Potential breakthroughs with investigational drugs for hairy cell leukemia

Clinical analysis of hairy cell leukemia: the rare indolent hematological malignancy

OBJECTIVE

To analyze the clinical features, diagnosis and treatment and prognosis of the rare hairy cell leukemia (HCL), in order to provide new references for the clinical and basic research of HCL.

METHODS

The clinical data of 17 patients with HCL admitted to Fujian Medical University Union Hospital, the Affiliated Hospital of Putian University and the First Affiliated Hospital of Gannan Medical University from January 1, 2016 to July 1, 2023 were collected and retrospectively studied, and the clinical features, diagnosis and treatment effects and prognosis of patients with HCL were analyzed. The Kaplan-Meier method was used for survival analysis. Meanwhile, the latest literature from PubMed was retrieved to systematically discuss the research progress in the diagnosis and treatment of HCL.

RESULTS

In this study, there were 11 males and 6 females, the median age at diagnosis was 59.5 (30-81) years old, and the median time from the onset of clinical symptoms or signs to diagnosis was 4.5 (0.5-28.5) months. There were 9 cases (52.94%) with lymphoma B symptoms (fever, night sweating, and weight loss), 15 cases (88.24%) were accompanied by splenomegaly (3 cases of mild splenomegaly, 4 cases of moderate splenomegaly, and 8 cases of megasplenomegaly), the positive rate of BRAFV600E mutation is 76.47% (13/17). All patients in this study were treated, of which 11 were treated with Cladribine, 3 with Interferon, 2 with FC regimen, and 1 with R-CVP regimen + Cladribine. The median follow-up time was 39 (range, 2-83) months, 3 patients died, all due to failure of chemotherapy due to disease progression. The prognosis of HCL-v patients was significantly worse than that of cHCL patients (P=0.01), and there was no significant difference in the impact of different treatment regiments on the OS of HCL patients (P=0.328).

CONCLUSION

HCL is a rare clinically indolent hematological tumor, which is sensitive to Cladribine, with the emergence of precision treatments such as the novel molecular-targeted drugs and immunotherapy also plays an indispensable role in clinical practice of HCL.

Targeting Protein Degradation Pathways in Tumors: Focusing on their Role in Hematological Malignancies

Cells must maintain their proteome homeostasis by balancing protein synthesis and degradation. This is facilitated by evolutionarily-conserved processes, including the unfolded protein response and the proteasome-based system of protein clearance, autophagy, and chaperone-mediated autophagy. In some hematological malignancies, including acute myeloid leukemia, misfolding or aggregation of the wild-type p53 tumor-suppressor renders cells unable to undergo apoptosis, even with an intact p53 DNA sequence. Moreover, blocking the proteasome pathway triggers lymphoma cell apoptosis. Extensive studies have led to the development of proteasome inhibitors, which have advanced into drugs (such as bortezomib) used in the treatment of certain hematological tumors, including multiple myeloma. New therapeutic options have been studied making use of the so-called proteolysis-targeting chimeras (PROTACs), that bind desired proteins with a linker that connects them to an E3 ubiquitin ligase, resulting in proteasomal-targeted degradation. This review examines the mechanisms of protein degradation in the cells of the hematopoietic system, explains the role of dysfunctional protein degradation in the pathogenesis of hematological malignancies, and discusses the current and future advances of therapies targeting these pathways, based on an extensive search of the articles and conference proceedings from 2005 to April 2022.

Skin changes in hairy cell leukemia

Skin lesions have been reported in about 10–12% of hairy cell leukemia (HCL) patients. Most are etiologically related to autoimmune or infectious processes, although secondary cutaneous neoplasms and drug-induced lesions are also reported. However, leukemia cutis with the direct infiltration of the skin by leukemic cells is extremely rare in HCL patients. This paper reviews the epidemiology, pathogenesis, clinical symptoms, diagnosis, and approach to treating skin lesions in HCL. A literature review of the MEDLINE database for articles in English concerning hairy cell leukemia, skin lesions, leukemia cutis, adverse events, infectious, cutaneous, drug reactions, neutrophilic dermatoses, secondary neoplasms, and vasculitis was conducted via PubMed. Publications from January 1980 to September 2020 were scrutinized. Additional relevant publications were obtained by reviewing the references from the chosen articles.

