29.03.2024

Thalidomide IS safe… but only for treating rare blood vessel condition

Thalidomide could save the lives of patients battling a rare blood vessel condition, research suggests. The notorious drug killed and injured up to 100,000 babies in the 1950s and left thousands severely disabled, damaging their limbs, ears and eyes. 

But it offers a ‘breakthrough’ in the treatment of severe arteriovenous malformations (AVMs) — abnormal tangles of blood vessels, scientists now say.

The condition, which can occur anywhere in the body, can prove excruciating, cause bleeding and even trigger strokes.

Current treatment options include surgery to remove the tangled vessels and injections that block blood from flowing through them.

Thalidomide hailed as a ‘wonder drug’ for morning sickness after it was created by German pharmaceutical giant Gruenenthal Group in the 1950s. But it was blamed for the deaths of 100,000 babies and left 10,000 severely disabled — such as with missing or deformed limbs — by the time it was withdrawn in 1961

HOW THE THALIDOMIDE SCANDAL UNFOLDED

1953: Drug created in Germany by the Gruenenthal Group

1958: Thalidomide is first licensed for use in the UK

1961: Australian doctor William McBride reports an increase in deformed babies being born at his hospital to mothers who had taken thalidomide. Drug is withdrawn later that year

1968: UK manufacturers Distillers Biochemicals Limited (now Diageo) reaches compensation settlement following a legal battle by affected families

2005: Diageo doubles its compensation payouts from £2.8m to about £6.5m a year

2008: The drug is approved for the treatment of multiple myeloma — bone marrow cancer — by the European Medicines Agency

2009: UK government agrees a £20m grant, to be paid to the Thalidomide Trust over three years

2010: Health minister Mike O’Brien makes a formal apology to thalidomide victims on behalf of the government

Thalidomide was hailed as a ‘wonder drug’ for morning sickness when it was created by German pharmaceutical giant Gruenenthal Group in the 1950s.

But it was soon pulled after a doctor in Australia reported a link between the drug and birth defects, such as malformed hands, facial disfigurement and brain damage.

Charities blame the drug for the deaths of up to 100,000 babies worldwide, and say it left 10,000 severely disabled — such as with missing or deformed limbs.

Experiments later revealed that it triggered birth defects by stopping blood vessels forming in babies.

The same mechanism is why it works in treating AVM, according to the Belgian researchers who made the discovery.

Results showed that pain reduced among all participants, their bleeding stopped and ulcers healed.

Study author Professor Miikka Vikkula said: ‘The results are convincing, and we hope that they will be confirmed by larger trials.

‘We had hypothesised that thalidomide should work in these patients, so our results did not come as a surprise.

‘But it was great to have clinical confirmation that we were right.

Professor Vikkula, of the de Duve Institute, added: ‘In our view, this is a breakthrough finding.’

Around 14 people per million suffer from AVM, which is through to be triggered by an error in blood vessel formation in early pregnancy.

If the tangled vessels are near the skin, the condition can cause blue, purple or red discoloration and swelling. The skin can also be sensitive and prone to developing ulcers.

AVM patients’ hearts have to work harder to keep up with extra blood flow, which can lead to heart problems.

People who have small AVMs do not need treatment but others may need surgery to remove the tangles.

Other treatment options include embolisation — an injection which destroys blood vessels. It is not always effective, however.

While most AVM patients live relatively normal lives, there is a risk that the abnormal tangles can burst and trigger a stroke.

The complication affects 1 per cent of patients every year.

Earlier research by the Belgian team found that AVM is caused by mutations in cells located in the walls of blood vessels, which encourage abnormal formations.

Professor Vikkula said the discovery ‘led us to wonder about the possibility of using thalidomide to inhibit’ their creation.

Around 14 people per million suffer from AVM, which is through to be triggered by an error in blood vessel formation in early pregnancy. If the tangled vessels are near the skin, the condition can cause blue, purple or red discoloration and swelling. The skin can also be sensitive and prone to developing ulcers. AVM patients’ hearts have to work harder to keep up with extra blood flow, which can lead to heart problems. People who have small AVMs do not need treatment but others may need surgery to remove the tangles

Thalidomide interferes with a protein, called the vascular endothelial growth factor, that encourages new blood vessels to grow.

AVM patients have high levels of the protein, which is thought to encourage tangles in their vessels.

Eighteen patients, aged 19 to 70, were involved in the study, which will be presented at a medical conference this week.

Participants took either 50mg, 100mg or 200mg of thalidomide per day for between two months and four years.

They were all monitored for four-and-a-half years after they stopped taking the drug.

Patients also agreed to use contraception for at least one month before starting the study and for four weeks after the end of the trial, with men having to promise to wear condoms during sex.

The results, already published in the journal Nature Cardiovascular Research, show all patients experienced a rapid reduction in pain, their bleeding stopped and ulcers healed.

Patients with heart failure recovered and one ‘appeared to be completely cured’, the researchers said.

The team also found that when patients took thalidomide and underwent injection treatment embolisation, they could have their dosage cut from 100mg or 200mg to 50mg.

Dropping the dosage reduced side effects, such as fatigue and numb limbs.

Eight patients also had stable AVMs five-and-a-half years after the study.

The researchers noted that the cost of treating AVM patients with thalidomide is up to 12 times cheaper than other drugs being tested for the condition.

The research will be presented at the annual conference of the European Society for Human Genetics in Vienna on Sunday.

Professor Alexandre Reymond, chair of the conference, said: ‘This study shows not only the healthcare and economic benefits of repurposing drugs — even the most maligned — but also how genetic research can lead to real breakthroughs in therapies for difficult to treat, distressing conditions.’

Despite being pulled for morning sickness in 1961, thalidomide is still used to this day. However, there are strict rules on women of child-bearing age using the drug.

It is given to patients with myeloma, a type of cancer that starts in the bone marrow, and for the treatment of Hansen’s disease (also known as leprosy), which is an infection caused by slow-growing bacteria.

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