I am not in medicine or science so I have a question on...

I am not in medicine or science so I have a question on interpretation if you're able to consider in your writings. Given these patients were very sick and I note that the deaths of many patients was due to indirect reasons not the cancer e.g. sepsis, GvHD, how is the concept of a 'response' and a 'non response' specifically determined?

That is, do the high rates of infection, early death etc mask that the response rate among the 15 who survived to receive treatment (of the original 20) may have been even potentially higher 'but for' their deaths? Or is it safe to assume that the 9 who did not technically respond showed absolutely no indication that the drug had or would have any effect? I'm assuming that some of those 9 might never have responded given their specific cancer's resistance, but that others may have had a chance to response but died too rapidly after dosing to see a response recorded - and thus might technically be viewed as neutral toward efficacy.

(As an aside feels weird to write coldly about humans like this).