Please turn on javascript in your browser to play chess.
Science Forum

Science Forum

  1. 05 Sep '14 17:00 / 4 edits
    a drug called Keytruda has been tested on more than 600 melanoma patients and "showed significant long-lasting responses" (a slightly vague statement I think ) to advanced melanoma and now this drug is approved for wide-scale use. But the link doesn't say exactly what proportion of those patients are still alive and how many are actually cured etc so I don't know exactly how significant this advance really is although the link certainly makes it sound significant.
    The drug works by suppressing a protein that the cancer produces to stop the immune system from attacking it. With that protein suppressed, the patient's own immune system then attacks the cancer.


    http://medicalxpress.com/news/2014-09-fda-game-drug-melanoma.html
  2. Standard member sonhouse
    Fast and Curious
    08 Sep '14 13:09 / 1 edit
    Originally posted by humy
    a drug called Keytruda has been tested on more than 600 melanoma patients and "showed significant long-lasting responses" (a slightly vague statement I think ) to advanced melanoma and now this drug is approved for wide-scale use. But the link doesn't say exactly what proportion of those patients are still alive and how many are actually cured etc so I don't kn ...[text shortened]... then attacks the cancer.


    http://medicalxpress.com/news/2014-09-fda-game-drug-melanoma.html
    Statistically 600 is a rather low number. If I recall correctly, they want something like 2 to 3 thousand samples to get a better handle on the results.

    That said, it is a promising result. So the next step would be larger studies.

    Do you know if this study was double blind?
  3. 08 Sep '14 13:23 / 6 edits
    Originally posted by sonhouse
    Statistically 600 is a rather low number. If I recall correctly, they want something like 2 to 3 thousand samples to get a better handle on the results.

    That said, it is a promising result. So the next step would be larger studies.

    Do you know if this study was double blind?
    I don't know if it was double blind. But somehow I wouldn't think the number of them dying or showing a slower or faster cancer spread would be greatly effected by the placebo effect!
    Having said that, I am still rather concerned that they didn't give specific statistics on that (I wonder "why didn't they?" ) and also their slightly vague statement of "...showed significant long-lasting responses..." without elaborating on exactly what they mean by that. These, to me, are not good signs.
  4. Standard member sonhouse
    Fast and Curious
    08 Sep '14 19:38
    Originally posted by humy
    I don't know if it was double blind. But somehow I wouldn't think the number of them dying or showing a slower or faster cancer spread would be greatly effected by the placebo effect!
    Having said that, I am still rather concerned that they didn't give specific statistics on that (I wonder "why didn't they?" ) and also their slightly vague statement of "...sho ...[text shortened]... ses..." without elaborating on exactly what they mean by that. These, to me, are not good signs.
    Did you see the original print? It might be more specific than the general public release.
  5. 08 Sep '14 19:50
    Originally posted by humy
    and also their slightly vague statement of "...showed significant long-lasting responses..." without elaborating on exactly what they mean by that. These, to me, are not good signs.
    Cancer generally is never 'cured'. It may recur later in life. Generally the results of cancer treatment is not measured in terms of cure vs non-cure, but rather reduction in tumor size, length of extended life span etc.
  6. Standard member DeepThought
    Losing the Thread
    09 Sep '14 15:44
    Originally posted by humy
    I don't know if it was double blind. But somehow I wouldn't think the number of them dying or showing a slower or faster cancer spread would be greatly effected by the placebo effect!
    Having said that, I am still rather concerned that they didn't give specific statistics on that (I wonder "why didn't they?" ) and also their slightly vague statement of "...sho ...[text shortened]... ses..." without elaborating on exactly what they mean by that. These, to me, are not good signs.
    The article says it was a phase I trial, which is typically a very small trial on healthy volunteers to ensure the drug doesn't cause harms. They have conducted a trial on 600 cancer patients and the article implies there is no standard treatment arm, which would be normal in a phase I trial as they are looking for harms rather than efficacy. This trial is strange for a phase I trial as it is huge, normally they have around 10 volunteers, and it is on cancer patients rather than healthy volunteers. Since they do not talk about a comparison arm they appear to be comparing with baseline. Until they have done a large trial where the comparison is with a standard treatment group and at least five years follow up then there is no proof that this drug is any good.

    Another point is that they are looking at surrogate measures such as tumour size. This is a technical outcome, not a clinical one. Clinical outcomes are things the patient cares about such as mortality, pain, well-being. The reason for this distinction is that a procedure's technical success is not the same as clinical success - summed up by the old quote: "The operation was a complete success - but the patient died."

    What you were reading was marketing, not science. The theoretical description of the procedure is promising, but what are the adverse effects? Is the immune system permanently off the leash? Will people survive for a couple of years only to be destroyed by their own immune systems? Is it really better than standard treatment? If I'm right and there is a single arm with comparison with baseline then we don't actually know if the drug is any good. All they've shown so far is that the drug doesn't kill cancer patients quickly.
  7. Standard member sonhouse
    Fast and Curious
    10 Sep '14 08:04
    Originally posted by DeepThought
    The article says it was a phase I trial, which is typically a very small trial on healthy volunteers to ensure the drug doesn't cause harms. They have conducted a trial on 600 cancer patients and the article implies there is no standard treatment arm, which would be normal in a phase I trial as they are looking for harms rather than efficacy. Th ...[text shortened]... ug is any good. All they've shown so far is that the drug doesn't kill cancer patients quickly.
    So the motivation for this article is to generate funds for the next round?
  8. 10 Sep '14 09:55 / 2 edits
    Originally posted by sonhouse
    So the motivation for this article is to generate funds for the next round?
    It is generally healthy to be skeptical in science. However, there is a point where skepticism becomes irrational paranoia: it is not a reasonable assumption that every article and every medical study and every research is done by psychopathic greedy people for pure money motive and completely devoid of any compassionate or moral concerns. It is actually quite unusual, even for a relatively greedy person who's primary motive is profit, to never feel or have any compassion whatsoever for others. I would guess most such true psychopaths end up in jail and generally wouldn't have much of a career in science.
  9. Standard member DeepThought
    Losing the Thread
    10 Sep '14 15:20
    Originally posted by sonhouse
    So the motivation for this article is to generate funds for the next round?
    The article was copied from a U.C.L.A. public relations statement. The drug could well be good, but the problem is that it hasn't yet gone through the full set of clinical trials. Until it has we don't know if it works, who it should be prescribed to, and whether there are long term adverse effects. A large trial with one arm and no follow up yet doesn't really cut it as there isn't a proper comparison and the long term adverse effects could be worse than the original disease. My worry is that the drugs industry are pushing for short-cuts in the accreditation process and something like Thalidomide could be approved for use in the wrong population.