Venetoclax and Decitabine in Pediatric Refractory T-cell Lymphoblastic Lymphoma

Developing Targeted Therapies for T Cell Acute Lymphoblastic Leukemia/Lymphoma

PURPOSE OF REVIEW

Largely, treatment advances in relapsed and/or refractory acute lymphoblastic leukemia (ALL) have been made in B cell disease leaving T cell ALL reliant upon high-intensity chemotherapy. Recent advances in the understanding of the biology of T-ALL and the improvement in immunotherapies have led to new therapeutic pathways to target and exploit. Here, we review the more promising pathways that are able to be targeted and other therapeutic possibilities for T-ALL.

RECENT FINDINGS

Preclinical models and early-phase clinical trials have shown promising results in some case in the treatment of T-ALL. Targeting many different pathways could lead to the next advancement in the treatment of relapsed and/or refractory disease. Recent advances in cellular therapies have also shown promise in this space. When reviewing the literature as a whole, targeting important pathways and antigens likely will lead to the next advancement in T-ALL survival since intensifying chemotherapy.

Effects of post-transplant maintenance therapy with decitabine prophylaxis on the relapse for acute lymphoblastic leukemia

In adults with acute lymphoblastic leukemia (ALL), post-transplant relapse is a major risk factor for mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Our study investigated the efficacy and safety of decitabine (dec) with ALL patients post-transplantation. We performed a retrospective cohort study to assess the efficacy of decitabine (dec) with post-transplant ALL at the First Affiliated Hospital of Zhengzhou University from February 2016 to September 2021. A total of 141 consecutive ALL patients were analyzed and divided into decitabine (dec, n = 65) and control (ctrl, n = 76) groups based on whether they were treated with decitabine after allo-HSCT. The 3-year cumulative incidence of relapse (CIR) rate in the dec group was lower than that in the ctrl group (19.6 vs. 36.1%, p = 0.031), with a hazard ratio of 0.491 (95% confidence interval [CI], 0.257-0.936). Additionally, subgroup analyses revealed that the 3-year CIR rate of T-ALL and Ph-negative B-ALL patients in the dec and ctrl groups was 11.7 vs. 35.9% and 19.5 vs. 42.2% (p = 0.035, p = 0.068) respectively. In summary, ALL patients, especially those with T-ALL and Ph-negative B-ALL, may benefit from decitabine as maintenance therapy following allo-HSCT.

T-cell acute lymphoblastic leukemia: promising experimental drugs in clinical development

INTRODUCTION

Despite advances in treatment approaches in acute lymphoblastic leukemia (ALL), the prognosis of adults with newly diagnosed T-ALL remains poor, as well as that of adults and children with relapsed disease. Novel targeted therapies are therefore needed.

AREAS COVERED

This review summarizes promising emerging strategies for the treatment of T-ALL.

EXPERT OPINION

The recent molecular characterization of T-ALL has led to the identification of new therapeutic targets. Small-molecules inhibitors and other targeted therapies have therefore been recently developed and are currently under clinical investigations. Similarly, first studies involving monoclonal antibodies and chimeric antigen receptor (CAR) T cells have shown encouraging results. Improvement of outcome with these novel approaches, eventually combined with current standard chemotherapy, is therefore expected in a near future in T-ALL.

Venetoclax for Children and Adolescents with Acute Lymphoblastic Leukemia and Lymphoblastic Lymphoma

Simple Summary

Pediatric patients with relapsed or refractory acute lymphoblastic leukemia (ALL) or lymphoma (LBL) currently have unsatisfactory outcomes, and novel treatment options are needed. Venetoclax is approved for adult patients with several types of leukemia and is being investigated in the pediatric population. Here, we retrospectively reviewed the safety and efficacy of venetoclax for the treatment of ALL/LBL in the pediatric and young adult populations. The purpose of this study is to provide evidence that venetoclax is safe and effective to use in pediatric patients with ALL/LBL and should be considered in both the relapsed and upfront settings.

Abstract

Venetoclax is approved for adult patients with chronic lymphocytic leukemia and acute myeloid leukemia. Expanding its use to the pediatric population is currently under investigation, but more robust data are needed. We retrospectively analyzed the safety and efficacy of venetoclax in children/AYA with ALL/LBL. We identified 18 patients (T-cell ALL, n = 7; T-cell LBL, n = 6; B-cell ALL, n = 5) aged 6–22 years. No new venetoclax safety signals were identified; the most common toxicity was myelosuppression. No deaths occurred within 30 days from the start of the therapy. A mean of 2.6 (range 0–8) prior lines of therapy were given. The mean duration of venetoclax was 4.06 months (range 0.2–24.67 months). Complete remission was achieved in 11 (61%) patients. Of the eight patients who remain alive, four are continuing on venetoclax combination therapy, and four proceeded to hematopoietic stem cell transplantation. Three patients who initially achieved CR, later relapsed, and are deceased. Nine patients are deceased, and one patient was lost to follow-up. Overall survival is 9.14 months (range 1.1–33.1), and progression-free survival is 7.34 months (range 0.2–33.1). This is the largest cohort of pediatric/AYA patients who received venetoclax for ALL/LBL. Our data support the consideration of venetoclax-based regimens in pediatric patients with R/R ALL/LBL and its investigation as upfront therapy for T-cell ALL/LBL.