First-in-human Study of BAY2287411 Injection, a Thorium-227 Labeled Antibody-chelator Conjugate, in Patients With Tumors Known to Express Mesothelin

Inclusion Criteria:

* Signed informed consent
* Male or female subjects ≥ 18 years of age
* ECOG PS (Eastern Cooperative Oncology Group Performance Status) of 0 or 1
* Patients with advanced malignant epithelioid mesothelioma or advanced recurrent serous ovarian cancer, who have exhausted available therapeutic options; in addition, in the dose expansion part of the study, patients with metastatic pancreatic adenocarcinoma, who have exhausted available therapeutic options
* Availability of fresh or archival tumor tissue samples
* Adequate bone marrow, liver and renal function, as assessed by pre-defined laboratory requirements (within 28 days before start of study drug treatment)
* A negative serum pregnancy test in women of childbearing potential (WOCBP) performed within 7 days before the start of study drug administration. Women and men of reproductive potential must agree to use highly effective methods of contraception, when sexually active.

Exclusion Criteria:

* Impaired cardiac function, clinically significant cardiac disease or cardiac arrhythmias
* Pericarditis (any CTCAE grade) or pericardial effusion (CTCAE Grade ≥ 2)
* Left Ventricular Ejection Fraction (LVEF) \< 50% (as measured at screening by echocardiogram).
* History of anaphylactic reactions to monoclonal antibody therapy
* History of Myelodysplastic syndrome (MDS)/treatment-related acute myeloid leukemia (t-AML) or with features suggestive of MDS/AML
* Infections of CTCAE (Common Terminology Criteria for Adverse Events) version 5.0 Grade 2 not responding to therapy or active clinically serious infections of CTCAE Grade \>2; known human immunodeficiency virus (HIV) infection; active hepatitis B virus (HBV) or hepatitis C virus (HCV)infection requiring treatment. Patients with chronic HBV or HCV infection are eligible at the investigator's discretion provided that the disease is stable and sufficiently controlled under treatment
* Known brain, spinal or meningeal metastases