"I thought KN-426 would be great, but damn .53 HR! I would guess that if you ran this trial 100 times this .53 HR would be in top 5% upper tier of best possible outcomes. Yeah, I think KN-426 got some favorable statistical randomness. I would be shocked if this HR improved on subsequent analysis..."
First, I doubt that there will be continued follow up for more mature data. They already hit on all the primary and secondary endpoints, there is nothing left to prove. Hypothetically, if there were follow up, and HR=.53 is a favorable outlier, you would have two competing forces, you may get a reversion to the norm pushing toward a less spectacular outcome, but remember checkpoint survival vs TKI monotherapy improves with time. That fat tail on the right side of the survival curve pads the HR advantage. No matter how you cut it, it is a very tough act to follow.
Keep in mind though, until something better comes along, Cabo will still be the preferred 2L treatment for patients who progress on Pembro/Ax.