For the first time, he has a wide range of choices of HIV therapies, all with the potential to significantly prolong life. The problem now is finding out which drugs, or combinations, are best to combat HIV, the virus that causes AIDS.

Finding the answers will not only mean longer life for HIV patients. It could also mean billions of dollars in revenues for pharmaceutical manufacturers who, for the first time, can treat the human immunodeficiency virus as a chronic condition that requires patients to take medications over the course of a normal lifespan.

With about a dozen drugs available, either approved or in clinical trials, researchers have learned that combinations of drugs are more effective at attacking the virus than any one drug by itself. Recent clinical trials show some combinations hit the virus so hard that it is undetectable in the blood.