Only days after news of the failure of a major Merck HIV vaccine research trial, rival pharmaceutical company Pfizer Inc. has announced the European Commission (EC) approval of the company’s AIDS drug, Celsentri, known generically as maraviroc. The drug is the first in a new class of oral HIV medicines in more than a decade.

Maraviroc, discovered and developed by Pfizer in Sandwich, Kent, blocks viral entry of the HIV virus into white blood cells.

The drug will be available to treatment-experienced HIV patients in the EU in combination with other antiretroviral medications.

Rather than fighting HIV inside white blood cells, maraviroc prevents the virus from entering white blood cells by blocking its predominant entry route, the CCR5 co-receptor, according to a press statement from Pfizer.

“HIV is a significant health concern in Europe and infection rates are still increasing.

“Without new medicines, resistance to current treatments is one of the biggest challenges facing HIV care today,” said Filippo von Schloesser, president of Italian HIV patient organisation, Fondazione Nadir Onlus, in the Pfizer press release.

“The approval of maraviroc will offer a new option to many people living with HIV in Europe.”

The EC approval of maraviroc is based on 48-week data from the two ongoing double-blind, placebo-controlled clinical trials.

Data from the trials show that the drug, in combination with optimised background therapy (OBT) provides substantially greater viral load reduction compared to OBT therapy alone.

In addition, more than twice as many patients receiving maraviroc and OBT in combination achieved an undetectable viral load compared to OBT alone.

“Maraviroc is an important additional treatment option for R5 tropic treatment-experienced patients in Europe,” said Gerd Faetkenheuer, MD, Department of Internal Medicine, University of Cologne, Germany.

“Although other treatments are currently available, maraviroc targets the fight against the HIV virus in a new way.”

Maraviroc, known as Selzentry in the United States, was approved by the U.S. Food and Drug Administration (FDA) on August 6, 2007 and is currently available in the U.S.

Industry analysts have projected annual Celsentri sales of about $500 million by 2011, according to a Reuters report.

Laura Vess © 2007 GayWired.com; All Rights Reserved