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Cancer-fighting viruses win approval

nature.com

140 points by pravka 10 years ago · 25 comments

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cryoshon 10 years ago

Definitely a really cool project! I have had the privilege to collaborate with an immuno-oncology group at Dana Farber a few years back, and they're perpetually on the top of their game, and at the edge of human knowledge. Based off of this article, there is a lot more work to be done, though:

"But statistics — not anecdotes — rule over drug approvals. In 2005, regulators in China approved an oncolytic adenovirus called H101 to treat head-and-neck cancer, after evidence showed that the treatment could shrink tumours. Those trials stopped short of assessing improvements in patient survival — a measure often required for FDA approval. Since then, a medical-tourism industry has built up in China for people who cannot get the therapy in their home countries.

Then, in May this year, a team supported by biotechnology giant Amgen of Thousand Oaks, California, published promising results from a large clinical trial of T-VEC (R. H. Andtbacka et al. J. Clin. Oncol. 33, 2780–2788; 2015). The virus both shrank tumours in people with advanced melanoma and extended patient survival by a median of 4.4 months. Yet statistically, survival benefits fell just a hair’s breadth of significance. “That raised the question, ‘Well, what is statistical significance? Is this an active agent or not?’” Russell says."

It's possible that a more immunogenic (eliciting immune response) virus would have better results against cancers. Of course, this means that it would also hurt the patient more. I'm sure they know this already.

Though I'm biased, I think that given the current state of viral engineering, immunotherapy (immune cell gene-engineering and transplantation)is a better way of getting at cancer for now-- it's rapidly being proven in the clinic and the lab. I can see a time 10 years from now where we'll be able to engineer certain viruses to be powerfully oncolytic, but for now I think the problems are specificity of targeting (you only want to kill tumor cells) and the inability for prototype oncolytic viruses to infiltrate the tumor microenvironment. The infiltration problem isn't a hard dead end, nor is it a problem unique to viral therapies, but a couple of the bleeding edge immunotherapies and even older radiotherapies and chemotherapies can pierce into the tumor microenvironment with no problem.

Though I expect immunotherapy to beat them to the punch, I can completely see oncolytic viruses joining the combination regimen that is the standard of care, alongside surgery, chemo and radiotherapy, provided that they show a more concrete improvement in survival rate/length.

mindcrime 10 years ago

Oncolytics Biotech is studying a virus that hitch-hikes through the body on certain blood cells, camouflaged from the immune system.

Is it just me, or does this sound kinda dangerous? That is, engineering a virus specifically to evade the immune system. As long as it stays un-mutated, fine. But what if a mutation occurs that results in it becoming a deadly disease, with the bonus of being "camouflaged from the immune system"?

  • ars 10 years ago

    > But what if a mutation occurs that results in it becoming a deadly disease

    It seems dangerous to me as well, but I should point out that viruses don't typically do that - they are either dangerous or not. They might change how infectious, or which species they target, but it rare to go from harmless to dangerous.

    It's also not in their interest to be dangerous, it's better for them to simply be infectious without causing serious illness.

  • maxerickson 10 years ago

    The virus was selected because it already evades the immune system:

    https://en.wikipedia.org/wiki/Talimogene_laherparepvec

    https://en.wikipedia.org/wiki/Herpesviridae#Immune_system_ev...

    They altered it to make it less virulent to normal cells and more lethal to cancer cells.

    • crpatino 10 years ago

      Your answer is not very reassuring on the mutation front.

      Considering that what you said can be translated to "we are curing cancer with an infectious disease that was modified to spread more slowly and kill cancer cells faster than it kills you", I don't think it is reassuring to the people that has to live day to day with the patient either.

      It is a horrible necessity to have cancer patients be dosed with poison, but infecting themselves with something that can get to their families is in another league.

      • maxerickson 10 years ago

        Spread more slowly is an understatement, a critical gene is deleted so that the virus cannot replicate in healthy cells. Also, it's a virus that causes cold sores. Not something you want your family to get for no reason, but not really horrifying either.

  • eliben 10 years ago

    Getting a herpes is probably a side effect folks with advanced melanoma could live with.

    • ars 10 years ago

      Is it contagious? Herpes is. In the scenario at hand the virus would transmit to others.

  • zamalek 10 years ago

    > Is it just me, or does this sound kinda dangerous?

    Dr. House is full of truisms and one pops up here. Doctors are also seriously concerned about the potential dangers of this treatment; however, they have determined that against the risks of cancer it's worth it.

    No medicine is risk-free. Medicine replaces an active condition with a chance for a less severe condition. Cold sores (if they even present as a side effect) have a much better prognosis than cancer.

  • jmeekr 10 years ago

    My thoughts exactly. Has no one studied the plot to I Am Legend?

jjbiotech 10 years ago

How can they prevent this virus from evolving to replicate in non-cancerous cells? I wonder if that's why they started with a benign virus like herpes.

Very cool, but slightly scarey at the same time.

Edmond 10 years ago

penny stock, is this a buying opportunity? I have previously had painful misses on early stuff like this.

bitwize 10 years ago

Fuck yeah, medical science. If ever a fight were worth cheering for, it's the fight against disease.

known 10 years ago

Prevention is BETTER than cure; Editing DNA can PREVENT Cancer; But Govt is NOT approving it;

suprgeek 10 years ago

Very good!

Kill the big dog by infecting the body with a smaller disease that is lethal to the big dog but (slightly) less lethal to the host.

So this can either go the "World war Z" way or the "I am legend" way - that's a cheery thought

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