Sym024 Monotherapy and in Combination With Sym021 in Patients With Advanced Solid Tumor Malignancies

Part 1 of this study will assess the safety and tolerability to establish the maximum tolerated dose (MTD) (or the maximum administered dose \[MAD\]) and/or the selected dose(s) of Sym024 in patients with solid tumor malignancies. Part 2 of this study will assess the safety and tolerability to establish the MTD (or the MAD) and/or the selected dose(s) of Sym024 when administered in combination with Sym021 in patients with solid tumor malignancies. Part 2a of this study will assess the safety and tolerability of Sym024 when first administered as a single agent during Cycle 1 (safety lead-in) followed by administration in combination with Sym021 during Cycle 2 and subsequent cycles. Part 3 of this study will assess the safety of Sym024 when administered alone or in combination with Sym021 in expanded cohorts of patients with solid tumor malignancies. April 2024: The above was the study design at trial start. Per protocol, implementation of a part 3 would require an amendment. However, this was never done as it was decided not to include a part 3.