Idenix Pharmaceuticals (IDIX)

[gofishmarko]

" Switching Therapy From Lamivudine to Telbivudine Versus Continued Lamivudine in Adults With Chronic Hepatitis B "

How would this study change my thinking ? The question was one of whether telbivudine is superior to adefovir in lam-resistant patients. Only a head-to-head trial will demonstrate that.

I think telbivudine will get some usage here , I just don't think there's anything to suggest it will supplant adefovir , or entecavir for that matter. If a lam-resistant patient is screened for resistance mutations and found to be free of the rtM204I variant that confers resistance to telbivudine , then that patient might be expected to do as well , or better , than if placed on adefovir or entecavir. Alternatively , I'm sure that often a patient is simply switched and followed closely to make sure they're responding. However , a doc can simply switch that same patient directly to adefovir or entecavir and know with near certainty that there will be viral suppression for some time. That's the hurdle telbivudine has to overcome with their studies.

The treatment that makes more sense than any switch to monotherapy using current drugs is simply adding adefovir to lamivudine in lam-resistant patients , since lam is relatively cheap. This way you get the complimentary resistance profiles .

Resistance profiles are not the only factor , of course. Antiviral potency is important too , since resistance mutation frequency is a function of viral load , and antiviral potency is where telbivudine shines. I just think they'll have to demonstrate comparable or superior performance to current drugs before docs make wholesale changes in treatment strategy.