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What is the risk of cancer in humans, if any, with Valcyte?

Sasha

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Are there any stats on this? A swift google shows me that Valcyte has caused tumours in animals but I can't see any data on humans.

Any studies?
 
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37
I've read it somewhere.. can't find the article now. The dose which was used was VERY VERY high.. and over a long period of time (i think 2 years?) Calculated on a human, you never ever would take such huge doses (i think they talked about 6000mg daily, im not sure).. 2 years on 13 valcyte tablets a day..... normal therapeutical dose is 2 tablets a day.

Furthermore someone here said, that the animals developed cancer in areas, which doesnt exist in humans.

People with transplanted organs HAVE TO take Valcyte 6-12 months.. i think if the risk of cancer would be that high, no one would take it.. no doc would give it to you
 

Sasha

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UK
I've read it somewhere.. can't find the article now. The dose which was used was VERY VERY high.. and over a long period of time (i think 2 years?) Calculated on a human, you never ever would take such huge doses (i think they talked about 6000mg daily, im not sure).. 2 years on 13 valcyte tablets a day..... normal therapeutical dose is 2 tablets a day.

Furthermore someone here said, that the animals developed cancer in areas, which doesnt exist in humans.

People with transplanted organs HAVE TO take Valcyte 6-12 months.. i think if the risk of cancer would be that high, no one would take it.. no doc would give it to you

Thanks copi2k - that's interesting.

I need some references - my doctor doesn't want me to go on Valcyte, partly because of the cancer risk and I need to go to my next appointment armed with journal articles or whatever hard info there is. I'd be really grateful if someone could point me at something.

In the meantime, that's interesting about the animals (I'm wondering what bits they've got that we don't!) and the transplant patients. You'd think there'd be some data on transplant patients.
 

heapsreal

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Thanks copi2k - that's interesting.

I need some references - my doctor doesn't want me to go on Valcyte, partly because of the cancer risk and I need to go to my next appointment armed with journal articles or whatever hard info there is. I'd be really grateful if someone could point me at something.

In the meantime, that's interesting about the animals (I'm wondering what bits they've got that we don't!) and the transplant patients. You'd think there'd be some data on transplant patients.

it sounds more like an excuse for your doc not to prescribe it, maybe just doesnt understand valcyte well as not many docs have probably ever prescribed it. Sounds like an arse covering exercise from your doc but could be wrong. I would maybe consider finding another doc to prescribe it and who will work with your current doc if he is good for other treatments etc

good luck with it.
 

Sasha

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UK
it sounds more like an excuse for your doc not to prescribe it, maybe just doesnt understand valcyte well as not many docs have probably ever prescribed it. Sounds like an arse covering exercise from your doc but could be wrong. I would maybe consider finding another doc to prescribe it and who will work with your current doc if he is good for other treatments etc

good luck with it.

Hi heaps - I live in the UK and am within the NHS system. It's my GP who doesn't want to risk it but he's referred me on to an infectious diseases consultant who might, if I can go armed with the facts. It's the nature of the system here - if you request something that isn't usual for the NHS (and the treatment of high HHV-6 titres with Valcyte for people who don't have HIV or have had an organ transplant or similar) you've got no chance of getting it unless you go in with all the facts. There's a limit to how many specialist referrals I can get before my GP will stop sending me. My GP does his best within the limits of the system - getting another GP will just get me another one dealing with the same system.

A long way of saying that I need the scientific literature about the cancer risk. I'd also like the info for myself, let alone my doctor! :)
 

heapsreal

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Hi heaps - I live in the UK and am within the NHS system. It's my GP who doesn't want to risk it but he's referred me on to an infectious diseases consultant who might, if I can go armed with the facts. It's the nature of the system here - if you request something that isn't usual for the NHS (and the treatment of high HHV-6 titres with Valcyte for people who don't have HIV or have had an organ transplant or similar) you've got no chance of getting it unless you go in with all the facts. There's a limit to how many specialist referrals I can get before my GP will stop sending me. My GP does his best within the limits of the system - getting another GP will just get me another one dealing with the same system.

A long way of saying that I need the scientific literature about the cancer risk. I'd also like the info for myself, let alone my doctor! :)
understand how hard it is there. Any chance of crossing the pond to see a doc?
 

golden

Senior Member
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1,831
Could you ask your G.P for the links to the studies he refers to?

Could the manufacturers of the drug offer insights?
 

Sasha

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Hi golden - those are good ideas.

I was hoping someone on here might know, though! :)
 

vamah

Senior Member
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593
Location
Washington , DC area
I have to agree that the cancer in animals rationale just sounds like an excuse not to prescribe. Probably because Valcyte is very, very expensive. I couldn't find info on what the cancer risk was in animals either. I'm not sure what you can do about that, if that is what your GP wants. One tactic would be to be able to cite for him some drugs routinely prescribed by the NHS that also carry health risks (almost all drugs do) and then compare to Valcyte risks. Theoretical cancer risk aside, it is a very "safe" drug. The most common serious side effect is anemia, which can be caught and reversed as long as you get regular blood tests while taking it. One other idea would be for you to try to contact Dr. Montoya at Stanford Univeristy, who is the expert on treating HHV-6 with valcyte. I know someone who has been in contact with him and that he is very responsive and sympathetic. He might be able to provide you with the information you need about cancer risk, etc.
 

golden

Senior Member
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1,831
Sorry Sasha , I see :)

Animal Studies are useless and pointless and the fact that Valcyte causes cancer in animals means nothing for humans.