Bone lesions in hairy cell leukemia: Diagnosis and treatment

Skeletal involvement is a rare complication of hairy cell leukemia (HCL) with an incidence of approximately 3%. Bone lesions are commonly lytic, and the most common sites of involvement are the femoral head and neck. Skeletal involvement is typically associated with high tumor burden and bone marrow infiltration. However, isolated cases of skeletal disease without splenomegaly or bone marrow involvement are occasionally reported. This review focuses on skeletal lesions in HCL, particularly the pathogenesis, clinical symptoms, diagnostic methods, and treatment approach. A literature review of the MEDLINE database for articles in English concerning hairy cell leukemia, skeletal symptoms, bone involvement was conducted via PubMed. Publications from January 1970 to May 2020 were scrutinized. Additional relevant publications were obtained by reviewing the references from the chosen articles.

Classic hairy cell leukemia complicated by pancytopenia and severe infection: a report of 3 cases treated with vemurafenib

Infections are a major cause of morbidity and mortality in HCL patients, and myelosuppressive therapies increase the risk of poor outcomes. Vemurafenib achieves rapid hematologic improvement in HCL and may facilitate management during life-threatening infection.

Moxetumomab pasudotox for the treatment of hairy cell leukemia

Introduction: Cladribine and pentostatin are the drugs of choice in the treatment of hairy cell leukemia (HCL). Recently, immunotoxin moxetumomab pasudotox has been introduced to improve the prognosis in relapsed and refractory HCL. Areas covered: This review discusses the mechanism of action, safety, and efficacy of moxetumomab pasudotox in HCL patients. A literature review of the MEDLINE database for articles in English concerning immunotoxins, moxetumomab pasudotox, and hairy cell leukemia was conducted via PubMed. Publications from 2000 through December 2018 were scrutinized. The search terms used were immunotoxins and moxetumomab pasudotox in conjunction with hairy cell leukemia. Conference proceedings from the previous five years of the American Society of Hematology, European Hematology Association and American Society of Clinical Oncology were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles. Results/conclusion: Moxetumomab pasudotox, a novel recombinant anti-CD22 immunotoxin, was well tolerated and active in the previous phase 1 and 3 studies in patients with HCL. The drug has been approved in 2018 by the FDA for the treatment of patients with relapsed/refractory HCL who had at least two prior systemic therapies including at least one purine nucleoside analog. Expert opinion: The use of moxetumomab pasudotox is a promising new strategy for the treatment of HCL.

Moxetumomab pasudotox: A first-in-class treatment for hairy cell leukemia

Hairy cell leukemia is a rare indolent B-cell lymphoid malignancy. Durable remission can be obtained with purine analogues, but relapse is inevitable, and effective treatment options may be limited. Moxetumomab pasudotox is a recombinant CD22-targeting immunotoxin that has recently been approved by the United States Food and Drug Administration for the treatment of relapsed or refractory hairy cell leukemia. Approval was based on a pivotal phase III study in this unique patient population. Rationale for use, clinical trial data, and current treatment recommendations are detailed. Common adverse effects are reviewed, and management strategies for select adverse effects are suggested. Implications for contemporary practitioners are also provided, as use of this novel agent is likely to increase as follow-up studies are reported.

Emerging antibody-drug conjugates for treating lymphoid malignancies

INTRODUCTION

Antibody-drug conjugates (ADC) are monoclonal antibodies (Mabs) attached to biologically active drugs through specialized chemical linkers. They deliver and release cytotoxic agents at the tumor site, reducing the likelihood of systemic exposure and therefore toxicity. These agents should improve the potency of chemotherapy by increasing the accumulation of cytotoxic the drug within or near the neoplastic cells with reduced systemic effects. Areas covered: A literature review was conducted of the MEDLINE database PubMed for articles in English examining Mabs, B-cell receptor pathway inhibitors and immunomodulating drugs. Publications from 2000 through April 2017 were scrutinized. Conference proceedings from the previous five years of the American Society of Hematology, European Hematology Association, American Society of Clinical Oncology, and ACR/ARHP Annual Scientific Meetings were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles. Expert opinion: Newer ADCs show promise as treatment for several hematologic malignancies, especially lymphoma, multiple myeloma, and leukemia. However, definitive data from ongoing and future clinical trials will aid in better defining the status of these agents in the treatment of these diseases.