Parasitic Disease Drug Researchers Awarded Nobel Prize

The 2015 Nobel Prize in Physiology or Medicine has been awarded three researchers for the development of therapies “that have revolutionized the treatment of some of the most devastating parasitic diseases,” the Nobel organization reports in a press announcement.

William C. Campbell and Satoshi Ōmura were jointly recognizers for their discoveries concerning a novel therapy against infections caused by roundworm parasites. Youyou Tu was recognized for her discoveries concerning a novel therapy against malaria diseases caused by parasites.

Campbell and Ōmura discovered the drug, avermectin, the derivatives of which have lowered the incidence of river blindness and lymphatic filariasis, and have shown efficacy against an expanding number of other parasitic diseases. Tu discovered artemisinin, a drug that has significantly reduced the mortality rates for patients suffering from malaria.

Ōmura, a Japanese microbiologist and expert in isolating natural products, focused on a group of bacteria, streptomyces, which lives in the soil and was known to produce a plethora of agents with antibacterial activities. Ōmura isolated new strains of streptomyces from soil samples and successfully cultured them in the laboratory. From many thousand different cultures, he selected about 50 of the most promising, with the intent that they would be further analyzed for their activity against harmful microorganisms

Campbell, a US-based expert in parasite biology, acquired Ōmura’s streptomyces cultures, explored their efficacy, and showed that a component from one of the cultures was efficient against parasites in domestic and farm animals. The bioactive agent was purified and named avermectin, which was subsequently chemically modified to a compound called Ivermectin. Ivermectin was later tested in humans with parasitic infections and effectively killed parasite larvae (microfilaria). Collectively, Ōmura and Campbell’s contributions led to the discovery of a new class of drugs with extraordinary efficacy against parasitic diseases, the Nobel organization reports.

In the late 1960’s Youyou Tu in China turned to traditional herbal medicine to tackle the challenge of developing novel malaria therapies as traditional chloroquine treatments had declining success. From a large-scale screen of herbal remedies in malaria-infected animals, an extract from the plant Artemisia annua emerged as a candidate. Results were inconsistent; Tu reviewed ancient literature and discovered clues to successfully extract the active component from Artemisia annua. She was the first to show that this component, later called artemisinin, was highly effective against the Malaria parasite, both in infected animals and in humans.

Campbell received a bachelor’s degree from Trinity College, University of Dublin, Ireland in 1952, he received a doctorate from University of Wisconsin, Madison, WI, in 1957. From 1957–1990 he worked at the Merck Institute for Therapeutic Research. Campbell is currently a Research Fellow Emeritus at Drew University, Madison, NJ.

Ōmura received a doctorate in Pharmaceutical Sciences in 1968 from University of Tokyo, Japan and a doctorate in Chemistry in 1970 from Tokyo University of Science. He was a researcher at the Kitasato Institute, Japan from 1965–1971 and Professor at Kitasato University, Japan from 1975–-2007. Since 2007, Satoshi Ōmura has been Professor Emeritus at Kitasato University.

Tu graduated from the Pharmacy Department at Beijing Medical University in 1955. Since 1965, she has worked at the China Academy of Traditional Chinese Medicine, as assistant professor, associate professor, professor, and chief professor at the China Academy of Traditional Chinese Medicine.

Source: Nobel Assembly at Karolinska Institute