The links suggest it is unknown if Valcyte causes cancer in humans so the experiment on humans is currently underway.

When they receive enough deaths from cancer in humans - they will remove the drug from the market or put warnings on packages and so on.

http://www.pdrhealth.com/drugs/valcyte

It sounds like a nasty drug to me. I took Ro-accutane many years ago and deeply regretted it.

I would definitely ask G.P. where he is getting his info from because he may actually be reporting the doctors inner circle advice to you rather than trying to stop you from getting an expensive drug.
 

Sasha

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UK
I don't know that this is helpful:

http://www.medicalnewstoday.com/releases/8455.php

Ganciclovir (Valcyte(reg)/Cymevene(reg)) reduces risk of cancer in kidney transplant patients

Interesting - this is my concern, that HHV-6 in the long term might predispose me to cancer (I don't think that that's established but it's a worry since CMV, another HHV, does so) so leaving it untreated is worse than taking a drug with a cancer risk.
 

Sasha

Fine, thank you
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17,863
Location
UK
I've just read this on another thread, posted by charityfundraiser:


Hope123 said: If I remember right, the cancer risk related to Valcyte was from studies in mice who took higher doses and the cancer developed in tissues that did not have an analagous component in humans.
I remember Dr. Montoya saying something to that effect and similar rumors on message boards. The actual drug information sheet says both of those statements are false. Yet another thing I have realized only later harmful about his treatment and interaction with patients. Also receiving the same dosage as patients twice my weight (the average American).​
"Toxicity in mice, dogs and rats was primarily characterised by testicular atrophy. Male infertility occurred at doses of 2 mg/kg/day and above which was consistent with the infertility and testicular atrophy seen in toxicity studies with doses between 2 and 10 mg/kg/day. In females, a more complex range of effects were induced which were characterised by embryo-foetal abnormalities and embryo-foetal losses in mice and rabbits and in multi-dose studies, by toxic and eventually carcinogenic changes to the reproductive system in mice.​
Ganciclovir was carcinogenic in the mouse after oral doses of 20 mg/kg/day for 18 months and 1000 mg/kg/day for 15 months. All ganciclovir-induced tumours were of haematopoietic epithelial or vascular origin. Epithelial tumours involved a wide variety of tissues, including the female reproductive organs, pancreas, gastrointestinal tract and skin, as well as rodent specific glands (perputial, clitoral and Harderian). Vascular tumours were observed in females, mainly in the reproductive organs, but also in the mesenteric lymph nodes and liver. No carcinogenic effects occurred at 1 mg/kg/day. Based on data on plasma drug concentrations, exposure of humans to ganciclovir would be similar to or greater than the exposure of mice in the above study at 1000 mg/kg/day. This potential is likely to be markedly greater in children, as cell division occurs more rapidly in children."​

I've seen it said elsewhere that animal models aren't informative for humans but I'm not sure I find that plausible as a blanket statement. I can't find any study data on which this Roche statement is based so can't drill down into the figures.

I only have a high IgG titre to HHV-6 (not positive by PCR) and am wondering how to weigh the cancer risk against what might or might not be a real HHV-6 reactivation.

How should I weigh up this information, both qualitatively and quantitatively? For example, I gather that long-term reactivation of herpes viruses is associated with cancer but I don't know the relative risks. What else should I be factoring into my decision?
 

heapsreal

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Low nk function can increase the risk of cancer. Some after treatment with antivirals have had improvement in nk function, some havent. I dont know if theres an answer, in general theres little know about hhv6 etc compared to other causes. As for nk function, its role is to kill viruses and cancer cells. I think all i have done is muddy the water for you.
 

Sasha

Fine, thank you
Messages
17,863
Location
UK
Low nk function can increase the risk of cancer. Some after treatment with antivirals have had improvement in nk function, some havent. I dont know if theres an answer, in general theres little know about hhv6 etc compared to other causes. As for nk function, its role is to kill viruses and cancer cells. I think all i have done is muddy the water for you.


Interesting. My NK cell function test was at the lower end of normal (just to add to the ambiguity).

I've heard people say that the US docs who have been using Valcyte for a long time haven't seen an increase in cancer in their patients but unless they're doing 10-year follow-ups, I'm not sure whether that's based on hard data.
 

Tristen

Senior Member
Messages
638
Location
Northern Ca. USA
Are there any stats on this? A swift google shows me that Valcyte has caused tumours in animals but I can't see any data on humans.

Any studies?

I believe Vistide has a much greater risk of Cancer than Valcyte. But hey, we are racing against time on that one anyhow. "Do the benefits outweigh the potential hazards. I developed throat cancer, but have been fortunate to have put it down with conventional Tx's. I remain clear 1 year post Tx. The cancer was likely not from the Vistide.....more likely the impaired immune system allowed the HPV to take off.