S-1 is an oral pyrimidine fluoride-derived anticancer agent in which a prodrug of 5-FluoroUracil (5-FU), Tegafur, is combined with two inhibitors of enzymes to increase the amount of circulating 5-FU with less gastrointestinal toxicity.
Taiho’s propriety anticancer agent has been marketed in Japan since 1999 and is prescribed for gastric, colorectal, head and neck, non-small cell lung and inoperable or recurrent breast cancers. It is also currently being investigated in phase III trials in Europe, the US and other countries.
Under the terms of the agreement, Sanofi-Aventis will lead and fund the product’s development worldwide, except in Japan and certain other Asian countries. Sanofi-Aventis will be responsible for the commercialization of the product worldwide in the same territories and will make an upfront payment to Taiho, along with milestone payments and royalties. The upfront and milestone payments could reach $360 million.
While the addition of S-1 to Sanofi-Aventis’ pipeline is not expected to be a revolutionary or pipeline-transforming event, it is expected to help reinforce the pharmaceutical giant’s leading position in the oncology arena.