Inclusion Criteria:  Aged from 3 to 70 years All hematological diseases Suffering from primary or secondary (within the 60 days post-transplantation) graft failure after a 1st allo-SCT  With usual criteria for allo-SCT:  ECOG ≤ 2 No severe and uncontrolled infection Cardiac function compatible with high dose of cyclophosphamide Adequate organ function: ASAT and ALAT ≤ 2.5N, total bilirubin ≤ 2N, creatinine clearance ≥30ml / min With identification of a haploidentical donor (brother, sister, parents, adult children or cousin) Absence of donor specific antibody (DSA) detected in the patient with a MFI ≥ 1500 (antibodies directed towards the distinct haplotype between donor and recipient) With health insurance coverage (bénéficiaire ou ayant droit). Understand informed consent or optimal treatment and follow-up. Contraception methods must be prescribed during all the duration of the research. Women and men of childbearing age must use contraceptive methods within 12 months and 6 months after the last dose of cyclophosphamide, respectively. Having signed a written informed consent (2 parents for patients aged less than 18)  Exclusion Criteria:  Aged< 3 years old and >70 years old With uncontrolled infection With Seropositivity for HIV or HTLV-1 or active hepatitis B or C defined by a positive PCR HBV or HCV and associated hepatic cytolysis Yellow fever vaccine within 2 months before transplantation Cancer in the last 5 years (except basal cell carcinoma of the skin or "in situ" carcinoma of the cervix) Uncontrolled coronary insufficiency, recent myocardial infarction <6 month, current manifestations of heart failure, uncontrolled cardiac rhythm disorders, ventricular ejection fraction <50% Heart failure according to NYHA (II or more) Preexisting acute hemorrhagic cystitis Renal failure with creatinine clearance < 30ml / min Urinary tract obstruction Pregnant (β-HCG positive) or breast-feeding Who have any debilitating medical or psychiatric illness, which preclude understanding the inform consent as well as optimal treatment and follow-up COVID vaccination or recent COVID disease <3 months Tutorship or curatorship Contraindications to treatments used during the research