New Mounjaro and Ozempic side-effect could benefit thousands

They have already taken the weight-loss sector by storm – now the blockbuster drugs Ozempic and Mounjaro could do the same for lymphoedema, a lifelong, progressive swelling disorder that often follows cancer treatment.

An estimated 500,000 people in the UK live with the condition, where arms or legs can swell to double their normal size, causing pain and limiting movement, due to a build-up of fluid in the body’s tissues.

The condition can leave sufferers struggling to get dressed, put their shoes on over swollen feet, or carry out everyday chores such as washing-up and carrying the shopping. Twice as many women are affected as men and about one in five who survive breast cancer will develop it.

But now a groundbreaking clinical trial in the US, involving 110 people with lymphoedema, is to investigate whether regular injections of weight-loss jabs could reduce the swelling, improve mobility and restore their quality of life.

Once a week for six months, the study participants will inject themselves with either semaglutide (the drug used in Ozempic) or tirzepatide (used in Mounjaro), as researchers assess changes in limb size and fluid levels.

The trial has been set up at the Institute for Advanced Reconstruction in New Jersey, in the US, after a study last year – involving almost 4,000 breast cancer patients undergoing surgery including having lymph nodes removed – found that those taking the weight-loss jabs before their operation were 86 per cent less likely to develop lymphoedema.

The jabs seemed to reduce the risk of it developing from about one in three patients to one in ten, reported the journal Frontiers in Pharmacology.

The researchers said this may be down to several factors. One theory is that GLP-1 drugs such as semaglutide also have anti-inflammatory effects which can stop lymphoedema developing at a cellular level.

Lymph nodes are tiny bean-like structures, found mainly in the neck, armpits and groin, that filter toxins, bacteria and viruses out of body fluids.

They’re one of the first places that cancer cells migrate to when the disease starts to spread.

And this is why some lymph nodes are often removed in women with breast cancer – to halt the potential spread of tumour cells.

In other cases the lymph nodes can become damaged by cancer treatments such as radiotherapy.

As a result, fluid that normally gets flushed through the lymph nodes starts to accumulate in the arms and legs – causing severe swelling and sometimes serious infections such as cellulitis (which affects the skin and the tissues just beneath).

Around a third of patients with lymphoedema develop repeated cellulitis (at least once a year), which needs treating with antibiotics.

One in ten of those go on to develop life-threatening sepsis, where the immune system mistakenly attacks the body’s major organs, causing potentially catastrophic organ failure.

There are no drug treatments for lymphoedema. Standard care involves compression therapy –wearing tight elastic garments or multi-layered bandages every day to try to physically squeeze the fluid out of tissues.

Ozempic and Mounjaro – as well as other weight-loss drugs known as GLP-1 receptor agonists – work in weight loss by mimicking appetite-regulating hormones produced in the gut.

But their effects go way beyond curbing appetite, says Dr Joseph Dayan, the reconstructive surgeon leading the new trial.

‘There are GLP-1 receptors all over the body, including on the muscle walls of lymph vessels,’ he says.

He adds that GLP-1 receptors appear to bind to these receptors and protect against damage from inflammation caused by the immune system’s response to illness, as well as curbing the activity of immune cells that promote scarring (which, in turn, blocks the flow of fluid).

Dr Dayan says his ‘lightbulb moment’ for using the fat-busting jabs came when one of his breast cancer patients gained 11kg (24lb) during treatment and her mild lymphoedema became severe.

‘I thought maybe losing weight would help, so I put her on semaglutide – and the lymphoedema evaporated,’ he says.

Dr Dayan is personally funding the pilot study and holds no financial interest in Novo Nordisk or Eli Lilly, the makers of Ozempic and Mounjaro respectively.

Commenting on the trial, Dr Simon Vincent, chief scientific officer at the charity Breast Cancer Now, said: ‘This is a promising study that could unlock further knowledge about how GLP-1 drugs work and whether they hold potential beyond their current use for diabetes and weight loss.

‘Some medical professionals have reported reductions in lymphoedema symptoms when people use GLP-1 drugs for weight loss, so this trial is a welcome step to gather reliable clinical evidence to show this use is safe for people with breast cancer.

‘For those who get lymphoedema, it can be uncomfortable and reduce quality of life.

‘Therapies such as massage and compression garments can help, but it’s unlikely to go away completely. Finding kind and effective treatments is a priority.’