[evandijk70]

Based on the abstract of the article https://www.nejm.org/doi/full/10.1056/NEJMoa2304594?query=fe...,

I actually think the other explanations are wrong. They are probably reporting the Hazard Ratio, which is more often used as primary outcome for efficacy of drug than 5 year survival. (See for example: https://en.wikipedia.org/wiki/Hazard_ratio)

The hazard ratio, under some assumptions, tries to estimate the relative risk of dying per unit of time. The benefit of this measure is that there is not some artificial cutoff (the difference between a death at 4 years and 364 days and 5 years and 1 day is neglible).