First-in-human (FIH) Trial of GEN3018 in Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML) or Higher-risk Myelodysplastic Syndrome (HR-MDS)

Key Inclusion Criteria: All Participants: * Be at least 18 years of age at the time of signing informed consent form (ICF). * Participant's life expectancy at screening is judged to be at least 3 months. * Must have fresh bone marrow samples collected at screening. * Bone marrow (BM) blasts ≥ 5% at screening. * Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of ≤ 2. * Has acceptable laboratory test results during the screening period Participants with R/R AML: * Relapsed or refractory AML, either de novo or secondary, and must have failed all conventional therapies. * Relapsed or refractory to at least one prior line of therapy. Participants with R/R HR-MDS: * Diagnosed with high- or very-high risk MDS according to International Prognostic Scoring System (IPSS-R) (score of \> 4.5 ie, high or very high) or World Health Organization (WHO) 2022 classification (ie, MDS-IB1 or MDS-IB2). * Refractory or relapsed after hypomethylating agents (HMAs) (such as azacitidine or decitabine). Key Exclusion Criteria: All Participants: * Diagnosis of acute promyelocytic leukemia (APL). * Presence of extramedullary AML at screening. * Prior autologous or allogenic hematopoietic stem cell transplant (HSCT) within 3 months prior to initiation of trial treatment. * Active graft-versus-host disease. * History of severe immune-related adverse events. * Treatment with anti-cancer agent (eg, small molecule, antibody, chemotherapy, radiation therapy), or major surgery within 2 weeks prior to the first dose of GEN3018. Other protocol-defined Inclusion and Exclusion criteria may apply.