Can aspirin prevent cancer?

The story of a failure that turned into a success

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How it became a drug created to treat angina the most famous little blue pill against erectile dysfunction, is due to luck. In a happy scientific situation.

In the 1980s, Pfizer began testing a drug, sildenafil, to relax the coronary arteries and improve blood flow to the heart. Clinical trials, however, were unsuccessful, the desired cardiovascular outcome was unanswered.

Until suddenly, researchers discovered that, among the side effects of taking sildenafil, some patients had reported strong and persistent erections. Thus entered the first stone for the release of the famous Viagra. The story of a failure that turned into a success.

Unbeknownst to them, this drug became the model for a new strategy for testing and expanding, in a more flexible way, the therapeutic arsenal against any disease: drug repositioning, which means finding new diseases in which existing drugs with different initial indications can be used.

Old acquaintances of pharmacies, such as aspirin or the antiepileptic drug topiramate, are already being investigated in this direction. Aspirin, a historical analgesic and antipyretic that has also found a place as an antiplatelet agent over the years, has been linked to the treatment of colon cancer: a prognostic study published in the journal Jama Oncology linked the use of aspirin to a reduction 18% of the risk of developing colorectal cancer. Research is also currently monitoring its effectiveness in a subset of lung tumors.

According to the Spanish newspaper "El Pais", it takes 10 to 15 years and an investment of about 2,5 billion euros for a drug to be licensed and marketed. The development of a drug, write in their book "New uses for old drugs", published last year by the National Research Council of Spain (CSIC), Nuria Camigio, Maria del Carmen Fernandes and Maria Merthedes Jimenez, is a "race with obstacles ": 10.000 substances may start at the end and only one may reach the end. Or none. The drugs on the market today are the winners of all these long and expensive roadblocks. Drug targeting, however, is an alternative that significantly reduces both the time and the financial resources required.

These are drugs that have already passed the safety and toxicity tests, so the researchers are escaping the preclinical stages. "We save time, money, and the animals we use in the experiments," said Nuria Campiglou, a chemistry doctor and researcher at CSIC. That way, the leave can come in three years. And the cost of launching a re-targeted drug on the market, to be reduced to 300 million.

There are already many examples of old medicines with new lives. Cyclosterine, used for urinary tract infections, is now used for tuberculosis with resistance to active drugs. Mifepristone, normally used to induce abortion, is being tested for psychotic depression. Raloxifene, used to treat osteoporosis, now has a new life against breast cancer. As for thalidomide, which was given to pregnant women in the 1960s to fight nausea and ended up causing serious abnormalities in thousands of newborns around the world, it has revived its bad reputation after proving its effectiveness against a form of leprosy: in 1998 , was approved in the US with this new indication in 2012, for multiple myeloma.

The big data explosion

There are of course cases of failure. The antiepileptic topiramate, although it has been shown to be effective in obesity, has failed in its attempt to combat irritable bowel syndrome. The antibiotic ceftriaxone has been shown to be ineffective against lateral myotrophic sclerosis. The antihistamine latrepiridine failed to treat Huntington's disease. But the scientific community is not discouraged.

Above all, because re-targeting drugs is the best alternative when it comes to finding solutions to rare diseases, "where little money is spent because the number of patients is small," says Cambio. After all, the explosion of big data and the development of new technologies have given great impetus to this re-targeting. In their book, the three researchers estimate that up to 75% of the drugs currently available in pharmacies may have new therapeutic uses.

in.gr