I see how it can be taken that way. Just not sure

I see how it can be taken that way. Just not sure that is the meaning..."kevetrin/sunitib combo is the 1st we've used in which actual tumor shrinkage is noted".

So - you think they're giving blanket statement that this is the first drug combo they have ever used that shrinks renal tumors?

PRs can be word-tricky. I think they might just be referring to this specific combo and the plural is referencing other kevetrin/multikin combos to come.