A Trial Evaluating the Efficacy of Ivonescimab in Metastatic Endocrine Refractory HR-positive HER2-negative or Triple Negative Invasive Lobular Carcinoma

Primary Objectives To evaluate the 6-month PFS of ivonescimab in endocrine-refractory HR+ HER2- or Triple Negative (TN) mILC Secondary Objectives * To evaluate the 12-month PFS and median PFS (mPFS) of ivonescimab inhibitor in endocrine-refractory HR+ HER2- and TN mILC * To evaluate the overall response rate (ORR) of ivonescimab in endocrine-refractory HR+ HER2- and TN mILC * To assess the disease control rate (DCR), duration of response (DOR) and overall survival (OS) * To evaluate the safety and tolerability of ivonescimab, as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events v5.0. Exploratory Objectives: * Correlate the response to ivonescimab with the molecular functional portrait (MFP) by BostonGene testing. * Explore changes in circulating tumor DNA (ctDNA) levels between baseline, D15, every restaging (including at progression) and correlate their ability to predict response to ivonescimab * Explore whole exome sequencing (WES) at baseline to identify biomarkers predictive of response to ivonescimab * Explore RNA sequencing (RNAseq) at baseline to identify biomarkers predictive of response to ivonescimab and to evaluate treatment-induced molecular changes * Develop a predictive responder score to identify participants which will benefit from ivonescimab.