biostats / clinical trial modeling experience

Hi everyone! Hoping to get some guidance from folks with biostats / clinical trial modeling experience.

I recently came across an equity research report that used Monte Carlo simulation to estimate hazard ratios and probability of success for a Phase III oncology trial. I understand the high-level statistical assumptions (alpha allocation between interim and final analyses, endpoints like PFS and OS, etc.), but I’d like to actually recreate something similar in Excel to better understand the mechanics.

Specifically, I’m trying to figure out:

• How to simulate time-to-event data (such as PFS/OS) under different hazard ratio assumptions
• How to incorporate alpha splitting between interim and final analyses
• How to run Monte Carlo simulations to estimate probability of success
• How to model the timing of events (like when the required number of events is reached)

I’m not sure how to structure this in Excel, especially the event-time simulation and linking it to interim/final analyses.

If anyone has experience building this kind of model, I’d really appreciate pointers, templates, or resources to get started.

Thanks again!