Phase II Study on Stopping CDK46 Inhibitors in Women with Metastatic HR Positive, HER2 Negative Breast Cancer Showing Stable Disease

What this Trial Is About

Researchers are investigating the effects of stopping CDK46 inhibitors in women with metastatic hormone receptor HR positive, HER2 negative breast cancer who have maintained disease control after long-term treatment. This phase II trial aims to evaluate whether disease stability continues when CDK46 inhibitors are discontinued after at least 12 months of combined treatment with endocrine therapy. The study is open-label, randomized, and conducted at multiple centers. Participants are randomly assigned to one of two groups one group continues both CDK46 inhibitor treatment such as Palbociclib or Abemaciclib and endocrine therapy, while the other group discontinues the CDK46 inhibitor but continues endocrine therapy alone. The study monitors disease progression and treatment effects over time, with a focus on how long patients remain free from disease worsening after stopping the CDK46 inhibitor. During the study, participants will be regularly assessed for disease progression, safety, and quality of life using questionnaires and clinical evaluations. Researchers will measure progression-free survival at 12 months and up to 54 months, time to treatment failure, time to first chemotherapy use, and monitor adverse events. The total participation duration may extend beyond four years, with ongoing evaluations to understand long-term outcomes and safety after stopping the CDK46 inhibitor.

Discontinuation of CDK4/6 Inhibitors in Patients With Metastatic HR Positive, HER2 Negative Breast Cancer