This short communication presents a first in human Bayesian Optimal Interval design case study. The study design and associated operating characteristics are discussed, together with study amendments proposed whilst the study was ongoing. Simulations investigating the impact of the amendments on the operating characteristics of the study design are presented. Lessons learnt from the case study, including providing practical advice when designing smarter early phase oncology trials to identify the maximum tolerate dose are also summarised. It is argued that model‐assisted designs are simple to implement, flexible and perform significantly better than the commonly used “3 + 3” design, and thus should become the go to design for statisticians when limited information is known about the dose toxicity curve.

This short communication supports that rule-based study designs such as the '3 + 3' study design are still being used in early phase oncology development programs despite their inferior performance to model-based and model-assisted designs. Statisticians have an opportunity to shape and improve early phase oncology drug development programs by introducing newer, more efficient study designs that estimate the Optimal Biological dose to their oncology trialist colleges.

Historically early phase oncology drug development programmes have been based on the belief that “more is better”. Furthermore, rule‐based study designs such as the “3 + 3” design are still often used to identify the MTD. Phillips and Clark argue that newer Bayesian model‐assisted designs such as the BOIN design should become the go to designs for statisticians for MTD finding. This short communication goes one stage further and argues that Bayesian model‐assisted designs such as the BOIN12 which balances risk‐benefit should be included as one of the go to designs for early phase oncology trials, depending on the study objectives. Identifying the optimal biological dose for future research for many modern targeted drugs, immunotherapies, cell therapies and vaccine therapies can save significant time and resources.