eldavojohn writes "Doctors Without Borders is reporting that four patents for tenofovir disoproxil fumarate, a key AIDS/HIV drug, have been revoked on grounds of prior art. This is potentially good news for India & Brazil who need this drug to be cheap; if the US action leads to the patent being rejected in these countries, competition could drastically lower prices. But the ruling bad news for Gilead Sciences. The company has vowed to appeal. We discussed this drug before."