Graft failure is a fatal complication following allogeneic stem cell transplantation where a second transplantation is usually required for salvage. We previously reported encouraging results with a novel Flu/Cy regimen. However, there are still around 20% patients developed delayed platelet recovery. We designed a modified regimen to further improve the hematopoietic reconstitution after second transplantation. This prospective, single-arm study aims to investigate the safety and efficacy of this modified regimen.

Inclusion Criteria:

• 1.Primary disease: hematological malignancies(AML, CML, MDS, lymphoma, etc.); 2.Graft failure after first allogeneic stem cell transplantation; 3.Time from the first transplantation to the second transplantation is less than 180 days; 4. Age≥14 years.

Exclusion Criteria:

• 1. Active infections; 2. Active GVHD; 3. Organ dysfunction: hepatic injury (Tbil≥2ULN), renal injury (Cr≥1.5ULN), heart injury (EF%<50% or symptomatic heart failure); 4. Eastern Cooperative Oncology Group (ECOG) score>2; 5. Expected life time<30 days; 5. Patients could not cooperate; 6. Other situations that are considered inappropriate for enrollment by the investigators,