Three scientists win Nobel for anti-parasite drugs
By Tania Rabesandratana
The announcement earlier today in Sweden rewards research carried out in China, Japan and the United States in the 1960s and 1970s that “revolutionised the treatment of some of the most devastating parasitic diseases”.
William Campbell and Satoshi Ōmura discovered avermectin, a drug used to treat diseases caused by roundworm parasites, such as river blindness and elephantiasis (lymphatic filariasis). Tu Youyou discovered artemisinin, a malaria drug derived from a plant used in traditional Chinese medicine.
“After decades of limited progress in developing durable therapies for parasitic diseases, the discoveries by this year’s laureates radically changed the situation.”
Nobel Assembly at the Karolinska Institute
“After decades of limited progress in developing durable therapies for parasitic diseases, the discoveries by this year’s laureates radically changed the situation,” says the Nobel Assembly at the Karolinska Institute, which selects Nobel Prize winners in physiology or medicine. “By allowing children to go to school and adults to go to work, the treatments help them to escape poverty, which also contributes to economic growth of the community,” assembly member Hans Forssberg told reporters.
Manica Balasegaram, executive director of the Access Campaign run by Médecins Sans Frontières, which aims to widen the availability of drugs, tests and vaccines, praises the recognition of research into “often-forgotten diseases”. He says the drugs have saved millions of lives in neglected rural populations in developing countries.
Searching for useful compounds, Ōmura, a Japanese microbiologist, isolated 50 strains of Streptomyces bacteria from soil samples, using pioneering methods to grow and study the bacteria on a large scale. Campbell, an Irish parasitologist working in the United States, showed that one of the cultures killed parasites in animals, and purified the active compound, called avermectin. “Treatment with avermectin has [since] become so successful that river blindness and elephantiasis are on the verge of eradication,” says Forssberg.
Meanwhile, Chinese pharmacologist Tu screened traditional remedies in search of a potential malaria drug. Using ancient medicine books, she identified and purified artemisinin from the Artemisia plant. However, at the press briefing today, Nobel assembly members insisted the prize does not reward traditional Chinese medicine, but instead “a person who was inspired by traditional medicine” to make a modern drug.
“Nature is a source of a dazzling array of chemicals, some with marvellous properties,” says Colin Sutherland, a parasitologist at the London School of Hygiene & Tropical Medicine in the United Kingdom. But the discovery of artemisinin was not recognised outside of China until the 1990s, he says. “It takes a long time for government policies to change and for stocks to be generated, so only in the last few years have African countries been able to roll out this drug” on a large scale, he explains.
Sutherland says he is pleased the prize recognises scientists fighting diseases that affect people with poor access to good healthcare. But there is still a lot of work to be done to find the next generation of drugs, he adds.
There are already “worrying signs” of artemisinin-resistant malaria, says Balasegaram, warning that “the current research and development system, overwhelmingly based on high prices in high-income markets, is not able to deliver such treatments”. The Nobel Prize “needs to be seen as a call to action” to put more money and effort into research to develop better treatments for neglected patients in developing countries, he adds.