August 4, 2009

August 4, 2009
Suitability for CCR5 treatment

Thanks for joining me for another day in my life. Today is Tuesday and I hope you are having a safe and great week so far.

I got off to a rough start this morning. From the moment I woke up I could tell something was not right. I was in pain from my waist down with a majority of the pain in my legs. Luckily, I already had a scheduled with my doctor today. So after meeting with Dr. Portalatin, we concluded the disks in my back are continuing to degenerate. Now whether the degeneration is caused by age, HIV medications or the virus really does not matter when you are in pain. So my doctor is going to order some more tests and we will see what the outcome is when I go in a few weeks for my next visit.

But what I would like to talk about today is suitability for CCR5 treatment.

Genotypic tests are just as accurate as tropism testing at showing which individuals are suitable for treatment with CCR5 inhibitors.

Furthermore, a reanalysis of results from a clinical trial using sensitive tropism testing has shown that maraviroc is as good as efavirenz, and even has some advantages over the current standard of care.

CCR5 inhibitors can be an important option for treatment-experienced patients. However, they only work if a patientís HIV uses the CCR5 coreceptor to gain entry to CD4 cells. Maraviroc (Celsentri) is the only CCR5 inhibitor currently licensed, but others are in development.

Canadian researchers used stored blood samples from 1216 patients who participated in trials into maravirocís development. They found that genotypic and tropism testing after 8 and 24 weeks of treatment were equally accurate at predicting who would respond to treatment with the drug.

A major advantage of genotypic testing is that it is much cheaper than tropism testing.

A separate paper presented to the conference has shown that antiretroviral therapy based on maraviroc is just as effective as treatment containing efavirenz (Sustiva or Stocrin) at suppressing viral load to undetectable levels. Furthermore, patients treated with maraviroc had better increases in their CD4 cell count and lower rises in cholesterol.

Pfizer, who make maraviroc, conducted a reanalysis of the 96 week data from the MERIT study using a more sensitive tropism test. This test accurately predicted who would benefit from maraviroc therapy. When the results of this enhanced test were used the researchers found that equal proportions of patients taking maraviroc and efavirenz had an undetectable viral load after 96 weeks.

This reanalysis is likely to provide sufficient evidence to justify the licensing of maraviroc for use by patients starting HIV treatment.

Those are my thoughts. Drop me a line and let me know what you think.

Wishing you health, hope and happiness.

big bear hug,

Daddy Dab