The major changes to the protocol include the addition of a requirement for informed consent from donors of patients randomized to the CD34 selection arm (the protocol document only includes the informed consent for related donors, while the NMDP will have purview over consenting the unrelated donors); a modification to the way that chemotherapy doses are calculated; exclusion of modifications to the conditioning regimens in Arms A and B and of modifications to MTX regimens; addition of information regarding data submission and adverse event reporting; addition of information about ethics and regulatory requirements and procedures; addition of risks for rATG and risk language for lymphoproliferative syndrome as well as Mesna.

Major changes to the Protocol include: 1. Inclusion criteria for patients with CMML were added as follows: “Patients with CMML must have a WBC count ≤ 10,000 cells/μL and < 5% blasts in the marrow.” 2. FLT3 and other tyrosine kinase inhibitors for post-transplant maintenance and for prevention of disease relapse are now allowed. 3. The fourth dose of Mesna may now be infused 8-9 hours after the completion of cyclophosphamide. 4. Toxoplasmosis NAAT for patients on the CD34+ arm considered at risk for infection/reactivation has been replaced with placing such patients on prophylactic agents. 5. The window from randomization to initiation of conditioning has been removed. 6. After randomization of MDS patients, the bone marrow assessment must be repeated if it did not occur within 6 weeks prior to the initiation of the transplant conditioning regimen. Patient Informed Consent: 1. Weekly monitoring of toxoplasmosis until Day 100 then at each clinical assessment until Day 180 was removed from §Health Evaluations After the Transplant, as for NAAT for toxoplasmosis were removed from the protocol. 2. The volume of optional blood samples to be collected after transplant was corrected from 80mL to 86mL as required by Table 1 of Appendix C, Laboratory Procedures. Donor Informed Consent: 1. Language was updated to limit confusion with regards to charges for the cell manipulation procedure. The selection procedure will be paid for, for this study. 2. Clarification was provided to explain that the investigational device that is part of the cell selection system that will be used to remove T cells from your stem cell donation, called stem cell manipulation, prior to transplantation. 3. The costs section was updated to reflect that the patient will need to pay for the cell selection procedure and that the donor will not be charged for the selection procedure.

Major changes to the Protocol include: Clarification of the definition of “leukemia in complete morphologic CR with or without hematologic recovery”. Added Inclusion Criteria statement: “Patients with > 5% blasts due to a regenerating marrow must contact the protocol chairs for review.”. Clarification for sites to declare planned post-transplant maintenance therapy prior to randomization. Addition of new Exclusion Criterion: “If it is known prior to enrollment that the hematopoietic stem cell product will need to be cryopreserved, the patient should not be enrolled.”. Addition of extra day of rest in the conditioning regimens of any treatment arm when delivery of the patient’s graft is delayed. Addition of cryopreservation language. Addition of new secondary endpoint “graft failure.” Primary graft failure defined as “no neutrophil recovery to > 500 cells/μL by Day 28 post HSCT.” Secondary graft failure defined as “initial neutrophil engraftment followed by subsequent decline in absolute neutrophil counts < 500 cells/μL for > 3 days, unresponsive to growth factor therapy, but cannot be explained by disease relapse or medications.” Clarification of systemic steroid usage to “if clinically indicated”. Loosened the requirement of the pre-transplant bone marrow aspirate for MDS patients prior to randomization. The protocol still requires that it must be repeated if not within 6 weeks prior to the initiation of the transplant conditioning regimen. Addition of Adverse Device Effect Reporting requirement. Patient Informed Consent: A new “Risks and Toxicities Related to GVHD Prophylaxis” from Investigator’s Brochure v8.0 was added to the patient informed consent. A new complication from the Investigator’s Brochure v8.0 “PTLD can be fatal” was added to the “Lymphoproliferative Syndrome-other Complication section. Donor Informed Consent: New information from the Investigator’s Brochure v8.0 was added to the protocol and donor informed consent on effectiveness of the device.