Phase I Study of Abemaciclib with Radiation Therapy for Adults with HR, HER2- Metastatic Breast Cancer

What this Trial Is About

Researchers are evaluating different doses of abemaciclib combined with hormone therapy and radiation therapy in people diagnosed with metastatic hormone receptor-positive HR, HER2-negative breast cancer. This Phase I study aims to find the maximum tolerated dose of abemaciclib when given alongside radiation therapy to bone metastases, helping to identify the best dose for future treatments. Participants will receive abemaciclib orally every 12 hours starting on the day of radiation therapy simulation through the end of radiotherapy, which lasts up to 28 days. Radiation therapy is given as either 27 Gy in 3 daily fractions or 30 Gy in 5 daily fractions, all completed within 28 days. After determining the maximum tolerated dose, additional patients needing bone metastases palliation will be enrolled for further evaluation. During the study, participants will undergo regular assessments to monitor tolerability and side effects over a period of up to one year. Researchers will track the maximum tolerated dose of abemaciclib and evaluate patient recovery from prior treatments. Participants must have adequate organ function and be able to swallow oral medications. Safety monitoring and adherence to treatment schedules will be part of the study procedures throughout the trial duration.

A Study of Abemaciclib and Radiation Therapy in People With Metastatic Breast Cancer