Deferring allogeneic transplantation for adult acute lymphoblastic leukemia: is there a second chance?

Allogeneic transplantation for Ph+ acute lymphoblastic leukemia with posttransplantation cyclophosphamide

Allogeneic blood or marrow transplantation (alloBMT) is standard of care for adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) in first complete remission (CR1). The routine pretransplant and posttransplant use of tyrosine kinase inhibitors (TKIs) has dramatically improved outcomes, but the optimal conditioning regimen, donor type, and TKI remain undefined. The bone marrow transplant database at Johns Hopkins was queried for adult patients with de novo Ph+ ALL who received alloBMT using posttransplantation cyclophosphamide (PTCy) as a component of graft-versus-host disease (GVHD) prophylaxis from 2008 to 2018. Among transplants for Ph+ ALL, 69 (85%) were performed in CR1, and 12 (15%) were performed in second or greater remission (CR2+). The majority of transplants (58%) were HLA haploidentical. Nearly all patients (91.4%) initiated TKI posttransplant. For patients in CR1, the 5-year relapse-free survival (RFS) was 66%. The use of nonmyeloablative conditioning, absence of measurable residual disease (MRD) according to flow cytometry at transplant, and the use of dasatinib vs imatinib at diagnosis were associated with improved overall survival (OS) and RFS. Neither donor type nor recipient age ≥60 years affected RFS. When analyzing all transplants, alloBMT in CR1 (vs CR2+) and the absence of pretransplant MRD were associated with improved RFS. Most relapses were associated with the emergence of kinase domain mutations. The cumulative incidence of grade 3 to 4 acute GVHD at 1 year was 9%, and moderate to severe chronic GVHD at 2 years was 8%. Nonmyeloablative alloBMT with PTCy for Ph+ ALL in an MRD-negative CR1 after initial treatment with dasatinib yields favorable outcomes.

Efficacy and safety of G-CSF, low-dose cytarabine and aclarubicin in combination with l-asparaginase, prednisone in the treatment of refractory or relapsed acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) patients who fail to acquire complete remission (CR) or who relapse after initial response have poor prognosis. At present there is no consensus as to the standard salvage therapy for these patients. In this study, we retrospectively evaluate safety and efficacy of a salvage regimen (CAGLP) consisting of G-CSF, low-dose cytarabine, aclarubicin, l-asparaginase and prednisone. Thirty-six patients were included with primary refractory (n=13) or relapse (n=23). The overall response rate (ORR) and CR rate were 86.1% and 63.9%, respectively. With a median follow-up of 34 months, the probability of overall survival (OS) at 2 years was 30%±10% and the disease-free survival (DFS) rate was 15%±8%. Treatment-related mortality was 5.6%. Our preliminary results indicated that CAGLP was feasible, safe and effective as a salvage reinduction chemotherapy for primary refractory and relapsed ALL patients.