DLTs: occurrence of any of following related to investigational medicinal product (IMP): Any grade (G) greater than or equal to (>=) 3 nonhematological adverse events (AE); G4 hematological toxicities (bone marrow hypocellularity, decreased neutrophils, febrile neutropenia, decreased platelet count and anemia) as defined in national cancer institute common terminology criteria for adverse events (NCI-CTCAE, v4.03); G3 or G4 cytokine release syndrome (CRS) (G1: fever, nausea, fatigue, headache, myalgias and malaise; G2: oxygen requirement less than [<] 40 percent (%); G3: oxygen requirement greater than [>] 40% ; G4: life-threatening symptoms, requirement for mechanical ventilation, organ toxicity, G5: death) graded by NCI Consensus Guidelines; Grade 2 CRS for >48 hours or <48 hours before IMP; any treatment-emergent AE of potential significance and IMP-related adverse reaction lasted >2 weeks with failure to recover to baseline or improve to Grade less than or equal to (<=1).

Analysis was performed on dose-limiting toxicities (DLT) evaluable population which included all participants in dose escalation part, who received at least 5 out of 6, weekly IV administrations of SAR440234 and participants who discontinued IMP before completion of Cycle 1 because of DLT.

In this outcome measure, number of participants with allergic reactions or hypersensitivity and CRS or acute infusion reactions is reported. CRS is a nonantigen specific toxicity that occurs as result of potent immune activation mediated by large, rapid release of cytokines into blood from immune cells affected by IMP. Grading and management of CRS was based on National Cancer Institute (NCI) Consensus Guidelines 2014. Allergic/Hypersensitivity reactions or acute infusion reactions are defined as disorder characterized by adverse local/general response from exposure to allergen; graded by NCI CTCAE v4.03.

Analysis was performed on safety population.

Response: assessed by IWG 2003 recommendations for acute myeloid leukemia (AML) and revised 2000 criteria for myelodysplastic syndrome (MDS). MDS - OR: complete remission (CR)/marrow CR/partial remission (PR), CR: repeat bone marrow show <5% myeloblasts and peripheral blood evaluations lasting >=2 months hemoglobin (>11 grams per deciliter), neutrophils 1500 per cubic millimeter (mm^3), platelets >=100000/mm^3, blasts 0% and no dysplasia, PR: all CR criteria except blasts decreased by >=50% over pretreatment or less advanced than pretreatment. AML - OR:CR/CR with incomplete hematological recovery(CRi)/PR, CR:absolute neutrophil count (ANC) >=1000 per microliter (mcL), platelets >=100000/mcL, <5% blast cells in bone marrow; auer rods should not be detectable; no platelet/whole blood transfusions for 7 days prior hematology test. CRi:all criteria of CR except platelets and/or ANC. PR:all CR criteria except blasts decreased by >=50% over pretreatment or less advanced than pretreatment.

Due to the early termination of the study, data for this outcome measure was not collected and analyzed.

DOR: time from first tumor assessment at which the overall response was recorded as CR, marrow CR, or PR (MDS) and CR/CRi (AML) until documented progressive disease (PD) determined by IWG criteria, or death from any cause, whichever occurred first. Per IWG criteria, relapse was defined as reappearance of blasts in blood or bone marrow (>5%) or in any extramedullary site after a CR. CR:<= 5% myeloblasts in bone marrow with no evidence of persistent dysplasia; peripheral blood showing hemoglobin>=11g/dL. Marrow CR: no circulating blasts, <5% blast, absolute neutrophil count >1000/mcL, platelets >100000/mcL, no recurrence for 4 weeks. CRi: meet all criteria for CR except platelet count and/or ANC. PR: all CR criteria except blasts decreased by >=50% over pretreatment or less advanced than pretreatment. Progression: at least 50% decrease from maximum remission/response in granulocytes/platelets; reduction in Hgb by >=2 g/dL; transfusion dependence.

Due to the early termination of the study, data for this outcome measure was not collected and analyzed.

Disease-free survival was defined as the time from date of first administration of study intervention until the earliest of any of the following: date of death or date of first response assessment confirming relapse or date of final response assessment which fails to confirm response whichever occurred first.

Due to the early termination of the study, data for this outcome measure was not collected and analyzed.

An AE was defined as any untoward medical occurrence in a participant who received study drug and did not necessarily had to have a causal relationship with the treatment. Serious AEs (SAEs) were any untoward medical occurrence that resulted in any of the following outcomes: death, life-threatening, required initial or prolonged in-patient hospitalization, persistent or significant disability/incapacity, congenital anomaly/birth defect, or considered as medically important event. TEAEs were defined as the AEs that developed or worsened or became serious during the TEAE period (defined as the time from the first dose of the IMP to the last dose of IMP + 30 days).

Analysis was performed on safety population.

Objective response was defined as the percentage of participants who had a marrow CR, or PR (MDS) and CR/CRi (AML) per IWG criteria. For MDS, CR: repeat bone marrow show <5% myeloblasts and peripheral blood evaluations lasting >=2 months of hemoglobin (>11 g/dL), neutrophils 1500/mm^3, platelets >=100000/mm^3, blasts 0% and no dysplasia, PR: all CR criteria except blasts decreased by >=50% over pretreatment or less advanced than pretreatment. For AML, CR: ANC >=1000/mcL, platelet count >=100000/mcL, bone marrow should contain <5% blast cells; auer rods should not be detectable; no platelet/whole blood transfusions for 7 days prior to date of hematology assessment. CRi: morphologic complete remission but ANC count might be <1000/mcL or platelet <100000/mcL.

Due to the early termination of the study, data for this outcome measure was not collected and analyzed.

ADA response categories: 1) Treatment-induced ADA: Participants without pre-existing ADA and without pre-treatment samples and who developed ADAs during the TEAE period. 2) Treatment-boosted ADA: Participant with pre-existing ADAs that was increased at least a 4-fold in titer compared to Baseline during the TEAE period. 2) Treatment-emergent ADA: Participants with at least one treatment-induced/boosted ADA sample. TEAE period was defined as the time from the first dose of the IMP to the last dose of the IMP + 30 days.

Analysis was performed on ADA population which included all participants who had given their informed consent, had received at least 1 dose (even incomplete) of SAR440234 and had at least 1 available ADA result after IMP administration.

Cmax was the maximum observed plasma concentration. Cmax was obtained by a non-compartmental analysis. Here in the time frame, Day = D, start of infusion = SOI, mid of infusion = MOI, end of infusion = EOI and hours = H.

Analyzed on PK population which included participants who had given their informed consent and had received at least one dose (even incomplete) of SAR440234 with at least 1 evaluable drug concentration after IMP administration. Here, number analyzed = participants with available data for each specified category.