Response to the Therapy in Hairy Cell Leukemia: Systematic Review and Meta-Analysis

Challenges in the Management of a Difficult-to-Treat Patient With Hairy Cell Leukemia: A Case Report

Hairy cell leukemia (HCL) is a rare, chronic B-cell malignancy with an indolent course that typically responds well to purine nucleoside analogs, such as cladribine. We present the case of a 74-year-old woman with nearly three decades of recurrent HCL, marked by multiple relapses and significant toxicities to various treatments, including purine analogs, BRAF inhibitors, BTK inhibitors, a cytoreductive agent, and the monoclonal antibody rituximab. Despite severe allergic reactions and intolerances to standard therapies, the patient achieved multiple remissions. This case underscores the challenges in managing treatment-resistant HCL and highlights the need for personalized treatment strategies in patients with relapsed disease and drug toxicities.

Hairy cell leukemia 2024: Update on diagnosis, risk-stratification, and treatment-Annual updates in hematological malignancies

DISEASE OVERVIEW

Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogenous group of mature lymphoid B-cell disorders characterized by the identification of hairy cells, a specific genetic profile, a different clinical course and the need for appropriate treatment.

DIAGNOSIS

Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of 3 or 4 based on the CD11c, CD103, CD123, and CD25 expression, the trephine biopsy which makes it possible to specify the degree of tumoral bone marrow infiltration and the presence of BRAFV600E somatic mutation.

RISK STRATIFICATION

Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood, and the immunoglobulin heavy chain variable region gene mutational status. VH4-34 positive HCL cases are associated with a poor prognosis, as well as HCL with TP53 mutations and HCL-V.

TREATMENT

Patients should be treated only if HCL is symptomatic. Chemotherapy with risk-adapted therapy purine analogs (PNAs) are indicated in first-line HCL patients. The use of chemo-immunotherapy combining cladribine (CDA) and rituximab (R) represents an increasingly used therapeutic approach. Management of relapsed/refractory disease is based on the use of BRAF inhibitors (BRAFi) plus R, MEK inhibitors (MEKi), recombinant immunoconjugates targeting CD22, Bruton tyrosine kinase inhibitors (BTKi), and Bcl-2 inhibitors (Bcl-2i). However, the optimal sequence of the different treatments remains to be determined.

Primary splenic T-cell/histiocyte-rich B-cell lymphoma in a patient with recurrent hairy cell leukemia: a case report

T-cell/histiocyte-rich B-cell lymphoma is a high-grade, morphologic variant of diffuse large B-cell lymphoma. T-cell/histiocyte-rich B-cell lymphoma. It is rare as a primary splenic involvement and is usually reported as a second malignancy after hairy cell leukemia. Here, we report the first case that describes the occurrence of primary splenic T-cell/histiocyte-rich B-cell lymphoma in a patient with a previous diagnosis of recurrent hairy cell leukemia. A 53-year-old male patient was diagnosed with hairy cell leukemia in 1996 and achieved complete remission with Pentostatin. Then, recurrence of hairy cell leukemia was diagnosed in 2015 and treated with Cladribine. In 2016, he presented with B symptoms and hypersplenism. Therapeutic and diagnostic splenectomy was performed. Histopathological study with immunohistochemistry evaluation revealed the presence of T-cell/histiocyte-rich B-cell lymphoma. Therefore, second malignancies should be considered in patients with a previous neoplasm when symptoms recur or develop.

A 3-decade multicenter European experience with cladribine as upfront treatment in 384 hairy cell leukemia patients

Cladribine is regarded as the first treatment of choice for symptomatic hairy cell leukemia.

This large international study reports a complete response in 72% of cases and a continuous complete response in 20% of patients.

Hairy cell leukemia 2022: Update on diagnosis, risk-stratification, and treatment

DISEASE OVERVIEW

Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogeneous group of mature lymphoid B-cell disorders characterized by the identification of hairy cells, a specific genetic profile, a different clinical course, and the need for appropriate treatment.

