Finding a consensus on time-to-event endpoints definitions in marginal zone lymphoma: A Delphi method.

Area of Science:

• Hematology
• Clinical Trials Methodology
• Oncology

Background:

• Systematic reviews reveal significant heterogeneity in primary and secondary endpoint definitions within marginal zone lymphoma (MZL) clinical trials, impeding cross-trial comparability.
• This study aimed to establish consensus on definitions for four key time-to-event endpoints in MZL trials through a Delphi process involving international experts.

Discussion:

• A panel of 105 experts participated in sequential questionnaires to define progression-free survival (PFS), event-free survival (EFS), time-to-failure (TTF), and time-to-next-treatment (TTNT).
• Consensus (>80% agreement) was achieved for PFS, TTNT, and TTF after Rounds 1 and 2, respectively.
• Disagreement persisted regarding the definition of EFS, specifically concerning the inclusion of 'treatment discontinuation' as an event.

Key Insights:

• Standardized definitions for PFS, TTNT, and TTF were successfully established for MZL clinical trials.
• The Delphi process highlighted persistent challenges in defining EFS, indicating a need for further refinement.
• The study underscores the critical importance of consistent endpoint definitions for enhancing the reliability and interpretability of MZL research.

Outlook:

• Revised standardized definitions are anticipated for presentation at the upcoming International Conference on Malignant Lymphoma in 2023.
• The findings aim to improve the consistency and comparability of future MZL clinical trials.
• Further efforts are needed to resolve discrepancies in EFS definitions to ensure comprehensive outcome assessment.