View clinical trials related to Unresectable Breast Cancer.
Filter by:The researchers are doing this study to find out whether the study drug onapristone ER, combined with the standard treatment for your cancer (letrozole and palbociclib), is a safe treatment for people who have metastatic or unresectable ER+/PR+/HER2- breast cancer. The researchers will test different doses of the study drug to find the highest dose that causes few or mild side effects.