Venetoclax treatment of patients with relapsed T-cell prolymphocytic leukemia

Partial response to venetoclax and ruxolitinib combination in a case of refractory T-prolymphocytic leukemia

Background: T-prolymphocytic leukemia (T-PLL) is an aggressive hematologic malignancy. A portion of patients can be cured with alemtuzumab induction followed by allogeneic hematopoietic stem cell transplant, but patients who relapse after transplant have a poor prognosis, and there is no standard of care.Methods: We report a case of a 64-year-old man with relapsed JAK3-mutant T-PLL following allogeneic transplant who was treated with ruxolitinib and venetoclax.Results: Treatment with ruxolitinib and venetoclax resulted in a partial response including stabilization of the peripheral lymphocyte count, improvement in thrombocytopenia, decrease in splenomegaly, and a numerical reduction in the percentage of bone marrow involved by T-PLL. The combination was well tolerated with the exception of neutropenic infections.Conclusion: This case adds to the growing body of literature supporting venetoclax and rituximab as a viable treatment option for relapsed/refractory T-PLL with JAK-STAT alterations.

Clinical analysis of prolymphoblastic leukemia: the rare hematological malignancy in the elderly

OBJECTIVE

To discuss and analyze the clinical and prognostic characteristics of rare prolymphocytic leukemia (PLL), in order to provide new references for the clinical diagnosis and treatment and basic research of PLL.

METHODS

The clinical data of 8 patients with PLL admitted to the Department of Hematology in Fujian Medical University Union Hospital from January 1, 2011 to May 31, 2023 were collected and retrospectively studied, and the clinical treatment and prognosis were analyzed. Meanwhile, the latest literature from PubMed was retrieved to systematically discuss the research progress in the diagnosis and treatment of PLL.

RESULTS

In this study, of the 8 patients with PLL, 6 were males and 2 were females; the ages ranged from 52 to 80 years, with a median age of 70.5 years. The immunophenotypes were divided into B-PLL (7 cases) and T-PLL (1 case). Morphological, flow cytometric, cytogenetic and molecular biological tests of bone marrow cells were performed in all patients. Among them, 1 case refused chemotherapy after diagnosis and died in a short time, the other 7 cases received standard chemotherapy. Among the 7 patients, one patient died of severe infection caused by myelosuppression after chemotherapy, one patient died within 3 months after chemotherapy; two patients died of progression at 4 and 7 months after chemotherapy. A total of 3 patients achieved complete remission (CR) after chemotherapy, and 1 patient underwent allogeneic hematopoietic stem cell transplantation without disease progression or recurrence.

CONCLUSION

PLL is a rare lymphoid malignancy with an extremely poor prognosis, which tends to occur in the elderly, and the clinical manifestations of PLL lack specificity. Chemotherapy combined with targeted drugs or epigenetic drugs may benefit PLL patients. Hematopoietic stem cell transplantation should be performed after CR is obtained to improve the prognosis to the greatest extent.

T-Cell Prolymphocytic Leukemia: Diagnosis, Pathogenesis, and Treatment

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive neoplasm of mature T-cells. Most patients with T-PLL present with lymphocytosis, anemia, thrombocytopenia, and hepatosplenomegaly. Correct identification of T-PLL is essential because treatment for this disease is distinct from that of other T-cell neoplasms. In 2019, the T-PLL International Study Group (TPLL-ISG) established criteria for the diagnosis, staging, and assessment of response to treatment of T-PLL with the goal of harmonizing research efforts and supporting clinical decision-making. T-PLL pathogenesis is commonly driven by T-cell leukemia 1 (TCL1) overexpression and ATM loss, genetic alterations that are incorporated into the TPLL-ISG diagnostic criteria. The cooperativity between TCL1 family members and ATM is seemingly unique to T-PLL across the spectrum of T-cell neoplasms. The role of the T-cell receptor, its downstream kinases, and JAK/STAT signaling are also emerging themes in disease pathogenesis and have obvious therapeutic implications. Despite improved understanding of disease pathogenesis, alemtuzumab remains the frontline therapy in the treatment of naïve patients with indications for treatment given its high response rate. Unfortunately, the responses achieved are rarely durable, and the majority of patients are not candidates for consolidation with hematopoietic stem cell transplantation. Improved understanding of T-PLL pathogenesis has unveiled novel therapeutic vulnerabilities that may change the natural history of this lymphoproliferative neoplasm and will be the focus of this concise review.

Advanced Pathogenetic Concepts in T-Cell Prolymphocytic Leukemia and Their Translational Impact

T-cell prolymphocytic leukemia (T-PLL) is the most common mature T-cell leukemia. It is a typically aggressively growing and chemotherapy-resistant malignancy with a poor prognosis. T-PLL cells resemble activated, post-thymic T-lymphocytes with memory-type effector functions. Constitutive transcriptional activation of genes of the T-cell leukemia 1 (TCL1) family based on genomic inversions/translocations is recognized as a key event in T-PLL's pathogenesis. TCL1's multiple effector pathways include the enhancement of T-cell receptor (TCR) signals. New molecular dependencies around responses to DNA damage, including repair and apoptosis regulation, as well as alterations of cytokine and non-TCR activation signaling were identified as perturbed hallmark pathways within the past years. We currently witness these vulnerabilities to be interrogated in first pre-clinical concepts and initial clinical testing in relapsed/refractory T-PLL patients. We summarize here the current knowledge on the molecular understanding of T-PLL's pathobiology and critically assess the true translational progress around this to help appraisal by caregivers and patients. Overall, the contemporary concepts on T-PLL's pathobiology are condensed in a comprehensive mechanistic disease model and promising interventional strategies derived from it are highlighted.

Keeping up with venetoclax for leukemic malignancies: key findings, optimal regimens and clinical considerations

INTRODUCTION

Venetoclax has transformed the treatment landscape in hematologic malignancies, especially in elderly population. With high rates of remission, deep and durable responses, and safe toxicity profile, venetoclax in combination therapy has been extremely effective, garnering accelerated approval and becoming standard of care in lymphoid and myeloid malignancies.

AREAS COVERED

The role of venetoclax in the intrinsic apoptotic pathway is covered. This includes preclinical and clinical experience of venetoclax monotherapy and combination therapy in relapsed/refractory and frontline CLL, AML, ALL and high-risk MDS, with an emphasis on key clinical trials and efficacy of combination regimens in distinct mutational landscapes. Strategies to mitigate myelosuppression, manage dose adjustments and infectious complications are addressed.

EXPERT OPINION

Targeting BCL-2 offers a safe and highly effective adjunct to available therapies in hematologic malignancies. Despite success and frequent utilization of venetoclax, several resistance mechanisms have been elucidated, prompting development of novel combinatorial strategies. Further, on-target myelosuppression of venetoclax is a key obstacle in clinical practice, requiring diligent monitoring and practice-based knowledge of dose modifications. Despite these limitations, venetoclax has gained tremendous popularity in hematologic-oncology, becoming an integral component of numerous combination regimes, with ongoing plethora of clinical trials encompassing standard chemotherapy, targeted agents and immune-based approaches.