Drano, I agree that the primary objective is safety. But efficacy is the secondary objective, that's why p21 is measured every 7th and 24th hour. Kevetrin is already established as very tolerable at the lowest dosage after the first cycle, and since the ultimate goal is to find the maximum tolerated dosage, why repeating the cycles numerous times at the lowest dosage level if no benefits were observed? I think we just have different interpretations of Andrew's words: "perceive a benefit (stable disease or improvement)".

FWIW DrFeelgood said the starting dose was unusually high for cancer drugs. That's why efficacy might be observed.