The FDA has granted approval to Pfizer’s maraviroc HIV treatment, the drugmaker said today.

Maraviroc, to be marketed under the brand name Selzentry, is expected to be available in the US by the middle of September.

Maraviroc is the first in a class of drugs known as CCR5 antagonists, which works by blocking viral entry into white blood cells, significantly reducing viral load and increasing T-cell counts in treatment-experienced patients infected with a specific type of HIV.

Maraviroc was granted approval under priority review status, which trims time off the standard approval time period. Priority review is usually granted to compounds deemed an advance over existing therapies by the FDA.

Maraviroc hit a bump in the approval process when Pfizer received an approvable letter in June requesting additional information on the drug.
 
The FDA in April raised concerns that maraviroc could be associated with an increased risk of liver damage, lymphoma and infections.
 
According to FDA, other developmental CCR5 inhibitors have been shown to increase safety risk issues.

However, Pfizer said its studies showed that maraviroc had no significant effect on the heart and did not increase the incidence of liver problems, cancer or infection compared with other HIV/AIDS drugs.

Analysts have projected sales of maraviroc to reach $500 million by 2011.