Pharmaprojects R&D Pipeline News Feed
World AIDS Day offers chance to reflect on recent therapeutic advances
30 Nov 2007
December 1st marks the 20th anniversary of World AIDS Day. Twenty years ago, the WHO established World AIDS Day in order to raise awareness and focus attention on the global AIDS epidemic. AIDS, or acquired immunodefficiency syndrome, is a result of infection by the human immunodeficiency virus (HIV). Over time, the virus weakens the immune system to such a point that opportunistic infections or cancers that it would normally deal are able take hold. It is these infections and malignancies that are the ultimate cause of fatalities in AIDS patients. It is estimated that 33.2 million people worldwide are living with HIV, with more than 73,000 of those in the UK. In 2007 there were 2.1 million HIV-related deaths. With this number increasing each year, it is evident that there is a growing need to get this epidemic under control.
Since the last World AIDS Day there has been a couple of significant additions to the anti-HIV drug armoury, firstly with the news in October from Pfizer that it has launched its first-in-class treatment maraviroc (Celsentri) in the UK and the US. Maraviroc inhibits the chemokine receptor 5 and so acts as an HIV co-receptor entry inhibitor; as such, it is only indicated for use in patients infected with CCR5-tropic HIV-1. Pfizer has now initiated an expanded access programme in 30 countries to make maraviroc available to patients who have limited treatment options due to resistance or intolerance. Another CCR5 inhibitor in the pipeline, Schering-Plough's vicriviroc maleate, entered Phase III trials in September this year.
Secondly, another first in class therapy, Merck & Co's raltegravir (Isentress), was then launched just one week later. Raltegravir is an HIV integrase inhibitor, preventing thre virus from integrating its genetic material into the host cell. In Phase III trials with raltegravir, 24 week results showed that 75.5 and 62.6% of patients on raltegravir achieved a viral RNA load <400 and <50 copies/ml, respectively, compared to 39.3 and 33.3%, respectively, for patients on optimized background therapy alone.
These novel treatments for AIDS/HIV are a great achievement for the pharmaceutical companies involved and great news for the patients themselves, at least in the developed world where they can afford them. They may also provide some respite from the cumulative toxicities of current anti-HIV drugs. With the ongoing work from both the pharmaceuticals companies and the many charities and non-profit organisations that have also taken up the cause, perhaps the dream of affordable and effective treatments for AIDS sufferers around the world will be soon be realized.
