Form 1 of the European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) serves to grade therapies with curative intent. Form 1 provided very reasonable grading and expert field testers confirmed the reasonableness of generated scores. Exploratory toxicity evaluation and annotation was feasible but problematic given inconsistent toxicity reporting and limited results of late toxicity. Moreover, the experts identified the inability of crediting improved convenience in non-inferiority trials as a shortcoming. Future revisions of Form 1 of the ESMO-MCBS will be cognoscente of these findings. Read the paper on the ESMO Open website: http://dx.doi.org/10.1136/esmoopen-2020-000681