Overview Abemaciclib for Patients With Retinoblastoma-Positive, Triple Negative Metastatic Breast Cancer Status: Active, not recruiting Trial end date: 2025-11-30 Target enrollment: Participant gender: Summary This research study is studying a drug called Abemaciclib as a possible treatment for have metastatic triple-negative type of breast cancer. Phase: Phase 2 Details Lead Sponsor: Dana-Farber Cancer InstituteCollaborator: Eli Lilly and Company