A new lease of life for pills that didn't pop

With the recent launch of the International Pharmaceutical and Biotechnology Exhibition (PABME) in the UAE – the first event of its kind in the region – the Middle East's pharmaceutical industry has been attracting more attention than ever. And deservingly so: The total value of the Middle East market currently stands in excess of $10 billion (Dh37.5bn) and is registering growth rates of between 15 per cent and 18 per cent.

However, because international pharmaceutical manufacturers are currently struggling to launch new products onto the market, more companies are resurrecting old medicines that initially failed in the developmental stages.

And the reason this method is working is due to newly discovered links between genes and diseases.

Since the completion of the human genome six years ago, scientists have been scanning human DNA with a precision and scope once unthinkable and rapidly finding genes linked to cancer, diabetes, chronic bronchitis, and other illnesses. As a result, many companies are now finding themselves aiming towards the goal of personalised medicine – creating drugs that could treat individuals with specific medical conditions with the greatest efficiency, and the least side effects.

Several factors – including age, diet and lifestyle – can influence a patient's response to medication.

However, it is an individual's genetic make-up that has the greatest impact, and therefore, scientists are relying on pharmacogenomics – the study of an individual's genetic make-up and its effect on drug response – to find uses for drugs that were once deemed ineffective.

"It is a rising trend and an important one," Thomas Petri, Medical Advisor, Medical Affairs for Eastern Europe, Central Asia, Russia, Middle East and Africa, Bayer Schering Pharma, Germany told Emirates Business.

"Researchers are finding that they can produce successful drugs that target specific variants of genes, and thus can find cures for conditions that couldn't be treated effectively before.

"Additionally, producing a drug from scratch can be a very long and costly process, which is why scientists are turning to old trials."

On average, drug development can take up to 10 years or more, and according to a study on the cost of drug innovation published in the Journal of Health Economics, failures can cost companies a lot – from $15 million per compound at the first stage of human testing to $86m in late-stage trials.

While the markets for personalised medicine is smaller than for those that treat the general population, more pharmaceutical manufacturers are now realising that they can make large profits from the concept due to the fact that patients are more likely to use, and stick with, a tailored medicine that works better than a "one-size-fits-all" drug.

An example of this is biotechnology giant Genentech Inc's Herceptin, which is taken by women with breast cancer who have a particular variant of the HER-2 gene. In the US alone, the drug made an estimated $1.3bn in sales last year.

Now more drugs are coming out of the woodwork, most notably Rifapentine, an antibiotic long abandoned as a weak low-dose treatment for tuberculosis (TB). Its commercial production was stopped years ago because demand for the product was so low.

However, according to a study published in the Public Library of Science Journal recently, disease specialist Eric Nuermberger's studies in mice may have found a renewed purpose for the drug – this time as a potent high-dose fighter against the most common and actively contagious form of the lung disease. In fact, the antibiotic is so promising as an initial treatment for active TB that clinical trials are scheduled to begin by June in at least eight countries.

"It's a huge advantage to have a drug that's already government-approved, and an equally great surprise to know that it was there all the while," said Nuermberger, who is an assistant professor at the John Hopkins School of Medicine in the United States.

"People infected with TB are desperate for better therapies to combat the infection, therapies that can work more quickly and thus limit its chances to spread.

"And having the ability to more effectively treat the most common form of the disease, so-called drug-susceptible TB, is a key step in holding off multi-drug-resistant strains from developing, too."

In the paper, Nuermberger noted that most of the antibiotics currently used to treat TB were developed in the 1950s or 1960s, and few new medications have appeared since.

Rifapentine, approved by the US Food and Drug Administration (FDA) in 1998 for treating widespread drug-susceptible TB, was initially developed as a less cumbersome once-weekly tablet. But the drug "was never really considered effective in low doses when compared to the gold standard, daily high-dose regimens with Rifampin," another antibiotic, which was FDA-approved in 1968.

Meanwhile, leaps in DNA-scanning technology have opened the door to a flood of new reports about genetic links to disease, which could result in more types of drugs being rediscovered.

Since 2005, studies with the gene-scanning technique have linked nearly 100 DNA variants to as many as 40 common diseases and traits, scientists noted last month in the Journal of the American Medical Association.

"There have been few, if any, similar bursts of discovery in the history of medical research," two Harvard researchers declared last summer in the New England Journal of Medicine. While the basic gene-scanning technique is not new, its popularity has exploded recently because of cost-cutting advances in technology and discoveries about the genome.

"It lets you go searching for that needle in the haystack," Michael Watson, executive director of the American College of Medical Genetics, said.

It's a big haystack. DNA is made up of long sequences of building blocks composed from a four-letter alphabet: A, C, G and T. The human genome contains approximately three billion letters, and individuals have slightly different DNA sequences. People commonly differ in what letter they have at about ten million positions along the full genome. Some may have a T where most people have a C, for example.

And those single-letter variations are key to the genome-wide scans. Scientists compare DNA from a large number of people, some sick with a particular disease, and others healthy. They can look at a half-million or more positions to see what letter appears. If sick people tend to show a different result than healthy ones, then it's a red flag.

It suggests that some genetic influence on the risk of that disease comes from that spot or nearby. So it gives scientists a specific place to look more closely for a disease-promoting gene. In practice, genome scans can be big undertakings.

Scientists in the US and Denmark are searching blood samples from 7,000 babies and new mothers in the countries for genetic variations that raise the risk for premature birth. DNA will be extracted, and early this summer, more than half a million spots on the microscopic strands from each mother and baby will be assessed for clues to where the genetic variations may lie.

The DNA will be analysed at the Center for Inherited Disease Research at Johns Hopkins University in Baltimore. Robots will put a tiny drop of DNA-bearing solution from each person onto a clear glass slide roughly the size of a business card, with four drops per slide.

The lab's DNA scanners, blue boxes each about twice as big as a desktop printer, will reveal what DNA "letter" appears in more than 580,000 spots in the genetic material, said lab director Kimberly Doheny. Even five years ago, such a detailed examination of DNA from so many people would have been inconceivable. Genome scans offer some major advantages over previous gene-hunting techniques.

Scientists don't have to start by guessing what genes might be involved in a disease, or confine themselves to families where a tendency to an illness is inherited.

And the genome-scan approach reveals genes with only a subtle influence on the risk of getting sick, too slight to be found by earlier methods.

That's just the kind of gene that plays a role in common illnesses like heart disease.

Even if its impact on risk is small, a newly found gene could be a bonanza to scientists if it reveals something new about the biology of a disease. That in turn could give hints for resurrecting treatments, resulting in potentially thousands of patients being treated. (With input from AP)

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