PS51: Leveraging Duration of Response: Enhancing Efficiency in Treatment Effect Quantification and Predictability for Go/No-Go Decisions in Oncology Trials

Duration of Response (DOR) is a clinically important endpoint for evaluating treatment effects in oncology clinical trials. It can be measured earlier than the traditional endpoint overall survival (OS) and may significantly help expedite the drug development in oncology and therefore draws great attention in recent years. In early-phase studies, DOR combined with objective response rate (ORR), are frequently used to predict the treatment's potential benefit in OS and serves as the primary efficacy endpoint for Go/No-Go decisions regarding further drug development. The conventional DOR analysis includes only responders and therefore is susceptible to selection bias, as subsets of responding patients may differ in baseline prognostic factors and comparison of DOR between groups will not be based on randomized patients. Recent advance in analysis of DOR which may be based on intent to treat patient population has the potential to overcome this issue and therefore make direct input in the regulatory evaluation for oncology drug development. Additionally, the development of combination therapies adds another layer of complexity in evaluating and predicting efficacy using early endpoints such as ORR and DOR. Innovative methodologies are required to address this challenge, including predicting the effects of combination treatments based on monotherapy data and estimating monotherapy efficacy from combination therapy data. In this session, speakers from biopharmaceutical industry and FDA will share their insights, experience, and recent development in leveraging DOR for enhancing efficiency in treatment effect quantification and predictability for Go/No Go decisions, as well as exploration of its association with long term clinical endpoints in oncology trials. Specifically, the topics presented by speakers include DOR analysis for assessing treatment effects in comparative clinical studies, predicting combination treatment effects for DOR in oncology drug development, integrating ORR and DOR using win ratio for Go/No Go decisions for Phase 3 trial planning, and evaluating the association of DOR with long term clinical endpoints in comparative clinical trials. This session aims to advance our understanding of and explore potential uses for early endpoint DOR in oncology trials and expedite drug development.