The superiority of allogeneic hematopoietic stem cell transplantation from unrelated donor over chemotherapy for adult patients with high-risk acute lymphoblastic leukemia in first remission

Maintenance Treatment With Low-Dose Decitabine After Allogeneic Hematopoietic Cell Transplantation in Patients With Adult Acute Lymphoblastic Leukemia

Background

Post-transplant relapse remains a principal leading cause of failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with adult acute lymphoblastic leukemia (ALL). The aim of this study was to investigate the efficacy and safety of low-dose decitabine on the prevention of adult ALL relapse after allo-HSCT.

Methods

In this prospective study, we enrolled 34 patients with ALL who underwent allo-HSCT from August 2016 to April 2020 and received low-dose decitabine maintenance treatment after transplantation. The primary objectives were cumulative incidence of relapse rate (CIR), overall survival (OS), and disease-free survival (DFS). The secondary objectives were graft-versus-host disease (GVHD) and safety.

Results

Among the enrolled 34 patients, 6 patients relapsed and 6 patients died. The 2-year CIR, OS, and DFS were 20.2, 77.5, and 73.6%, respectively. Subgroup analysis revealed the 2-year CIR, OS, and DFS rates of 12 patients with T-ALL/lymphoblastic lymphoma (LBL) were 8.3, 90, and 81.5%, respectively. None of the seven patients with T-ALL relapsed. During maintenance treatment, only one patient (2.9%) developed grade IV acute GVHD and four (11.8%) patients had severe chronic GVHD. Thirty-two patients (94.1%) developed only grade I to II myelosuppression, and two patients (5.8%) developed grade III to IV granulocytopenia.

Conclusions

Maintenance treatment with low-dose decitabine after allo-HSCT may be used as a therapeutic option to reduce relapse in patients with adult ALL, especially in patients with T-ALL. Our findings require confirmation in larger-scale controlled trials.

Clinical Trial Registration

Chinese Clinical Trials Registry, identifier ChiCTR1800014888.

Outcomes of Adolescent Patients with Acute Lymphoblastic Leukemia: Long-term Follow-up of 335 Patients

BACKGROUND

Adolescents (aged 10-17 years) with acute lymphoblastic leukemia (ALL) represent a unique patient population, with a disproportionate survival disadvantage compared with younger patients. We aimed to determine the outcomes and prognostic factors of adolescent patients treated at our institution.

PATIENTS AND METHODS

Between 2005 and 2017, 335 adolescents with ALL were enrolled; clinical characteristics and treatment outcomes were analyzed and compared between adolescents and younger children (1-9 years old, n = 704).

RESULTS

Adolescents were more likely to have high-risk factors such as hyperleukocytosis, a T-cell immunophenotype, BCR-ABL1, and/or poor early treatment responses. Compared with younger children, adolescents had significantly worse 5-year event-free survival (EFS) (73.0% ± 2.5% vs. 82.6% ± 1.5%; P < .001) and overall survival (OS) (77.1% ± 2.3% vs. 87.7% ± 1.3%; P < .001). Furthermore, younger adolescents (10-14 years) tended to have better outcomes compared with those older than 15 years (5-year OS: 79.3% ± 2.5% vs. 68.4% ± 5.7%; P = .042), mainly because of the lower frequencies of toxicities. On multivariate analysis, white blood count ≥ 50 × 10⁹/L and extramedullary involvement at diagnosis were the most powerful prognostic factors for both OS and EFS.

CONCLUSION

The outcomes among adolescent patients were not as good as that of younger children. Further studies are required to define optimal treatment strategies for adolescents, particularly those aged 15 to 17 years.

Measurable Residual Disease Assessment and Allogeneic Transplantation as Consolidation Therapy in Adult Acute Lymphoblastic Leukemia in Colombia

INTRODUCTION

Detectable minimal residual disease (MRD) after therapy for acute lymphoblastic leukemia (ALL) is the strongest predictor of hematologic relapse. The objective of the study was to assess disease-free survival (DFS) and overall survival (OS) of patients with ALL according with MRD status at the end of induction therapy in a Colombian population.

PATIENTS AND METHODS

We assessed a retrospective cohort to compare DFS and OS in adults with de novo ALL according to MRD status at the end of induction chemotherapy, and the type of postinduction consolidation strategy used.

RESULTS

A total of 165 adults with ALL were included in the MRD part of the study, 73 patients in the MRD-negative group and 92 in the MRD-positive group. Median DFS for the MRD-positive group was 11 months (95% confidence interval, 11.7-22.2) and was not reached for the MRD-negative group (P < .001). At 3 years, DFS was 18% and 55%, respectively (P < .001). The median OS for MRD-positive patients was 16 months (95% confidence interval, 8.8-23.15) and was not reached in the MRD-negative group. At 3 years, OS was 26% and 51% for the former and latter group, respectively. Among subjects who did not receive a transplant, median DFS was 21 months for MRD-negative patients and 9 months for MRD-positive patients (P < .001). The median DFS was not reached in either group, whereas 3-year DFS was 64% for MRD-negative and 70% for MRD-positive patients who underwent transplantation in first remission (P = .861).

CONCLUSION

MRD status at the end of induction is an independent prognostic factor for DFS and OS in adult ALL. Allogeneic transplantation in first remission could overcome the adverse prognostic impact of MRD.

The photosensitizer verteporfin has light-independent anti-leukemic activity for Ph-positive acute lymphoblastic leukemia and synergistically works with dasatinib

Cell lines have been used for drug discovery as useful models of cancers; however, they do not recapitulate cancers faithfully, particularly from the viewpoints of microenvironmental independence. Patient-derived xenografts (PDX) are established by the transfer of primary tumor cells directly from patients into immunodeficient mice and can provide primary-like tumor cells of the amount needed at the desired time. We developed a high-throughput drug screening system using PDX cells and performed drug screening using the PDX cells of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL). We established four Ph⁺ ALL PDX mice and performed high-throughput screening of 3440 compounds using leukemia cells from the PDX mice (PDX-cell screening). The profiles of drugs selected by PDX-cell screening were markedly different from those by screening using the Ph⁺ ALL cell line. We found that verteporfin, an FDA-approved drug, exhibited strong PDX cell-specific cytotoxicity. In the validation assay, its GI₅₀ was 228 nM, 395 nM, and 538 nM in three PDX cells and 3.93 μM, 2.11 μM, and 5.61 μM in three cell lines. Although verteporfin is a photosensitizer activated by photoirradiation, its cytotoxic effects were mediated by the light-independent production of reactive oxygen species; therefore, its anti-leukemic effects were also exerted in vivo without photoirradiation. Furthermore, it exhibited synergistic effects with dasatinib, an ABL kinase inhibitor. These results indicated the potential of verteporfin as a new anti-leukemic reagent.