Patient description: The patient is a 57-year-old man with abdominal pain and vomiting. The pain started gradually about 20 hours ago in the epigastric and periumbilical regions, radiating to his back. He drinks around 60 units of alcohol per week and smokes 22 cigarettes per day. He is healthy with no history of allergies or using any medications. His family history is positive for type 2 diabetes (his father and sister). He lives alone and has no children. The abdomen is tender and soft. His bowel sounds are normal. His heart rate is 115/min and blood pressure 110/75 mmHg. The lab results are remarkable for leukocytosis (19.5), urea of 8.5, high CRP (145), high amylase (1200) and Glc level of 15. Cross-sectional imaging was negative for obstructive pancreatitis.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Myelodysplastic Syndromes Completion of the treatment period in the base study A536-03 (ClinicalTrials.gov Identifier: NCT01749514) Adequate birth control measures Patient is able to adhere to the study visit schedule, understand and comply with all protocol requirements Patient understands and is able to provide written informed consent. In addition, patients with treatment interruption (defined as patients who complete their end-of-study visit in A536-03 and cannot directly roll over to A536-05) must also meet the following Documented diagnosis of idiopathic/de novo MDS or non-proliferative chronic myelomonocytic leukemia (CMML) according to the World Health Organization (WHO) 2 (white blood count (WBC) < 13,000/μL) that meets International Prognostic Scoring System (IPSS) classification (Appendix 2) of low or intermediate-1 risk disease as determined by microscopic and standard cytogenetic analyses of the bone marrow and peripheral complete blood count (CBC) obtained during screening Anemia defined as Mean hemoglobin concentration < 10.0 g/dL of 2 measurements (one performed within one day prior to Cycle 1 Day 1 and the other performed 7-28 days prior to Cycle 1 Day 1), for non-transfusion dependent (NTD) patients (defined as having received ˂ 4 units of red blood cells (RBCs) within 8 weeks prior to Cycle 1 Day 1), OR Transfusion Dependent (TD), defined as having received ≥ 4 units of RBCs within 8 weeks prior to Cycle 1 Day 1 Platelet count ≥ 30 x 109/L Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 (if related to anemia)  Discontinuation/withdrawal from the base study A536-03 (due to patient request, patient unwillingness or inability to comply with the protocol, pregnancy, use of prohibited medication [e.g. azacitidine], medical reason or adverse event (AE), hypersensitivity reaction to the study drug, at the discretion of the sponsor, or loss to follow-up) prior to completion of the treatment period Prior treatment with azacitidine or decitabine Treatment within 28 days prior to Cycle 1 Day 1 with an erythropoiesis-stimulating agent (ESA) Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF) Lenalidomide Iron chelation therapy if initiated within 56 days prior to Cycle 1 Day 1 Treatment with another investigational drug (including sotatercept [ACE-011]) or device, or approved therapy for investigational use ≤ 28 days prior to Cycle 1 Day 1, or if the half-life of the previous investigational product is known, within 5 times the half-life prior to Cycle 1 Day 1, whichever is longer Major surgery within 28 days prior to Cycle 1 Day 1. Patients must have completely recovered from any previous surgery prior to Cycle 1 Day 1 Known positive for human immunodeficiency virus (HIV), active infectious hepatitis B (HBV) or active infectious hepatitis C (HCV)