More info on Merck's Upcoming Hepatitis C Drug...

[Hep Editors]

FYI: Merck’s fixed-dose hepatitis C combination tablet, grazoprevir/elbasvir, has now received two “breakthrough therapy” designations from the FDA.

The nods are for the treatment of those with genotype 4 of the virus as well as people with genotype 1 who have end-stage kidney disease and are on dialysis.

For more info, click here: http://www.hepmag.com/articles/2501_27074.shtml

[dragonslayer]

Why would it be approved for Genotype 1 only if the patient is on Dialysis?  I mean, there are loads of serious life threatening conditions which are comorbid with HCV gt1; why would Kidney failure be the only gt1 co-morbid condition to qualify?

[Mike]

Some of the new treatments can be rough on the kidney's, especially if you are on dialysis Drinking massive amounts of water to cure side effects may also be a factor.

Thus the FDA fast tracked this protocol ".. to treat a serious or life-threatening disease or condition when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints.

Mike

[dragonslayer]

Some of the new treatments can be rough on the kidney's, especially if you are on dialysis Drinking massive amounts of water to cure side effects may also be a factor.

Thus the FDA fast tracked this protocol ".. to treat a serious or life-threatening disease or condition when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints.

Mike

I guess Im still not understanding.  If the Merck treatment is effective with genotype 1, then why would it only be approved for gt1 patients with kidney disease?  Why wouldnt serious liver damage in itself be enough to qualify?  Or any of the other myriad life threatening comorbid conditions?   I guess Im asking, what's special about kidney failure which places it above all the other life threatening conditions that a cure would alleviate?

[Mike]

The FDA gave it “breakthrough therapy” designation for these two groups. This means it can be prescribed now for these groups. It may for well receive approval across the HCV spectrum - but not at this time - as it's full efficacy needs more study.

It's kind of like a new cancer drug that is in clinical trials, and it is noted that, during the trials, the drug really works well on end stage prostate cancer - but needs further research regarding efficacy for skin cancer. It wouldn't make sense to deny the drug for prostate cancer - because further research is needed for to confirm the drugs effectiveness on skin cancer.

Mike

[dragonslayer]

The FDA gave it “breakthrough therapy” designation for these two groups. This means it can be prescribed now for these groups. It may for well receive approval across the HCV spectrum - but not at this time - as it's full efficacy needs more study.

It's kind of like a new cancer drug that is in clinical trials, and it is noted that, during the trials, the drug really works well on end stage prostate cancer - but needs further research regarding efficacy for skin cancer. It wouldn't make sense to deny the drug for prostate cancer - because further research is needed for to confirm the drugs effectiveness on skin cancer.

Mike

Right.. But in your example, it's been proven to work on one type of cancer, but needs further research for other types before they would approve or fast track it.. In the case at hand, it must have been proven to work for gt1 patients otherwise it wouldnt have been fast tracked.. It doesnt make sense that it would have shown to be effective only for gt1 patients that have end stage kidney disease, so Im wondering how they chose to limit it to them.. Why not fast track it for gt1 patients with symptomatic cirrhosis? Is their condition any less dire than gt1 dialysis patients?    Not to beat a dead horse, but Im not seeing the distinction.

[Mike]

The distinction is that, preliminary research indicates this drug works well for GT 1a's with advanced kidney disease and GT 4. There are other, effective drugs which have been vetted (completed FDA mandated clinical trials) that are on the market and work well (90%+ cure rates) for GT 1a who don't have kidney disease.

Mike

[dragonslayer]

The distinction is that, preliminary research indicates this drug works well for GT 1a's with advanced kidney disease and GT 4. There are other, effective drugs which have been vetted (completed FDA mandated clinical trials) that are on the market and work well (90%+ cure rates) for GT 1a who don't have kidney disease.

Mike

Got it.. Interesting that they should have stumbled across this correlation between gt1 and kidney disease such that it earns a fastrack.   Thanks for staying with me on the explanation.

[Mike]

Yes. It's very interesting. I'd imagine that the kidney patients were allowed in the clinical trials as a subset of GT 1a.

Basically, if you're on dialysis, you need a kidney transplant, which is the easiest organ to harvest & transplant - but the hardest to get.

If a co-morbid can be knocked out with a semblance of safety - it might push the person further up the transplant list.

I know everyone wants to bitch about big pharma (myself included); but thank be to God they are doing this type of research!

Mike