My brother has been taking the Pegasy shots for a year now. They tell us that he is down to zero viral load but would like him to stay on the program for another 6 months because he wasn't down to zero in the first 6 weeks. Do you agree in this?

When treating a patient, we can estimate the duration of treatment based on genotype. For example, genotype 1 is usually treated for 48 weeks and genotype 2 or 3 is treated for 24 weeks.

I suspect that his physician is looking at your brother's viral load response and calculating a certain amount of time after that to ensure that his virus doesn't come back after treatment is stopped.

Tailoring a patient's treatment duration is a rather new concept that has evolved over the past year or two. A rapid viral load response is defined as no detectable virus at four weeks. When this is not achieved, we also look at responses at 12 weeks to be certain that the patient has finally declined to no detectable virus.

When a patient does not clear virus completely by 12 weeks, I do tend to treat longer - and usually give 36 more weeks of treatment once the patient has achieved a non-detectable viral load. I give 36 more weeks based on a meta-analysis by Drusano and colleagues. If the patient still has virus at 24 weeks, I stop therapy.

I hope this is helpful.