Approximately 76 people with high or very high risk myelodysplastic syndrome (MDS) and age ≥ 18 years are being asked to join this study.~The primary purpose of Part 1 (Safety run-in) is to rule out excessive toxicity of sabatolimab, when administered in combination with azacitidine and venetoclax. The primary purpose of the combined cohort 2 of the Safety run-in (Part 1) and Expansion (Part 2) is to evaluate efficacy of sabatolimab, when administered in combination with azacitidine and venetoclax in adult participants with high or very high risk MDS.~This study will consist of two parts:~Safety Run-in Part:~The first approximately 18 participants to join the study will be a part of the safety run-in. The first approximately 6 participants will be enrolled to the lower dose given every four weeks sabatolimab safety run-in cohort.~After these participants have completed 2 cycles of treatment a decision will be made to confirm whether the chosen combination of sabatolimab with azacitidine and venetoclax is considered safe to continue with approximately 12 participants, will be enrolled to the higher dose given every four weeks safety run-in cohort. After these participants have completed 2 cycles of treatment a decision will be made to confirm whether the chosen combination of sabatolimab with azacitidine and venetoclax is considered safe to continue with expansion part of the study.~Expansion Part:~After the safety run-in part confirms that the study treatment (higher dose of sabatolimab given every four weeks with azacitidine and venetoclax) is safe, about 58 more participants will be enrolled in the expansion part to better investigate the efficacy of the study treatment.
The purpose of the study is to find out if the new drug sabatolimab when given in combination with azacitidine and venetoclax, is safe and has beneficial effects in participants with high or very high risk myelodysplastic syndrome (MDS) who are not suitable for treatment with intensive chemotherapy or a stem-cell transplant (HSCT).