Participants with HR MDS or CMML will have EFS follow-up study visits every month if their disease has not transformed to AML and they have not started subsequent therapy. Participants with low-blast AML will have response follow-up study visits every month until they relapse from CR or meet the criteria for PD. All participants will enter OS follow-up (contacted every 3 months) when they have confirmed transformation to AML (for participants with HR MDS or CMML at enrollment) or experienced PD or relapse from CR (for participants with low-blast AML at study enrollment).