1. Department of Medical Oncology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan;
2. Department of Medical Oncology and Hematology, Kobe University Hospital, Kobe, Japan;
3. Department of Head and Neck Medical Oncology, National Cancer Center Hospital East, Kashiwa, Japan;
4. Department of Head and Neck Oncology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan;
5. Eisai Co. Ltd., Tokyo, Japan;
6. Eisai Inc., Woodcliff Lake, NJ;