR≈1.2 corresponding to a 1 SD difference in the marker.
Table 1.
BioPETsurv analysis of a modestly prognostic biomarker (Example 1).
Fig 2.
BioPETsurv analysis of simulated biomarker for a trial with a 12-month accrual period and 36-month follow-up period.
Investigators are planning a trial with a 12-month accrual period plus a 36-month follow-up period, and anticipate having a marker with HR≈2.8 corresponding to a 1 standard deviation difference in the marker. The BioPETsurv data simulator generated data for a normally distributed biomarker with this prognostic strength. Sample size calculations specified 90% power to detect a treatment hazard ratio of 0.8 using two-sided testing and α = 0.05. For cost analysis, patient screening cost was $300 and the cost of a patient in a trial was $100/month before the clinical endpoint. Numeric results are in Table 2.
Table 2.
BioPETsurv analysis of simulated biomarker for a trial with a 12-month accrual period and 36-month follow-up period (Example 2).