Abstract 2516: A qualitative research study on hematology and oncology consultants’ experiences and opinions on using minimal residual disease (MRD) as a fast-track approval endpoint in early-phase clinical trials in multiple myeloma in Saudi Arabia
Authors: Albandari A. Alnasser, Tariq H. Alqurayshah
Journal: Cancer Research (2025)

Introduction: The US FDA has recently considered minimal residual disease (MRD) as an acceptable accelerated approval endpoint in multiple myeloma (MM). Meta-analysis studies have shown the clinical benefit of MRD negativity in MM. Objective: This qualitative research study aims to assess the opinions and experiences of hematology and oncology consultants in Saudi Arabia on MRD as an intermediate endpoint for fast-track drug approvals by the Saudi Food and Drug Authority in MM. Study Design: Interviewing 30 registered physicians with more than one year of experience. The interviews will be conducted through a single focus group and several face-to-face interviews or performed online. The predetermined set of semi-structured questions will cover topics such as the definition of MRD, its clinical and research significance, MRD detection thresholds, duration of MRD negativity, and its correlation with other clinical endpoints, such as progression free survival (PFS) and overall survival (OS). The interviews will be conducted by scientific oncology and hematology evaluation experts at the Saudi Food and Drug Authority. Before starting any interview, participants will complete consent forms, including the study’s goals and who will conduct the study. Results: First focus group included seven consultants and highlighted MRD’s value as a surrogate endpoint, emphasizing its strong correlation with PFS and OS. MRD negativity is associated with improved PFS and OS across all disease stages, including newly diagnosed and relapse/refractory multiple myeloma. It is particularly valuable in early phase trials for evaluating novel therapies and in maintenance therapy for monitoring sustained remission. However, the use of MRD as a surrogate endpoint for drug approval remains debated. While it is considered as a good endpoint for expedited approvals of MM new medicinal products and indications but not a perfect surrogate for overall survival. The focus group emphasized that while MRD is a valuable indicator, it does not replace the need for collecting and analyzing OS and PFS data to confirm long term benefit for patients. In Saudi Arabia, methods for detecting MRD include flow cytometry and next-generation sequencing (NGS). Flow cytometry is the most accessible and cost-effective method, widely available in many hospitals. The threshold for MRD negativity depends significantly on the detection method used, as each method offering varying level of sensitivity. Flow cytometry typically achieves a sensitive threshold 10-5. Also, next-generation sequencing (NGS) can achieve a higher sensitivity of up 10-6. Conclusion: MRD could be a promising surrogate endpoint in multiple myeloma due to its strong association with PFS and OS with the need for the long-term clinical data. Citation Format: Albandari A. Alnasser, Tariq H. Alqurayshah. A qualitative research study on hematology and oncology consultants’ experiences and opinions on using minimal residual disease (MRD) as a fast-track approval endpoint in early-phase clinical trials in multiple myeloma in Saudi Arabia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2516.