Blackstone Group agreed to buy Ayumi Pharmaceutical Corp, a Japanese drug maker. Financial terms were not disclosed. Blackstone will acquire the maker of anti-rheumatism drugs from PE firm Unison Capital and medical information site business M3. “We look forward to working with the company to leverage Blackstone’s global footprint and expertise in this sector to help Ayumi meet the growing need for its RA (rheumatoid arthritis) and orthopedic products,” Atsuhiko Sakamoto, head of Blackstone’s PE business in Japan.