Cancer drug fights osteoporosis

A breakthrough treatment means patients may need just one annual dose, AINSLEY THOMPSON finds.

Fourteen months ago it took osteoporosis sufferer Rennie Urquhart 20 agonising minutes to get out of bed.

Today he can do it normally without fear of breaking bones.

The improvement in the Wellsford man's health is thanks to a drug called zoledronic acid, which is being tested for the treatment of osteoporosis.

The drug's significance was uncovered in an international study led by Professor Ian Reid of Auckland University.

One of the most impressive attributes of the drug for sufferers is that they may need only one injection a year to control the disease. Up to 400,000 New Zealanders suffer from the disease.

The study, published last week in the New England Journal of Medicine, tested the drug on 351 volunteers and discovered that an annual 4mg dose of zoledronic acid was just as effective in strengthening bones as other osteoporosis treatment taken daily.

Zoledronic acid is already approved for use in cancer patients to treat the high levels of calcium found in people with certain types of the disease.

If confirmed, the discovery would be a major advance in the treatment of osteoporosis, which affects 200 million people worldwide, especially in affluent societies, because it would eliminate the need for constant drug therapy.

Since Mr Urquhart was given the injection last May, the bone density in his vertebrae has improved by 10 per cent and the density in his hip by 3 per cent.

Professor Reid said the drug was potentially a watershed in the treatment and prevention of osteoporosis.

"This is going to surprise and astound a lot of doctors and please a lot of patients because people don't like taking tablets.

"It's potentially a huge change in treatment - and, I think, prevention - of osteoporosis.

"I think it almost comes into the category of a 'flu shot, rather than taking pills every day and having side-effects."

Professor Reid said he and his colleagues were amazed when they saw how long the effects lasted. Benefits of the injections persisted beyond one year.

Twelve months after the initial shot, Professor Reid said, "the effect really wasn't wearing off. Bone densities, if anything, were trending upward" and the destruction of old bone tissue, which helps to weaken bones, continued to be suppressed.

But the study has not yet answered a key question: whether the treatment actually prevents fractures.

Such tests, expected to take about three years, were about to begin or were under way, Professor Reid said.

Osteoporosis New Zealand spokeswoman Julia Gallagher said they were excited about the discovery.

Around 56 per cent of women and 29 per cent of men over the age of 60 suffered from osteoporosis in New Zealand, she said.

"The way we see it is there will be a significant increase in the number of people who suffer from osteoporosis being treated, because if just a single annual injection [is needed], the cost of that will obviously be considerably less than taking tablets every day."

One of the problems with current medication is annoying side-effects in some people. "That reduces patient compliance," she said. "The side-effects are irritating and they think, 'I can't be bothered with this', so they don't take the drug."

Mr Urquhart, who was diagnosed with the disease 14 months ago, has firsthand experience of the side-effects of the traditional medication.

After he had taken it he had to stand upright for half an hour or he would later suffer from bad indigestion and heartburn.

He has not experienced any side-effects with zoledronic acid.

He used to have to take 60ml of morphine a day; now he takes only 20ml.

But other volunteers who have tried the drug have reported some side-effects.

Most of them were mild, but included muscular and skeletal pain, fever and nausea.

Ten per cent of the people who received the highest dose of the drug reported a serious side-effect, but so did 5 per cent of the people who got a placebo.

The rate of nausea was 5 per cent among placebo recipients, compared with 13 per cent who got the annual 4mg dose.

US National Osteoporosis Foundation clinical director Dr Felicia Cosman said the thought of a once-a-year treatment was mind-boggling.

But she said women should still make sure they got enough calcium, vitamin D and exercise.

"No drug works as well in the absence of making other changes in the lifestyle."

Zoledronic acid or zoledronate is sold under the brand name Zometa by the Swiss-based company Novartis, which paid for the study.

The drug has not yet been approved for osteoporosis. Instead, it is used to treat people with some types of cancer.

It has also been approved by the United States Food and Drug Administration as a treatment for certain bone cancers. Novartis has begun enrolling patients for two big studies of the drug: a three-year study of 7500 women who have been through menopause, and a two-year look at 4500 men and women who have had a hip fracture from osteoporosis.

Novartis said it did not know how much the drug was likely to cost.

FACT FILE

* Osteoporosis is a disease of the skeleton caused by an imbalance in the body's bone-rebuilding cycle. Bone tissue deteriorates, making bones more prone to fractures.

* Bone is continuously replaced much like skin cells, keeping the skeleton healthy. But in women approaching menopause, the balance of bone removal and reforming begins to shift and more is lost than replaced.

* In New Zealand about 56 per cent of women and 29 per cent of men over the age of 60 will suffer a fracture caused by osteoporosis.

* Symptoms include unexplained back pain, height loss, recurrent fractures, or fractures resulting from minimal trauma.

* Young people can get osteoporosis.

* Preventive measures include eating a balanced calcium-rich diet, staying active, spending time in the sun for vitamin D, limiting alcohol intake, and not smoking.

* Osteoporosis is hard to detect. A bone-density scan is the best diagnostic tool.

- additional reporting, agencies

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