Developing new cancer medicines takes years of research and testing. A key step in ensuring patients can access these medicines is the reimbursement decision: whether the medicine will be paid for by the healthcare system. Since April 2025, Belgian patient organizations have a voice in these decisions, so patient perspectives are included when evaluating new treatments. To contribute effectively, it helps to understand how efficacy and safety are measured in clinical trials.
What does “efficacy” mean in cancer trials?
- The most important measure is overall survival (OS): whether people live longer with the new medicine than with the current standard treatment.
- Sometimes it takes many years to prove a clear survival benefit. To avoid delaying access to promising treatments, doctors, regulators and payers also look at other measures that can be assessed sooner.
Useful early indicators (intermediate endpoints)
These are results that can be seen earlier in a trial and may signal that a treatment is working:
- Disease-free survival (DFS): time without the cancer coming back after treatment.
- Progression-free survival (PFS): time without the cancer getting worse.
- Pathologic complete response (pCR): no cancer cells found in the tissue removed after treatment (often measured before surgery).
Why these measures matter to patients
In a recent advisory board with Belgian oncology patient organizations, Prof. Sandrine Aspeslagh (oncologist at UZ Brussel) explained these early indicators in simple terms. Participants discussed how they can bring hope and reduce uncertainty—for example, by delaying relapse or keeping the disease stable—while also emphasizing that quality of life is essential. They shared views on how