Patients with relapsed/refractory adult acute lymphoblastic leukemia (ALL)have a very dismal prognosis. In this case, allogeneic transplantation is the only curative treatment when patient have obtained a second complete remission (CR. In France, in patients younger than 60 years old,the HyperCVAD regimen used by the MDAnderson in Houston is generally applied. In older patients (>=60 years)or young patients <= 60 years no eligible for intense chemotherapy, a combination of vincristine + Dexamethasone is generally chosen in order to avoid too much toxicity but the result is worse in term of CR.