Re-purposing old drugs for cancer: sometimes old ‘uns can be good ‘uns

Today's post is from our chairman Robin Daly who discusses how the re-purposing of drugs could unlock new potentials for treating cancer.

The re-purposing of old drugs for cancer is making headline news this year. So is this really ‘new’? Is it even ‘newsworthy’? Or is it simply yet another of those endless ‘cancer breakthrough’ stories so beloved of the media?

To answer the first question: this is far from a new idea. The incidental positive effects of some old, safe, tried and tested drugs on cancer has been noted for many years. For example, metformin, given to people with diabetes to control their blood sugar levels, has the striking effect of transforming their risk of developing cancer from higher than normal healthy people to lower. The thing that is new is the level of interest around this phenomenon.


You might have expected, given the appalling, runaway cancer statistics and the spiralling cost of treatment, that an observation such as this effect of metformin might have been heralded as potentially another groundbreaking medical breakthrough along the lines of Fleming spotting the mould in his petri dish that led to penicillin. But in the event, this, along with dozens of other similar observations, was noted as ‘interesting’ and relegated to a ‘footnote’ of medical history.

Fortunately, a few pioneering doctors have noticed these medical ‘footnotes’ and begun using these drugs as part of their integrative protocols to control cancer. One of the most instantly striking features of the drugs is their extraordinary diversity. Apart from metformin, they include an anti-parasitic drug called mebendazole; a statin, one of a class of drugs developed to lower the risk of heart attacks but increasingly seen to be ‘barking up the wrong tree’; an old antibiotic, doxycycline; and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. On the face of it, this is a
completely random collection of unconnected medicines. Certainly within the current orthodoxy of cancer as a genetic disease, caused by defects in the genes leading to changes in DNA and cell mutation, it’s hard if not impossible to make sense of it all.

This is where another old idea comes to the rescue: in 1924, the scientist Otto Warburg put forward the notion that cancer has essentially one root cause - damage to the cells’ energy generators, known as mitochondria1 (1).  Again, this looks like one of those breakthrough scientific observations - and indeed Warburg eventually received a Nobel Prize for making it - but all too soon it found itself relegated to the category of  an interesting observation, merely an effect of the basic genetic problem. But if we dust off Warburg’s theory and use it to illuminate these random pieces that appear to come from completely different jigsaws, we can start to see how they do in fact fit together in a way that makes complete sense. We can see how all these drugs have a disruptive effect on the ‘hallmark’ feature of all cancer cells - their damaged metabolism.

The reason for much of the recent media exposure is that a group of scientists and oncologists have launched a low budget trial in London* in which they are enrolling late stage patients with any type of cancer on a programme of four re-purposed drugs. This programme can be added to existing standard treatments. Very unusually, the trial facilitators take an active interest in all the ‘integrative’ approaches a patient may be using such as dietary interventions, oxygen therapies, vitamin C infusions or heat treatment (hyperthermia), and take careful note of these.

Since they are fully signed up to the metabolic theory of cancer, such non-toxic approaches make complete sense as additional ways of targeting cancer’s trademark metabolic features, whilst simultaneously supporting healthy cells. I understand that early results look very promising and that the trial is still open to further applicants.

How could we have overlooked such a potential goldmine of methods to control cancer? The combination of a statin and metformin alone has been observed to reduce cancer risk by a staggering 80% (2). There is a serious danger of the trial results making the best of cutting-edge cancer treatments look ridiculous - not to mention ridiculously expensive. The problem of course is that the main driver for healthcare innovation is business, and sadly health is only a secondary consideration for business. Their interest is in profits, and there are clearly no big bucks for the corporates in this particular goldmine. Out-of-patent drugs are cheap. The four drugs in the trial come in at less than £20 per month, hardly worth mentioning alongside something in the order of £5000-£20,000 per month for targeted gene therapy.

The obvious fact that we cannot afford to entrust the health of our nation to corporations must be assimilated and acted on by our government if we are to turn around the headlong long rush into multiple chronic conditions. For too long the food and pharmaceutical industries have been profiting at the expense of our nation’s health. To begin to turn the tide, we need strong government initiatives to drive unprofitable research into cheap solutions and to control the parameters of what is allowed into our food supply.

To return to the other two questions I asked at the outset: I’d say re-purposing of drugs  certainly is newsworthy. In fact I’d say it needs as much exposure as it can get to alert the public to the realities of 21st century ‘cancer research’. And as news, I think - I sincerely hope - it just might be a real ‘cancer breakthrough’ this time.

Read more blogs from Robin here

* Care Oncology Clinic: http://careoncologyclinic.com

1. Warburg, O. (1956) On the origin of cancer cells. Science 123 (3191), 309-314.
Warburg, O., Posener, K, and Negelein, E. (1924) Ueber den stoffwechsel der tumoren. Biochem Z 152, 319-344. OpenURL

2. Khurana, V., Sheth, A., Caldito, G. and Barkin, J.S. (2007) Statins reduce the risk of pancreatic cancer in humans: a case-constrol study of half a million veterans. Pancreas 34 (2), 260-265.
DeCensi, A. et al. (2010) Metformin and cancer risk in diabetic patients: a systematic review and meta-analysis. Cancer Prevention Research 3 (11), 1451-1461.