Selzentry is the first new class of oral HIV medicines to be introduced in more than 10 years, Pfizer said at an annual medical conference in Chicago.
After a 48-week trial, nearly three times as many patients receiving the drug combined with traditional medication recorded undetectable levels of HIV virus, compared with those just getting the normal treatments.
"The safety and durability of response seen with Selzentry ... in our study is reassuring. This drug is an important new weapon for clinicians who treat HIV," said Jacob Lalezari, director of Quest Clinical Research, at the University of California.
The US Food and Drug Administration in August approved the use of Selzentry, which is the first in a class of drugs called CCR5 antagonists. They prevent the virus from entering the body's T-cells, rather than fighting the virus once it is already infected the cells.
The drug does not however cure HIV infection or prevent it from being passed to another person, the company warned.
The side-effects are similar to those experienced with other anti-AIDS drugs, including nausea, fatigue, headaches and diarrhea.
Experts believe the eventual sales of the drug could generate 500 million dollars for Pfizer annually by 2011. The company is also seeking permission for worldwide sales.
"Selzentry is the first in a class of drugs known as CCR5 antagonists, which block the CCR5 co-receptor, the virus? predominant entry route into T-cells," Pfizer said in a statement.
The drug "stops the R5 virus on the outside surface of the cells before it enters, rather than fighting the virus inside as do all other classes of oral HIV medicines."