Rethinking Tolerability Measurement in Oncology Trials

 Bill Byrom, PhD | John Devin Peipert, PhD 

The bottom line: Current PRO measures in oncology trials describe toxicity well. They don't tell you whether a patient can actually tolerate treatment. That gap has real consequences for dose optimization and regulatory submissions.

Patient-reported outcome measures have become essential in oncology drug development, but critical methodological gaps limit the conclusions sponsors can draw from the data patients provide. With FDA's Project Optimus and patient-focused drug development guidance raising the bar for dose optimization evidence, resolving these gaps is increasingly urgent.

In this peer-reviewed commentary published in Cancer Control, Signant Health's Dr. Bill Byrom and University of Birmingham's Dr. John Devin Peipert examine three unresolved methodological issues, including:

• Why current PRO measures capture toxicity severity but fall short of measuring true tolerability
• How to develop evidence-based tolerability thresholds anchored to observable clinical endpoints
• The case for direct tolerability measures alongside PRO-CTCAE and GP5
• Why baseline GP5 assessment creates interpretive challenges and what to do about it

Go deeper: Watch the on-demand expert panel discussion Measuring Treatment Tolerability in Oncology where Byrom and Peipert are joined by industry and academic leaders.