The wonder drug that can rebuild crumbling bones

ANEW drug that rebuilds crumbling bones could spare thousands of elderly people from debilitating fractures. More than three million people in the UK have osteoporosis, which causes the bones to become fragile. While the condition is four times as common in women, men are affected too – and are likely to suffer more complications.

Bone cells are constantly dying and being renewed, but in patients with osteoporosis not enough new bone forms. This means they become more porous, weaker and more prone to fracturing. The condition often goes undetected and can cause no symptoms – until bones break.

Every year, about 500,000 people in the UK with osteoporosis will receive hospital treatment for fractures as a result of very slight falls and knocks. Broken hips, wrists and spinal vertebrae are common in people with the condition.

Professor David Reid, a private consultant rheumatologist and senior medical adviser to the Royal Osteoporosis Society Bone Research Academy, said: ‘Spinal fractures can be disabling and extremely painful. The problem is that you can’t just put someone with one in plaster or a brace.

‘It can be really uncomfortable to move about – and takes about three months to heal.’

Over time, some people who suffer spinal fractures may also develop a stooped posture, as the spine struggles to support the weight of their body, and this can lead to breathing difficulties. Patients with osteoporosis are currently offered two main types of drug treatment. The first slows the rate of bone loss, while the second encourages new bone to form.

For almost a decade, no new drugs have been deemed effective or safe enough to be given to patients.

But at the end of last year, the European Medicines Agency approved romosozumab, a new type of bone-forming treatment, for some post-menopausal women with severe osteoporosis.

Osteoporosis is more common in women than men – particularly after the menopause – because of falling levels of the female sex hormone oestrogen, which is vital for healthy bone formation.

The new treatment, which has the brand name Evenity, works by blocking sclerostin, a substance that stops new bone cells forming.

A study found that post-menopausal women with osteoporosis who were given the new drug had a 73 per cent lower chance of developing a new spinal fracture after a year, compared with women who received a placebo.

The treatment has also been shown to increase the density of the thigh bone, hip and vertebrae.

‘The advantage of this drug compared with other existing bonebuilding drugs, is that it seems to build bone in the spine more quickly,’ Prof Reid says, ‘but it also builds bone at the hip, which the other bone-forming drugs don’t.

‘The assumption is that, based on the change in bone density, the risk of other fractures would also be significantly reduced.’

However, it is not suitable for everyone. Osteoporosis patients at a high risk of a heart attack or stroke should not be given the drug, as one study found it could increase the chances of either happening.

Romosozumab is self-injected by patients once a month for 12 months. The medication must be administered in two separate injections in two different areas. Most patients choose to inject one dose in each thigh. After a year, patients are moved on to treatments that slow the breakdown of the newly thickened bones.

Romosozumab is now being used to treat UK patients in private practice but is not yet available on the NHS. Its appraisal has been delayed by spending watchdog, the National Institute for Health and Care Excellence, as a result of Covid-19.

At the moment it is deemed suitable only for patients with severe osteoporosis who have recently had a fracture and are likely to suffer another. But Prof Reid hopes that in the future, bone-forming drugs could be used in people with a less severe form of the condition.

‘I believe in five to ten years’ time we will be treating a lot more people who have had a fracture and who have low bone density with bone-forming drugs,’ he says.

‘I think that it will become the first-line treatment.’

A spokeswoman for the Royal Osteoporosis Society, adds: ‘It’s taken 15 years of research to get to this point, and it’s been nine years since the last osteoporosis drug was approved. This really is a positive step and provides improved patient choice.’