Assessing activity in early-phase trials in oncology: current designs for expansion cohorts and phase 2

December 2, 2021

Be updated on different types of Bayesian and frequentist designs that may be used for expansion cohorts in phase 1 trials and in single-arm and randomized phase 2 trials in oncology.

THURSDAY, DECEMBER 2 – 17:00 – 18:00 CET | 11:00 – 12:00 EDT



Historically, single-arm phase 2 trials have been used in oncology in order to confirm tolerability and safety observed in phase 1, and to obtain evidence of activity in specific histological types. Randomized phase 2 trials became increasingly common over the past two decades and have mainly aimed at improving go/no-go decisions to move to phase 3. In parallel, the advent of precision medicine led to two major changes in the landscape of phase 2 trials. The first has been the introduction of master protocols, such as umbrella, basket and phase 2 platform trials, which have their design focused not only on the experimental treatment, but also on the biomarkers. The second major change has been the increasing ability to assess activity in early-phase trials, given the expected low toxicity and high selectivity of treatments and the focus on targeted populations. This led to expansion cohorts, which are often designed using principles that are applicable to phase 2 trials.

In this webinar, our goal is to review different types of Bayesian and frequentist designs that may be used for expansion cohorts in phase 1 trials and in single-arm and randomized phase 2 trials in oncology.

– We will start by reviewing the recent evolution and general trends in the design of early-phase trials to investigate the activity of targeted agents and immunotherapy.
– We will then summarize the most salient features of Bayesian and frequentist designs in this setting.
– Finally, we will cover different statistical caveats, including early consideration of randomization, issues related to sample-size calculation and the efficient use of biomarkers.



  • Be updated on current trends in expansion cohorts and phase-2 designs in oncology
  • Gain insights into the advantages and disadvantages of various Bayesian and frequentist approaches to the design of early-phase trials to assess activity


Elisabeth (Els) Coart, PhD, Principal Biostatistician, Consulting Services, IDDI.

• Els graduated in Bio-engineering at KU Leuven in 1995, got her PhD in Molecular Genetics in 2003 at Ghent University, and a Master’s degree in Biostatistics also at Ghent University, in 2007.
• After some years of experience in research and clinical biostatistics in diagnostic companies, Els joined IDDI in 2011, where she conducted research related to biomarkers in Alzheimer’s disease and validation of surrogate endpoints in advanced colorectal cancer. In 2015, Els joined the team of consultants at IDDI, led by the company founder, Marc Buyse. She served as Director, Consulting Services, from 2017 to 2019 and now focusses on consultancy activities.
• As a consultant, Els has helped a large number of pharmaceutical and biotechnology companies to design, implement and analyze clinical trials for drug development, with a focus on oncology and biomarkers. She is particularly interested in early-phase trials using frequentist and Bayesian methods, as well as phase trials with biomarker-driven designs. Moreover, given her strong background in assay development she is IDDI’s expert in analytical and clinical validation of in-vitro diagnostics.
• Els has published more extensively in Alzheimer’s disease, biomarkers, and oncology.

Everardo Saad, MD, Medical Director at the International Drug Development Institute, IDDI.

• He has nearly 20 years of experience in Medical Oncology and clinical-trial design.
• He graduated in Medicine and trained in Internal Medicine in Sao Paulo, and did his fellowship in Medical Oncology at the University of Texas M.D. Anderson Cancer Center, in Houston.
• After practicing for several years, he shifted his professional career towards education and research in Medical Oncology, and has a special interest in clinical trial methodology, the assessment of endpoint, and the development of novel therapies for cancer patients.