Fulvestrant + Neratinib In Breast Cancer

* The research study procedures include screening for eligibility and study treatment including evaluations and follow up visits. * This research study involves the study drug Neratinib * The standard of care drug Fulvestrant * It is expected that about 25 people will take part in this research study. * This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational drug to learn whether the drug works in treating a specific disease. "Investigational" means that the drug is being studied. * The U.S. Food and Drug Administration (FDA) has not approved Neratinib for this specific disease but it has been approved for other uses. * The FDA has approved Fulvestrant as a treatment option for this disease. Fulvestrant is a standard of care drug that will be administered.