Clinigen Group plc, of Burton Upon Trent, U.K., said its subsidiary, Clinigen K.K., and GC Pharma Corp., of Yongin, South Korea, signed an exclusive licensing agreement in Japan to commercialize Hunterase (Idursulfase-beta) ICV, a human recombinant iduronate-2-sulfatase used in enzyme replacement therapy for the treatment of Hunter syndrome.