DIAGNOSIS

Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of 3 or 4 based on the CD11C, CD103, CD123, and CD25 expression, the trephine biopsy which makes it possible to specify the degree of tumoral medullary infiltration and the presence of BRAF^V600E somatic mutation.

RISK STRATIFICATION

Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood, and the immunoglobulin heavy chain variable region gene mutational status. VH4-34-positive HCL cases are associated with a poor prognosis.

TREATMENT

Patients should be treated only if HCL is symptomatic. Chemotherapy with risk adapted therapy purine analogs (PNAs) are indicated in first-line HCL patients. The use of chemo-immunotherapy combining PNAs and rituximab (R) represents an increasingly used therapeutic approach. Management of relapsed/refractory disease is based on the use of BRAF inhibitors (BRAFi) plus rituximab or MEK inhibitors (MEKi), recombinant immunoconjugates targeting CD22 or Bruton Tyrosine Kinase inhibitors (BTKi). However, the optimal sequence of the different treatments remains to be determined. The Bcl2-inhibitors (Bcl-2i) can play a major role in the future.

MAP-Kinase-Driven Hematopoietic Neoplasms: A Decade of Progress in the Molecular Age

Mutations in members of the mitogen-activated protein kinase (MAPK) pathway are extensively studied in epithelial malignancies, with BRAF mutations being one of the most common alterations activating this pathway. However, BRAF mutations are overall quite rare in hematological malignancies. Studies over the past decade have identified high-frequency BRAF V600E, MAP2K1, and other kinase alterations in two groups of MAPK-driven hematopoietic neoplasms: hairy cell leukemia (HCL) and the systemic histiocytoses. Despite HCL and histiocytoses sharing common molecular alterations, these are phenotypically distinct malignancies that differ in respect to clinical presentation and suspected cell of origin. The purpose of this review is to highlight the molecular advancements over the last decade in the histiocytic neoplasms and HCL and discuss the impact these insights have had on our understanding of the molecular pathophysiology, cellular origins, and therapy of these enigmatic diseases as well as perspectives for future research directions.

Complete remission of aggressive T-cell LGL leukemia with pentostatin therapy: first case report

This is the first report of a complete remission in aggressive T-cell large granular lymphocytic (T-LGL) leukemia after treatment with pentostatin. The aggressive variant of the disease is rare, and traditional therapies include immunosuppressive agents, however, there is no standard consensus for treatment. Cytotoxic chemotherapy has led to remission in a few reported cases. We present this unique case as an alternative treatment for individuals refractory to chemotherapy. A 55-year-old African American male with hypertension, type II diabetes mellitus, hyperlipidemia, and gout presented with symptoms of multiple ecchymosis, fatigue, and weight loss. He was found to have splenomegaly (SM) and significant leukocytosis to 101 k/µL with 30% blasts on peripheral smear. Following bone marrow aspiration and biopsy with flow cytometry, he was diagnosed with aggressive T-LGL leukemia. The chemotherapy regimen hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone) was initially chosen based on his clinical presentation but was refractory to treatment. His therapy was changed to alemtuzumab; however, patient tolerated poorly and did not respond. Pentostatin was added to alemtuzumab with improvement in clinical symptoms and laboratory parameters. The patient was transitioned to pentostatin monotherapy and achieved complete remission after 1 month. This report provides support for pentostatin as an effective treatment for patients with aggressive T-cell malignancies refractory to cytotoxic chemotherapy. Pentostatin has previously been studied to treat T-cell prolymphocytic leukemia (T-PLL), hairy cell leukemia, and marginal zone lymphoma. This case suggests an alternative, well-tolerated option that could be considered for initial therapy of aggressive T-LGL leukemia.

"Hairy Cell Leukemia (HCL): 'Real World' Outcome"

HCL is an uncommon B cell lympho-proliferative disorder with high remission rates. There is paucity of data on the long-term outcome of HCL from India. We retrospectively collected data from individual case records of patients with HCL who were treated in Cancer Institute, Chennai from January 2001 until January 2018. Sixteen patients were diagnosed with HCL and were treated with cladribine (81%), interferon (13%) and one patient received only best supportive care (6%). All the treated patients achieved complete response. More than half of the patients developed febrile neutropenia but there were no treatment related mortality. The 5-year DFS was 77% and 5-year OS was 80%. Relapse of disease was seen in 27%. HCL is a curable malignancy with high remission rates and survival comparable to patient treated in west.

