Bone drug deal promises plenty

By MARTIN JOHNSTON health reporter

Auckland University researchers have teamed up with an international drug company to develop a treatment that could reverse a common bone-thinning disease affecting 200 million people worldwide.

The osteoporosis drugs could earn the university huge royalties - sales of treatments are expected to reach US$9.3 billion ($20.2 billion) within 10 years.

About 260,000 New Zealanders aged over 60 are affected by osteoporosis. It disproportionately affects women and puts people at higher risk of breaking bones.

The university's commercial division has struck a deal with Melbourne company Metabolic Pharmaceuticals to commercially develop the drugs.

"If successful, these compounds could bring help to an increasingly large proportion of the population who will be affected by osteoporosis," said Associate Professor Jill Cornish, one of the scientists who discovered the drugs.

Medicines now available aim at slowing loss of bone density, but the Auckland drugs could be among the first to promote bone growth, as well as reducing bone-thinning.

The experimental drugs are fragments of hormones found at higher levels in people who are obese. The research arose out of the finding more than a decade ago that obese people have fewer bone fractures.

"We showed that bone density is related to body weight and that the body-fat component was the major predictive factor," said Professor Ian Reid, of the university's bone research group.

"That set us off looking for hormones that might be higher in fat people that would have a beneficial effect on bones. In fact we've discovered a whole lot and we are continuing to discover more."

The drugs licensed to Metabolic are fragments of amylin and adrenomedullin. They have shown promising results in making animal bone cells grow more quickly.

"We've managed to produce fragments of each of these hormones that preserves its bone activity but loses its other major activities in the body," Professor Reid said.

Amylin's main function is to regulate energy metabolism. Adrenomedullin lowers blood pressure.

Professor Reid said the Australian deal meant the drugs could now be tested more extensively on animals and, if satisfactory, tried in humans.

The drugs could be on the market in five to seven years.

Professor Ailsa Goulding, an Otago osteoporosis expert, welcomed the bid for drugs that did more than slow bone loss.

"If we could switch on making new bone when we like it's obviously a good way of strengthening the skeleton."

Osteoporosis facts

* Bones lose density and become more brittle with age.

* Bone loss affects 56 per cent of women and 29 per cent of men aged over 60 - about 260,000 New Zealanders.

* Risks can be reduced by adequate calcium intake from food, including dairy products, some fruit, vegetables and fish, and from supplements.

* Existing drugs can reduce loss of bone density.

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