Overview Phase II Study of Single Agent Lenvatinib Status: Unknown status Trial end date: 2021-03-28 Target enrollment: Participant gender: Summary The Investigators hypothesize that single agent lenvatinib has biological activity in estrogen receptor positive breast cancer, and that the effects are more pronounced in patients with positive RET expression in the tumor. Phase: Phase 2 Details Lead Sponsor: National University Hospital, SingaporeCollaborators: Eisai Co., Ltd.Tan Tock Seng HospitalTreatments: Lenvatinib