Hairy cell leukemia: present and future directions

Hairy cell leukemia (HCL) is an indolent B-cell malignancy, with long-term responses to purine analogs, but with decreasing efficacy and increasing toxicity with repeated courses. Leukemic cells express CD22, CD20, CD25, tartrate-resistant acid phosphatase (TRAP), annexin 1A (Anxa1), and BRAF V600E mutation. HCLv, lacking CD25, Anxa1, TRAP, and BRAF V600E, is more aggressive and less purine analog-sensitive. A molecularly defined IGHV4-34+ variant is also resistant whether HCL or HCLv immunophenotypically. Traces of HCL cells, termed minimal residual disease (MRD), accompany most with complete remission (CR) and may cause relapse. Rituximab has limited single-agent activity, but frequent CR without MRD when combined with purine analog, albeit with chemotherapy toxicities. The anti-CD22 recombinant immunotoxin Moxetumomab Pasudotox can achieve MRD-negative CR in multiply relapsed HCL without chemotherapy toxicities and was FDA approved in 2018 as Lumoxiti. Investigational oral non-chemotherapy options also include Vemurafenib or Dabrafenib/Trametinib targeting BRAF V600E ± MEK, and Ibrutinib targeting Bruton's tyrosine kinase.

Hairy cell leukemia: 2020 update on diagnosis, risk stratification, and treatment

DISEASE OVERVIEW

Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogeneous group of mature lymphoid B-cell disorders. They are characterized by the identification of hairy cells, a specific genetic profile, a different clinical course and the need for appropriate treatment.

DIAGNOSIS

Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of three or four based on the CD11C, CD103, CD123, and CD25 expression. Also, the trephine biopsy which makes it possible to specify the degree of tumoral medullary infiltration and the presence of BRAF V600E somatic mutation.

RISK STRATIFICATION

Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood and the immunoglobulin heavy chain variable region gene mutational status. The VH4-34 positive HCL cases are associated with poor prognosis.

TREATMENT

Risk adapted therapy with purine nucleoside analogs (PNA) are indicated in symptomatic first line HCL patients. The use of PNA followed by rituximab represents an alternative option. Management of progressive or refractory disease is based on the use of BRAF inhibitors associated or not with MEK inhibitors, recombinant immunoconjugates targeting CD22 or BCR inhibitors.

Retrospective Analysis of Hairy Cell Leukemia Patients Treated with Different Modalities as First Line: Real-Life Experience Over 20 years

We aimed to analyze the characteristics and response rates of different treatment modalities in hairy cell leukemia patients over 20 diagnosed as hairy cell leukemia (HCL). Clinical data, response rates and survival outcome of the patients who were diagnosed with HCL were retrospectively analyzed. Fifty-two patients with a median age of 50 (28-87) years were enrolled in the study. 38 patients (73%) were male and male to female ratio was 2.7. First line therapy was cladrabine in 36 patients (69.2%). The overall response rate was 97%. CR and PR rates were 86.1% and 11.1%, respectively. Interferon was used in 10(19.2%) patients who were diagnosed before 2000s years. CR and PR rates were 70% and 30%, respectively. Although the CR rates were lower in IFN group, this difference could not be reached statistically significance (p = 0.24). The median follow up was 48 months (12-252). The median OS was not reached and median PFS was 150 months (95% CI, 116-214). The OS at 36 and 48 months were 95.9% and 92.3%, respectively and the PFS at 36 and 48 months were 90.2% and 83.4%, respectively. After the introduction of purine analogues, the fate of the HCL patients have been changed. Cladrabin achieved very high response rates in both young and older patients, in our study. Although relapse still constitutes a problem, another single dose of cladrabine results in good response rates.