A Study Evaluating Venetoclax in Combination With Azacitidine in Participants With Treatment-Naïve Higher-Risk Myelodysplastic Syndromes (MDS)

Prior treatment

• Participant has received prior therapy for MDS. (Prior supportive care in form of transfusions or growth factors, etc., is not considered prior therapy).
• Participant has received prior therapy with a BCL-2 Homology 3 (BH3) mimetic.
• Participant has a diagnosis other than previously untreated de novo MDS (as defined in the protocol) including:
  • MDS with IPSS risk categories Low or Int-1 (overall IPSS score \< 1.5)
  • Therapy-related MDS (t-MDS).
  • MDS evolving from a pre-existing myeloproliferative neoplasm (MPN).
  • MDS/MPN including chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (CML), juvenile myelomonocytic leukemia (JMML) and unclassifiable MDS/MPN.
• Participant has received allogeneic Hematopoietic Stem Cell Transplantation (HSCT) or solid organ transplantation.
• Participant has received a live attenuated vaccine within 4 weeks prior to the first dose of study drug.

• Participant must have documented diagnosis of untreated de novo MDS with:
  • International Prognostic Scoring System (IPSS) risk categories Int-2 or High (minimum IPSS overall score of 1.5) OR Revised IPSS (IPSS-R) categories intermediate, high or very high (score of \> 3) and
  • Presence of less than 20% bone marrow blasts per bone marrow biopsy/aspirate.
• Eastern Cooperative Oncology Group (ECOG) performance score of less than or equal to 2.