One or more metastatic tumors measurable per RECIST Criteria Measurable disease as per RECIST v. criteria Must have measurable disease per RECIST v. Response Criteria INCLUSION CRITERIA FOR REGISTRATION (HER MUTATION IDENTIFIED AT AN OUTSIDE CLIA CERTIFIED LOCATION): Presence of measurable or non-measurable disease by RECIST . is acceptable, except to be eligible for the Part II fulvestrant-naive ER+ cohort, at least one measurable disease by RECIST . is required Measurable disease by RECIST . criteria Have measurable or non-measurable disease per RECIST . criteria for solid tumors and RANO criteria for HGG Measurable disease by RECIST . criteria Measurable disease as per RECIST v. criteria Have measurable disease per RECIST . criteria present Measurable disease by per RECIST . criteria; radiographic tumor assessment performed within days of registration. All patients enrolled will be required to have measurable disease by RECIST . criteria New or increasing non-bone disease (RECIST . criteria); Measurable disease by RECIST . criteria Patients must have measurable disease by RECIST criteria Have measurable disease per RECIST . criteria present Have measurable disease per RECIST . or irRECIST criteria present Measurable disease as per the RECIST criteria v . Measurable disease according to PET Response Criteria, with the exception of patients with cutaneous disease that can be measured and followed by RECIST criteria CERITINIB INCLUSION CRITERIA: Measurable disease by RECIST v. REGORAFENIB INCLUSION CRITERIA: Measurable disease by RECIST v. ENTRECTINIB INCLUSION CRITERIA: Measurable disease by RECIST v. Patients must have measurable disease by the Modified RECIST criteria Measurable disease as per RECIST . criteria. Patients must have measurable disease per RECIST . criteria; all sites of disease must be evaluated within weeks prior to randomization Measurable disease per RECIST . criteria Have measurable disease per RECIST . criteria Measurable disease by RECIST . criteria Progressive measurable disease: using conventional solid tumour criteria RECIST .. Disease must be measurable by RECIST . criteria Subjects must have measurable disease by CT or MRI per RECIST . criteria (radiographic tumor assessment performed within days of first dose of study drug) or clinically apparent disease that the investigator can follow for response per RECIST . Measurable disease per RECIST . criteria Participants must have measurable disease by RECIST . criteria Measurable disease as assessed by RECIST . criteria (Appendix A). Measurable disease as assessed by modified RECIST for MPM and by RECIST . criteria for peritoneal mesothelioma, NSCLC, uveal melanoma, HCC, glioma and sarcomatoid carcinoma Measurable disease by RECIST . criteria Measurable disease by RECIST . criteria Participants in the Phase II portion of the trial must have measurable disease by RECIST . criteria Breast cancer participants must have measurable disease by RECIST criteria For the Extension cohorts, patients must have measurable disease by RECIST criteria and meet the following disease-specific criteria: Measurable disease by RECIST . criteria. Measurable disease at screening by RECIST . criteria Measurable disease by RECIST v. criteria Measurable disease as assessed by RECIST . criteria (Appendix A). Measurable disease by RECIST . criteria Measurable disease as assessed by RECIST . criteria (Appendix A). Measurable disease on baseline imaging per RECIST . criteria Patients must have measurable disease by RECIST . criteria Measurable disease per RECIST . criteria Measurable disease by RECIST criteria Measurable disease as per RECIST v. criteria