May 25, 2015

Cancer vaccine?

The segment was about research from the Malaghan Institute, who are working on ways to encourage a patient’s immune system to attack tumours. They say, in a press release

While the research will focus specifically on targeting melanoma, it is anticipated that the methodology being developed could be applied to other cancers in the future.

The therapeutic vaccine approach differs from the preventative vaccines used to protect against diseases such as measles or the flu because the cancer vaccine is designed to be given to an individual after they have already shown signs of disease.

“It is known that white blood cells called T cells can kill tumour cells,” says Dr Hermans. “The cancer vaccines, which are custom-made for each cancer patient, are designed to stimulate the activity of these cancer-fighting immune cells.”

As the press release makes clear, the term ‘vaccine’ is technically correct, but liable to mislead: these are customised immune-system treatments specific to one tumour in one individual. It’s nothing like the measles vaccine that you get as an infant for lifetime protection.

Like other research groups, the Malaghan Institute are starting with melanoma. There are at least two reasons melanoma is a good place to start. The simple reason: until very recently, metastatic melanoma was completely untreatable, so anything would be an improvement. There’s also a complex reason: melanoma occasionally shrinks or vanishes of its own accord, apparently more often than other tumours do. The spontaneous regressions are presumably thanks to the immune system waking up and realising the tumour is a problem, so melanoma is a good starting point if you want to find out how this happens and encourage it to happen more often.

The basic problem is that the immune system tends to see cancer cells as part of the patient, since, fundamentally, they are. The Malaghan Institute has a innovative addition to the treatment, a chemical that scares specific parts of the immune system into action. They expect that combining this with the existing tumour vaccine approaches will give a more reliable result.

Malaghan got $4.5 million from the Health Research Council to work on this, which is pretty impressive given the HRC budget and competition, but the melanoma vaccine is still in the initial stages of testing. The majority of promising treatments going in to Phase I clinical trials don’t end up being useful. Even if this one does, that’s no guarantee it will work for other types of cancer, and while it’s a vaccine in the sense that it works by stimulating an immune reaction, it’s nothing like the vaccines we give to kids.

It’s not a good time to criticise Campbell Live, but although the Malaghan’s research is truly impressive, it’s not a general-purpose cure for cancer anytime this decade. And there’s a basic principle that you shouldn’t say “cure” in the headline unless there’s a cure.

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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Bart Janssen

    I think you’re being a tad harsh. They didn’t state it was a cure but asked the question. They also were pretty clear in the item itself that it doesn’t work all the time – one out of three in the US trial and gave the Malaghan folks a good chance to deliver the cautious message.

    Nevertheless, the approach IS stronger than previous try-a-random-chemical-and-not-quite-kill-the-patient methods. So I thought a slightly more optimistic story was resonable.

    2 years ago

    • avatar
      Thomas Lumley

      On the other hand, melanoma vaccines weren’t new when I first worked in cancer research twenty years ago. And while they are more hopeful than generic chemo, it’s not clear they are more hopeful than antibodies to specific tumour markers — which are already working in melanoma.

      2 years ago