What? Really? This argument is something I would expect someone like Josef Mengele to say, not a modern human being in the 21st century.
You can't just leave ethics out of science. Doing so would pave the way for so many atrocities against both humans and animals "in the name of science" (and history is evidence of this).
If the experiments on monkeys would lead to a medicine that would improve life of millions, would you still ban it "for the sake of humanity"? Ethics sure have its place, but it must not hinder the vital progress. Today you save monkey from being "treated unethically", tomorrow you die with the same monkey from unstudied disease.
You can't just leave ethics out of science. Doing so would pave the way for so many atrocities against both humans and animals "in the name of science" (and history is evidence of this).