Notorious drug could help prevent hemorrhages and strokes

By Mark Waghorn via SWNS

The notorious drug thalidomide could prevent hemorrhages and strokes, according to new research.

Patients with diseased vessels that lead to bleeding benefited from doses taken as part of a study.

All 18 volunteers experienced dramatic reductions in symptoms and improvements in quality of life, with one being completely cured.

It could revolutionize the treatment of arteriovenous malformation (AVM), which affects more than three million people around the world.

The genetic disorder causes swelling and disfigurement - and usually worsens over time.

Lead author Professor Miikka Vikkula, of the Catholic University of Louvain, Brussels, said: "All the patients experienced a rapid reduction of pain, together with the cessation of bleeding and the healing of ulcers where these were present.

"The three patients with cardiac failure also saw their problems resolved, and one AVM appeared to be completely cured after 19 months of thalidomide and an eight-year follow-up."

He added: "We know thalidomide acts through vascular endothelial growth factor (VEGF), a signaling protein that promotes the growth of new blood vessels.

"VEGF levels are high in vascular abnormalities such as AVMs and is therefore likely that thalidomide reduces signaling via blood vessel formation promoting pathways.

"Although our study is only small, the results are convincing, and we hope they will be confirmed by larger trials."

Thalidomide is one of the most controversial drugs ever produced. In the late 1950s and early 1960s it was given to pregnant women to combat morning sickness.

Babies ended up being born without limbs. The drug was later found to inhibit development of vessels in the womb and was banned worldwide.

But the same properties, known as anti-angiogenesis, are now attracting interest in other fields.

Two other drugs recently developed for use in cancer and being tested to treat AVM cost up to twelve times as much - as well as having numerous side effects.

Prof Vikkula said: "We had hypothesized 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.

"In our view, this is a breakthrough finding and provides a solid basis for the development of molecular treatments for AVM."

The clinical trial was reported at a meeting of the European Society for Human Genetics in Vienna. It followed successful experiments on mice.

Prof Vikkula said: "Our group has been studying the causes of vascular abnormalities for 30 years.

"We have identified several genetic causes and have been able to show that certain mutations activate the signalling inside the blood vessel wall-cells and this promotes the abnormal formation of blood vessels.

"This led us to wonder about the possibility of using thalidomide to inhibit abnormal blood vessel formation."

The volunteers aged 19 to 70 had severe malformations that could not be treated by conventional approaches.

They had to agree to use contraception for at least four weeks before starting thalidomide and to continue for four weeks after the cessation of treatment.

Since thalidomide is present in semen, men also had to agree to use condoms during sex.

Patients received either 50, 100 or 200mg per day for between two and 52 months. Eight cases were stable after average treatment cessation of four and a half years.

Combined treatment with embolization, where arteries or veins within the AVM are blocked by an agent that destroys vascular wall cells, allowed the thalidomide dose to be reduced to 50mg per day in five patients.

Reducing the dose where possible was important because a higher dose was associated with side effects, particularly tiredness, damage to nerves near the brain and spinal cord and weakness and numbness in the hands and feet.

Conference chair Prof Alexandre Reymond 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."

The results are also in Nature Cardiovascular Research. AVMs are abnormal tangles of vessels connecting arteries and veins that alter normal blood flow.

They are very painful and cause bleeding and deformation of the affected body part as well as cardiac problems.

Usually congenital, they are often only noticeable in adolescence or adulthood as the person grows.

Treatment of severe cases is usually through surgery or embolisation. They can burst. About one in every hundred patients suffers a stroke each year.

Thalidomide is now being used to treat leprosy and other skin conditions - and even some cancers.