Biotech Values

[gofishmarko]

HCV and future combos

The reason I found the VRTX 8-patient results so compelling is that it fits into what strikes me as a rational treatment approach i.e. drive viral load to undetectable levels (or nearly so ) then follow with a regimen that generates an effective immune response to mop up the last vestiges or suppress them indefinitely , whichever may be the case.

No drug alone or in combo has shown an ability to rapidly sterlize a patient r.e. HCV , probably because there are always some drug-inaccessible reservoirs of virus or there are resting , but replication-competent virions that are not susceptible in the resting state. VX950 plus pegifn rapidly decreases viral load, probably mostly through direct antiviral means or a combination with innate immune mechanisms. IMO , the follow-on with pegifn plus riba mainly functions to redirect the adaptive immune response (while maintaining viral suppression by mixed mechanisms ,probably).

The ANDS and COLY candidates would be expected to compete with the ifn/riba combo , while it's easy to imagine a PI and a polymerase inhibitor ( or other combos ) as the future treatment for the first phase. Some patients may not need the immune treatment phase after viral load has been supressed for a sufficient length of time , but many, if not most, will , I believe , as the virus-induced immune tolerance persists.

I agree with Thomas that there is a limit to the number of drugs in any combo treatment , mainly imposed by cost concerns. The population most likely to have HCV is also the population least likely to have insurance or the means to pay. Of course , a regimen that reduces treatment time from 48 weeks to 10 or 20 weeks, or less , would allow more drugs to be used without driving up the cost so much.