Sabatolimab as a Treatment for Patients With Acute Myeloid Leukemia and Presence of Measurable Residual Disease After Allogeneic Stem Cell Transplantation.

Inclusion Criteria:

• Signed informed consent must be obtained prior to participation in the study.

• At the date of signing the informed consent form (ICF), eligible participants mustbe ≥ 18 years for the adult cohorts; and ≥ 12 years old but < 18 years old for theadolescent cohort (cohort 5), which will open after completion of Safety Run-in.

• Participants in complete remission (< 5% bone marrow blasts, absence of circulatingblasts, and absence of extramedullary disease) with MRD positivity by localassessment or by central assessment where required (e.g., USA sites), any time at ≥Day 60 after aHSCT

• Diagnosis of AML/secondary AML and received one prior aHSCT performed to control AML

• Ability to provide a fresh bone marrow aspirate sample collected within 28 days fromenrollment/randomization, and immediately shipped to a Novartis designated centrallaboratory for MRD testing.

• Systemic GvHD (graft versus host disease) prophylaxis or treatment [immunosuppressive treatment (IST)] completely tapered for at least two weeks priorto study entry. Prednisone dose ≤ 5 mg/day or equivalent corticosteroid dose isallowed.

• Participants who are found with MRD positivity while still on or tapering systemicGvHD prophylaxis or treatment, MRD positivity must be re-confirmed at least 2 weekafter the last dose of IST

• For the adult cohorts, participants must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2.

For the adolescent cohort, participants must have a Karnofsky (age ≥ 16 years) or Lansky (age < 16 years) performance status score ≥ 50%.

Exclusion Criteria:

• Prior exposure to TIM-3 directed therapy at anytime.

• History of severe hypersensitivity reactions to any ingredient of study drug(s) (azacitidine, sabatolimab) or monoclonal antibodies (mAbs) and/or their excipients

• Active Hepatitis B (HBV) or Hepatitis C (HCV) infection. Participants whose diseaseis controlled under antiviral therapy should not be excluded.

• Active acute GvHD grade III-IV according to standard criteria (Harris 2016).

• Active moderate chronic GvHD of the lungs according to NIH consensus criteria.Active severe chronic GvHD according to NIH consensus criteria.

• History of another primary malignancy that is currently clinically significant orcurrently requires active intervention. Participants who are receiving adjuvanttherapy, such as hormone therapy, are eligible

• Any concurrent severe and/or active uncontrolled infection requiring parenteralantibacterial, antiviral or antifungal therapy (such as severe pneumonia,meningitis, or septicemia)

• Active autoimmune disease requiring systemic therapy (e.g. corticosteroids).Topical, inhaled, nasal and ophthalmic steroids are not prohibited. Replacementcorticosteroids therapy is allowed and not considered a form of systemic treatment

• Live vaccine administered within 30 days prior to the first day of study treatment (Cycle 1 Day 1)

• Other concurrent severe and/or uncontrolled medical conditions (e.g. uncontrolleddiabetes mellitus, chronic obstructive or chronic restrictive pulmonary diseaseincluding dyspnoea at rest from any cause) or history of serious organ dysfunctionor disease involving the heart, kidney, or liver

Other protocol defined inclusion/exclusion criteria may apply