In 2015, the European Society for Medical Oncology (ESMO) introduced the ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS), a validated tool to stratify the magnitude of clinical benefit derived from therapeutic approaches in a standardized way. With the rapid increase in new treatment options and expanding cancer care costs, the ESMO-MCBS can assist as a tool for health technology assessment. Every new anticancer medicine that receives approval from the European Medicines Agency (EMA) and the United States Food and Drug Administration (FDA) is graded and assigned a score, which is publicly available on the ESMO website. The highest grades of the ESMO-MCBS in the curative setting are A and B, and in the non-curative setting are 5 and 4; these indicate medicines with substantial clinical benefit. In 2017, ESMO-MCBS version 1.1 was published, incorporating several revisions and the ability to score single-arm studies.

The ESMO-MCBS is based on the concept that the potential benefits of a new treatment are not only to live longer, reflected by improved overall survival (OS) or surrogates such as disease-free survival (DFS) or progression-free survival (PFS) when validated, but also to live better, reflected by improved quality of life (QoL) or reduced toxicity compared to the previous standard of care. There are different settings in which QoL can determine the final ESMO-MCBS score. For new adjuvant or potentially curative therapies, the combination of non-inferior OS or DFS with improved QoL results in a grade B (form 1). New treatment approaches not likely to be curative with OS or PFS as the primary endpoint receive a preliminary score based on OS or PFS benefit and are credited with an upgrade of 1 point if QoL is improved (forms 2a and 2b). Scores generated on PFS may also be downgraded in cases where there is no survival advantage with mature data and where QoL evaluation has not demonstrated any significant and clinically meaningful benefit. Furthermore, in non-inferiority studies with non-curative treatment approaches that have toxicity or QoL as the primary endpoint, a treatment option can receive a grade 4 if QoL is improved and OS or PFS is at least non-inferior to the previous standard of care, and a grade 3 if there is an improvement in some pre-specified symptoms but not in overall QoL (form 2c). Finally, for single-arm studies for orphan diseases or situations with a high unmet need, the preliminary score, which is based on PFS or overall response rate, can be upgraded by 1 point if there is an improvement in QoL (form 3).

ESMO-MCBS version 1.1 instructions on scoring QoL benefit are limited to the requirements that QoL should be a primary endpoint (form 2c) or secondary endpoint (forms 2a, 2b, and 3), that a validated scale should be used, and that the gain must be statistically significant.

Given the importance of QoL for the final ESMO-MCBS score, a need to ensure the reliability and validity of the QoL data was recognized. This article describes the development of a checklist to guarantee that QoL data meet adequate methodological and reporting standards to justify an impact on ESMO-MCBS scoring.