[177Lu]Lu-NeoB in Combination With Ribociclib and Fulvestrant in Participants With ER+, HER2- and GRPR+ Advanced Breast Cancer
Trial Parameters
Brief Summary
The purpose of this trial is to estimate the recommended dose (RD) of \[177Lu\]Lu-NeoB in combination with ribociclib and fulvestrant in participants with estrogen receptor (ER) positive (ER+), human epidermal growth factor receptor-2 (HER2) negative (HER2-) and gastrin releasing peptide receptor (GRPR) positive (GRPR+) advanced breast cancer experiencing early relapse from (neo)adjuvant endocrine therapy or who have progressed on endocrine therapy in combination with a CDK4/6 inhibitor for advanced disease.
Eligibility Criteria
Key Inclusion criteria: * Adult female or male \>= 18 years of age at the time of informed consent * Histologically and/or cytologically confirmed diagnosis of estrogen-receptor positive with ER \>10% (regardless of progesterone receptor (PgR) expression) breast cancer by local laboratory testing (based on the most recently analyzed tissue sample) * HER2 negative breast cancer defined as a negative in situ hybridization test or an immunohistochemistry (IHC) status of 0, 1+ or 2+. If IHC is 2+, a negative in situ hybridization (e.g. fluorescence in situ hybridization (FISH), chromogenic in situ hybridization (CISH), or silver in situ hybridization (SISH)) test is required by local laboratory testing (based on the most recently analyzed tissue sample) * Participant has advanced (loco regionally recurrent not amenable to curative therapy (e.g. surgery and/or radiotherapy) or metastatic) breast cancer Participants may be: 1. relapsed with documented evidence of relapse on or within 12 mont