The poor man's diseases
Via AdamSmithee, an article in Reason by Ronald Bailey praising for-profit pharmaceutical companies for their efforts in combating infectious diseases, even those of the poor. He tries to deflect criticism that less than 10% of global health R&D is spent on 90% of the world's diseases, and argues that, actually, most diseases affecting the poor already have effective treatments and it is poverty per se, and hence inability to afford medicine, that causes disease, rather than the selfishness of Big Pharma.
First, a point about river blindness (onchocerciasis): Bailey points out that the drug for river blindness was developed by Merck and is now being given away for free. He neglects to mention that the drug was actually originally developed to treat parasitic infections in horses, because treating horses owned by rich people is more profitable than treating poor people. This isn't exactly a bad thing - in fact, it shows how even the profit motive can produce serendipitous results. But it's not exactly a guaranteed way of discovering future medicines to treat diseases of the poor. And Merck isn't donating the medicine merely out of good will, but rather because the poor people who need couldn't afford to pay anything anyway. Most of the costs of drugs go into R&D, not actual drug production - since Merck already had this drug lying around that was originally designed for horses, they figured they might as well give it away and gain the good publicity. Again, not a bad thing - but also not a reliable way to generate more drugs. Certainly not reliable in the way that the profit motive will generate drugs for rich people's diseases. (Viagra, anyone?)
Meanwhile, the attack on the 10/90 claim is a strawman. It's certainly true that HIV, TB, malaria, and diarrheal diseases are generally the biggest killers of the poor (so in terms of sheer lethality, the "90%" of diseases receiving only 10% of global R&D aren't that bad). But the 10/90 claim is just a rallying cry, shorthand for the inequity of global health system. Taking the real killers: Leishmaniasis, malaria, trypanosomiasis and tuberculosis account for 5% of global disease burden (in terms of Disability-Adjusted Life Years, or DALYs) and certainly more of the disease burden in poor countires; yet they receive only 0.5% of global health R&D. Bailey himself admits that leishmaniasis and trypanosomiasis (sleeping sickness) still lack effective treatments.
Furthermore, Bailey overstates the extent to which the big killers have "effective methods of treatment and prevention." Let's leave aside the ridiculous implication that there's no need for drugs if a disease is easily prevented (imagine telling a heart attack patient, "no need for bypass surgery! you could have prevented this with a healthier diet"). Though malaria and tuberculosis have effective treatments that just need enough resources and public health infrastructure to be put into practice (a pretty big hurdle in many places!), the microbes will always be evolving resistance. Multidrug-resistant tuberculosis is already a problem, and it's only a matter of time before malaria becomes resistant to the last "ultimate" treatment, arteminisin combination therapy. Meanwhile, HIV is completely incurable, and antiretroviral drugs are expensive because of the profit motive. Some companies have started selling antiretrovirals more cheaply in poor countries, which is great; but we should have more of that. Plus, because it mutates so rapidly, HIV exists in multiple strains all around the world. The West is mostly affected by HIV-1 strain B, but the Third World has myriads of other strains - A, C, D, and CRF02 in Africa; B, C, and CRF01 in Asia. And these may not necessarily be as susceptible to treatments or vaccines being developed in the West as strain B.
In the end, Bailey is partly right in saying that the ultimate cause of all this unnecessary suffering is poverty. But diseases also cause poverty, and we can't overcome the vicious circle without a serious attempt to address the Third World's diseases. The Gates Foundation and the Global Fund to Fight AIDS, TB and Malaria are welcome funders in that fight. And we need not heavily tax drug company profits or destroy their patent rights (another strawman); we can, for example, guarantee that Fund X will buy a certain amount of drug Y if a company develops it, and thus provide an incentive to research and treat the diseases of poverty.