Inclusion Criteria:

          -  Patients with cytologically confirmed and documented de novo, secondary or
             therapy-related AML, excluding acute promyelocytic leukaemia with relapsed or
             refractory disease without established alternative therapy. Or patients with
             measurable confirmed Multiple Myeloma (IMWG) with relapsed or refractory disease who
             have previously received at least three lines of treatment and without established
             alternative therapy. Or patients with histologically and measurable confirmed Non
             Hodgkin Lymphoma defined as Diffuse Large B cell Lymphoma (DLBCL), Follicular Lymphoma
             (FL), Mantle Cell Lymphoma (MCL), Marginal Zone Lymphoma (MZL), High-Grade B cell
             Lymphoma with relapsed or refractory disease who have received at least two lines of
             therapy (including rituximab) and without established alternative therapy. Or patients
             with Chronic Lymphocytic Leukemia (CLL) who have relapsed or are refractory (except
             treatment failure), as defined per iwCLL, from venetoclax treatment and without
             established alternative therapy.

          -  ECOG (Eastern Cooperative Oncology Group) performance status ≤ 2.

          -  For NHL, MM patients and CLL patients: haematological function (independent of any
             growth factor support) based on the last assessment performed before inclusion,
             defined as: absolute neutrophil count (ANC) ≥ 1 x 109/L, haemoglobin ≥ 8 g/dL,
             platelet count ≥ 50 x 109/L for NHL and MM patients, platelet count ≥ 30 x 109/L for
             CLL patients.

          -  For AML patients: circulating Blood White Cell count (WBC count) < 25 x 109/L (with or
             without use of hydroxycarbamide) based on the last assessment performed before
             inclusion.

          -  Adequate renal function based on the last assessment performed before inclusion,
             assessed as Glomerular Filtration Rate (GFR) using Modification of Diet in Renal
             Disease (MDRD) Formula.

          -  Adequate hepatic function based on the last assessment performed before inclusion.

        Exclusion Criteria:

          -  Pregnancy, breastfeeding or possibility of becoming pregnant during the study.

          -  Participation in another interventional study at the same time or another
             interventional study requiring investigational treatment intake within 3 weeks or at
             least 5 half-lives (whichever is longer) prior to the first S65487 administration.

          -  Participant already enrolled in the study (informed consent signed) and has received
             at least one dose of S65487.

          -  Patients who have not recovered from toxicity of previous anticancer therapy,
             including grade ≥ 2 non-hematologic toxicity, prior to the first IMP administration
             (including peripheral neurotoxicity). Certain toxicities will not be considered in
             this category (e.g. alopecia).

          -  Patients refractory to a previous treatment with a Bcl-2 inhibitor.

          -  For AML patients : Allogenic stem cell transplant within 3 months before the first IMP
             administration and/or patients who still receive immunosuppressive treatment within 3
             months before the first IMP administration and/or patients with active
             Graft-versus-host disease within 3 months before the first IMP administration and/or
             patient who receive donor lymphocyte infusion (DLI) within 3 months before the first
             IMP administration.

          -  For NHL, MM and CLL patients : Prior allogenic stem cell transplant before the first
             IMP administration and/or Autologous stem cell transplant within 3 months before the
             first IMP administration.