Wyeth has entered an agreement to purchase the global rights to develop and market an experimental pain medication from Mochida Pharmaceutical Co. Ltd., the Japanese company said on Wednesday. Financial terms were not disclosed. The drug candidate, a new class of pain medications called TRPV1 antagonists, is in preclinical trials and is being developed to treat severe pain. Mochida will receive a one-time payment from Wyeth, as well as success-based development milestone payments. Mochida...