Drawing the Hazard Ratios together from the Genentech/Roche...

Drawing the Hazard Ratios together from the Genentech/Roche registrational ToGA study and HER-Vaxx makes for an interesting comparison. The information is drawn from the announcements of 23 November 2020 and 1 September 2021. I tentatively make the following points from a layman's perspective understanding that clinical trial analysis is highly technical and its easy to get things wrong or confused.

Firstly, the progression free survival HR for ToGA was 0.71 while the overall survival HR for ToGA was 0.74.

Lets switch to HER-Vaxx: progression free survival HR of 0.719 and overall survival HR of 0.418. Now, we need to make the qualification that the final OS HR for HER-Vaxx could change because the original hazard ratio was based upon interim analysis. Note: its not inconceivable that the OS HR could change for the even-better-still dependent upon final results.

My simplistic understanding leads me to conclude that the PFS and OS hazard ratios in the ToGA study were somewhat aligned but in the HER-Vaxx study there is a major divergence. I understand that overall survival is the primary endpoint which is understandable given that for a patient with gastric cancer one presumably would want to live longer particularly if one could do so with quality of life and lower levels of adverse events.