Phase II cancer clinical trials for biomarker-guided treatments

Diversity in Oncology Clinical Trials: Current Landscape for Industry-Sponsored Clinical Trials in Asia

INTRODUCTION

There has been a growing recognition on the importance of diversity in clinical trials. Existing research has highlighted a significant demographic imbalance. Amidst this renewed focus on diversity, it is crucial to acknowledge that Asia comprises over half of the world's population. Given the region's demographic significance, we sought to compare various characteristics and growth rates for trials with sites in Asia against those without any sites in Asia.

METHODS

We performed comprehensive analyses of industry-sponsored phase 2 and 3 oncology trials registered at Clinicaltrials.gov, using drugs or biologics as investigational agents and executed between 1 January 2018 and 31 December 2022. We applied the compound annual growth rate (CAGR) as an analytical tool to track the trial growth rates over this 5-year period.

RESULTS

We identified 894 industry-sponsored phase 2 and 3 cancer studies with available study location data. Out of these, 415 trials (46.42%) had study sites in Asia. Notably, these trials with sites in Asia were also more likely to be phase 3 trials (39.76% vs 6.47%, p < 0.001), include female and paediatric populations, and be randomised trials. Interestingly, lung and stomach cancers were more commonly studied in these trials, while myeloma was less commonly studied. The number of trial sites for liver cancer was not significantly higher for Asia, even though the incidence of the disease is much higher in this region. Despite an overall declining trend in the number of clinical trials in the last 5 years, we observed a transitional positive increase in the CAGR from 2020 to 2021 for trials with sites in Asia. However, East Asia, specifically China, exhibited a disproportionate overrepresentation in these trials.

CONCLUSIONS

There are notable characteristics of clinical trials with sites in Asia. Comprehending these disparities may aid in the strategic planning to enhance a balanced representation of ethnicities in trials.

Design and Analysis of Cancer Clinical Trials for Personalized Medicine

Biomarkers play a key role in the development of personalized medicine. Cancer clinical trials with biomarker should be appropriately designed and analyzed reflecting the various factors, such as the phase of trials, the type of biomarker, the study objectives, and whether the used biomarker is already validated or not. In this paper, we demonstrate design and analysis of two phase II cancer clinical trials, one with a predictive biomarker and the other with a prognostic biomarker. A statistical testing method and its sample size calculation method are presented for each of the trials. We assume that the primary endpoint of these trials is a time to event variable, but this concept can be used for any type of endpoint with associated testing methods. The test statistics and their sample size formulas are derived using the large sample approximation based on the martingale central limit theorem. Using simulations, we find that the test statistics control the type I error rate accurately and the sample sizes calculated using the formulas maintain the statistical power specified at the design stage.