From Soup to MS Drug: One Fungus's Journey

Tetsuro Fujita's eureka moment about a Himalayan fungus came in 1985. As the scientist was driving over a bridge between Japan's Shikoku and Honshu islands on his way to conduct research on traditional herbal remedies, Fujita was contemplating ways to keep patients' immune systems from rejecting transplanted organs. He was particularly intrigued by the example of a parasitic fungus used in a Chinese medicinal soup. Known in Asia as "winter insect, summer plant," the Cordyceps fungus invades an insect larva during winter, feeds on it for months, and then grows out of the host by summer. Fujita suddenly realized that the fungus must be suppressing the immune system of the insect larvae on which it grew to maturity.

His research on Cordyceps at Kyoto University eventually helped Japanese drugmaker Mitsubishi Tanabe Pharma produce Gilenya, a treatment for multiple sclerosis that Novartis (NVS) licensed and began selling in the U.S. in October. UBS (UBS) says annual sales of the medicine, the first pill to treat the autoimmune disease afflicting more than 2 million people worldwide, may exceed $5 billion annually by 2018. That would rank it among the 10 best-selling drugs worldwide, based on data from researcher IMS Health. Mitsubishi Tanabe will likely book royalties equivalent to 10 percent of sales, based on the median of estimates by four analysts surveyed by Bloomberg News.