Short abstract
BBC 2, 12 February at 9 pm
Rating: ★★★
Few, if any, drugs have achieved the notoriety of thalidomide. Serendipitously discovered in 1954, thalidomide caused congenital birth defects in thousands of children, and has been one of the most cautionary tales in the history of medicine. But has its age of redemption come? Could it be the “new wonder drug” that many researchers hope?
This episode of the BBC science documentary series Horizon introduced us to Dr Chase Peterson. Dr Peterson, the programme explained, is a man who should be dead: he has the blood cancer multiple myeloma, which is usually lethal in between two and five years. After conventional treatment (chemotherapy and bone marrow transplantation) had failed, Dr Peterson tried an experimental drug that he hoped would get the cancer under control. Within two weeks of starting thalidomide the number of cancer cells had reduced, and by six weeks his blood tests were back to normal.
Not everyone is so pleased with the new lease of life for thalidomide. Kevin is one of the many people born with shortened limbs after his mother took thalidomide to treat morning sickness during pregnancy. Little was known about the drug's mechanism of action, but it had been considered safe—even in overdose. Thousands of children were born with shortened limbs following the introduction of thalidomide into routine medical practice. Only half of these children survived their first month of life.
It was not until 1961, five years after the first of these children were born, that an obstetrician made the connection between what had seemed a harmless drug in adults with the malformations that resulted if the medicine was taken in the first 60 days of pregnancy. Thalidomide's licence was withdrawn a few months later.
However, within three years thalidomide had made a comeback. A doctor in Jerusalem gave one of his leprosy patients some thalidomide that had been languishing on the shelf. He hoped that its tranquillising effect could be used to give the patient some rest. Instead, rather miraculously, the deep inflammatory skin nodules caused by his leprosy resolved overnight. A new era beckoned for the infamous drug. So how did thalidomide work? At the time, a new theory suggested that it regulated the immune system of leprosy patients. But if it did this in leprosy, maybe it could be used in other immune-mediated diseases.
Sarah Craven has Behçet's syndrome. The characteristic sores affecting her mouth and genitals used to preventing her even from sitting down or eating food. However, she told Horizon that thalidomide had helped her to regain control of her life—so much so that she became pregnant and had to stop taking the drug.
Dr Judah Falkman, who pioneered the use of thalidomide for multiple myeloma, told the programme that he believed tumours stimulated angiogenesis and he thought that thalidomide might interfere with this process. It might not be a cure, but it might control the disease.
Unlike many cancer drugs, thalidomide is now thought to have multiple actions against cancers. As well as affecting angiogenesis, it may directly attack cancer cells and activate the immune system against the disease.
But elsewhere disaster had repeated itself. By the 1970s and 1980s a new generation of thalidomide babies had been born—this time in Brazil, where leprosy had ravaged much of the population and the drug had been used widely. Some Brazilian mothers had not heeded the warnings of side effects—written in English.
Thalidomide revolutionised the way we think about drugs and their effects on the fetus. The programme makers concluded that it had now revolutionised the way we think about cancer. Cancers could become conditions that are controlled rather than cured, it said.
Horizon provided an informative update on what will always be a controversial topic, giving a good and balanced wrongs of giving the most feared of drugs a second chance.