TOPIC: 8 weeks versus 12 weeks Harvoni

For patients who are all of

• GT1
• Treatment naive
• No cirrhosis
• Taking Harvoni
• Viral load < 6,000,000

The guidelines suggest 8 weeks treatment is ok. But is it really?

In this VA study of 4,365 patients they concluded:

Conclusions: In this real-world cohort, SVR rateswith LDV/SOF6RBV nearly matched the rates reported in clinical trials and were consistently high across all sub-groups; those without cirrhosis but with HCV RNA<6,000,000 IU/mL were less likely to achieve SVR with 8 weeks compared to 12 weeks of therapy, although the numeric difference in SVR rates was small.

www.researchgate.net/publication/3016714..._C_Infected_Patients

Hmm, small. What's small?

Small is 96.6% SVR at 12 weeks compared to 93.2% at 8 weeks.

Putting that in failure terms:

3.4% failure at 12 weeks compared to 6.8% failure at 8 weeks.

So if you fit the criteria, and only do 8 weeks you have DOUBLE the failure rate.

DOUBLE is not small to me. Double is big.

I don't know about you, but I would be wanting that extra 3.4%

Also note this. The same study shows (as did we with generics) that patients who are detectable at the 4 week test (that's detectable at all and includes <15 detected) are 2.5 times more likely to fail, compared to patients who are undetected at this point.

So the only reason that I personally would do only 8 weeks would be if that was all I could get. If I was still detected at the 4 week mark I would be very nervous.

If you are female, if you have low fibrosis, if you are undetected at 4 weeks these are all good, but still - DOUBLE THE FAILURE RATE

Double is not small.

Unlike fertilizer, more is better.
No place to cut corners here.
Go the 12 week route.
m

In my case <15 was undetected. The doctor told me that <15 detected was not what I wanted, but since mine was undetected he had it that I would most likely not relapse.
So again "undecided <15" is good if your laboratory can only go down to <15. But if you have "<15 decteded", yes this is reason to start thinking retreat.

Dr Freeman if this is so why don't they develop better testing to go all the way to zero undetected? The labs here in the US mostly are <15, undetected or detected, why?

.
HCV RNA consists of 9600 bases. Each weighs about 650 Daltons and 1 Dalton is 1.67 x 10^-24grams so you could multiply all those together and get a really small number - about 10^-17 grams.

That's really really really really really really really really really really really really really really really really really small.

0.00000000000000001 g

We use the process PCR - which is Polymerase Chain Reaction like this. We add some blood that may have RNA in it to a chemical soup of RNA duplicators. We incubate it to make lots of RNA, and only now do we have enough to count.

So that is problem 1.

Problem 2 is that it only takes about 10 Hep C virions (viuses) to cause infection.

If these were all in your blood, and there were only 10, and you have 5 litres of blood (you do) then we would need to draw off 500 ml to have a chance of getting 1 virus. We only take 5 ml.

And of course most of the HCV is NOT in your blood - it is in liver and other cells.

So while it would be great to measure down to zero it is fundamentally impossible to do so because:

1. We can't measure small enough
2. We can't take enough blood, you would die
3. And there is more virus not in the blood that we simply can't get at - we would have to homogenise at least 10% of you in a blender per test

Take 12 weeks!
m

What he said!

in my case I chose 12 weeks ( had to..... ), however I would not put my bet on the 8 weeks.

Go for 12 weeks, it's such a small price to pay for a big advantage

My doc said "your good to go for 8 weeks". Then he said "if you can get 12 weeks do it"
I did 12 and did not look back, glad I did. Even if VL is low, under 6,000,000, go 12 weeks to be sure.
And what Mike G and Dr F said!