Slashdot Mirror
Drug Turns Immune System Against All Tumor Types
sciencehabit writes, quoting an article in Science: "A single drug can shrink or cure human breast, ovary, colon, bladder, brain, liver, and prostate tumors that have been transplanted into mice, researchers have found. The treatment, an antibody that blocks a 'do not eat' signal normally displayed on tumor cells, coaxes the immune system to destroy the cancer cells."
The abstract and full paper are freely available. It seems fairly promising: "In mice given human bladder cancer tumors, for example, 10 of 10 untreated mice had cancer that spread to their lymph nodes. Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer. Moreover, the implanted tumor often got smaller after treatment — colon cancers transplanted into the mice shrank to less than one-third of their original size, on average. And in five mice with breast cancer tumors, anti-CD47 eliminated all signs of the cancer cells, and the animals remained cancer-free 4 months after the treatment stopped."
While, you have a point
that mice and humans are different enough that most cures don't translate 1:1 to humans.
at least it has been tested on
human breast, ovary, colon, bladder, brain, liver, and prostate tumors that have been transplanted into mice
, rather than just on mice anatomy.
Yeah this seems to be the problem with all chemotherapy drugs. They target fast growing tissue, including the immune system. Being treated for these conditions can make you wish you were dead.
http://michaelsmith.id.au
The authors share your concern. From the paper:
A concern in translating this therapy to human application is the potential for toxicity. CD47 is highly expressed on tumor cells, but also at varying levels on normal (nontumor) cells. However, here we demonstrate that blockade of CD47 in immune competent mice produces an effective antitumor response without unacceptable toxicity, albeit with a temporary anemia.
What about non-tumor cells, which also display this cell determinant?
They will die. But, from TFA: "CD47 is overexpressed on cancer cells". Cancer treatment is about destroying much more cancer cells than healthy ones.
I'm no expert in these things, but AFAIK the process goes something like this:
Each of these steps can take months. Some of it's political and administrative wrangling, some of it's just that the test itself will take some time before you can be sure of the results. A drug can fail at any one of these stages and it's back to the drawing board (or maybe the test tube).
The whole process takes years. Yet newspapers often start reporting about "miracle cure" drugs that have only just completed the first round of live animal trials. Which is why you hear about all sorts of miracle cures that never see the light of day.
Probably because he's a fraud:
https://en.wikipedia.org/wiki/Stanislaw_Burzynski
Miraculous claims require miraculous proofs. And doctors aren't just sitting on the sidelines waiting to be paid more to kill more people, despite what you might think.
I understand you. And I agree with you. I got 10 chemos and stem cell transplant 5 years ago. Yes, it was living hell. But seeing my kids grow up now makes it 1000 times worth it.
That's the nature of drug testing. You test it out in several animals of varying levels of similarity to humans before you start testing in humans. Mice are a common starting point because they're inexpensive and small, and you can run trials with thousands of mice. Also, mice sort of self-destruct if things start going badly in them, they are fairly fragile. So they make good canaries because when things are going badly, the signs are not often subtle.
Plenty of compounds show promising results in mice that prove to have reduced results in later trials with more complex animals or in humans, or show side effects only later in the drug study regime. Conversely it's almost certain that there are compounds out there which would provide amazing results in humans, but which failed early stage drug studies in animals. It's just not a great idea to be testing drugs for the first time in humans without some idea as to what the outcome would be; the fatality rate in animals is pretty high, and you can purposely infect them to treat for a specific disease. There are drugs that even with this prep work still fail in clinical (human) trials, either because of efficacy problems or because of unexpected or more-severe side effects, or some combination (if it's effective but with bad side effects in animals, then not very effective and with horrible side effects in humans, it will be rejected).
The study in this article is the very earliest stage. Usually they do tiny studies like this as the very first trial. Many, many drugs produce interesting results at this stage, and fail the very next set of studies (statistically large populations, which 10 mice is not, even with extremely promising results such as this). The chances of such a drug making it to clinical trials is vanishingly small, almost all compounds fail, only a few ever make it.
Slay a dragon... over lunch!