To evaluate the safety, tolerability, maximum tolerated dose, pharmacokinetics, and pharmacodynamics of the anti-FGFR2 antibody drug conjugate BAY1187982 in subjects with advanced solid tumors known to express fibroblast growth factor receptor 2 (FGFR2)

Inclusion Criteria:

• All subjects must be >/= 18 years at the first screening examination / visit
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1
• Subjects with advanced, histologically or cytologically confirmed solid tumors described to express fibroblast growth factor receptor 2 (FGFR2) that are refractory to any standard therapy
• For maximum tolerated dose (MTD) Dose Expansion: Subjects with advanced, histologically or cytologically confirmed triple-negative breast cancer who had undergone within 4 lines of systemic anti-cancer treatment and not eligible for standard therapy anymore.
• Subjects need to have evaluable disease (measurable or not measurable).
• Women of childbearing potential must have a negative pregnancy test performed within 7 days prior to the start of treatment

Exclusion Criteria:

• History of allergic reactions to monoclonal antibody therapy (or excipients in the formulation)
• Anti-cancer chemotherapy, experimental cancer therapy including clinical trial, or cancer immunotherapy within 4 weeks prior to the first dose of the investigational drug.
• Toxic effects of previous anti-cancer chemotherapy, experimental cancer therapy, or cancer immunotherapy have not normalized.
• History of symptomatic metastatic brain or meningeal tumors unless the subject is longer than 3 months from the end of definitive therapy before the first dose of the investigational drug and has clinically or radiologically no evidence of tumor growth.
• History of clinically significant cardiac disease
• Congenital coagulation abnormalities
• Subjects who are pregnant or are breast-feeding