I don't really see it as philanthropic but just part of society building. We establish medical care and labor laws and etc to prevent easily preventable deaths, and so the same sort works when it comes to treating tropical diseases. In this instance, its those outside a certain nation (most of the developed world has already eradicated malaria) which I feel is probably a net positive for all of us. It most likely is going to enhance things like productivity and output in nations that still deal with these diseases, and I could imagine plenty of scenarios where it makes sense to help fight diseases, looking at things beyond an ethical sense.

Malaria at the moment can be treated with prescription drugs, but the emphasis right now is on eradication is on ending transmission. I think it would be more costly to send medicines than things like bed nets and DDT, and I don't think it would be as effective. The goal is to wipe out the habitats that house malaria.