Quick search about metastatic breast cancer shows https://www.breastcancertrials.org/bct_nation/browse_trials.seam https://metastatictrialtalk.org/new-metastatic-breast-cancer-trials/new-stage-4-breast-cancer-clinical-trials-sept-2020/ https://ichgcp.net/clinical-trials-registry/research/list?cond=er-positive%20her2-negative%20breast%20cancer https://clinicaltrials.gov/ct2/show/NCT04567420 Although it may only be for Stage II-III