How I treat refractory/relapsed hairy cell leukemia with BRAF inhibitors

Single agent vemurafenib or rituximab-vemurafenib combination for the treatment of relapsed/refractory hairy cell leukemia, a multicenter experience

BACKGROUND

Hairy cell leukemia (HCL) is a rare mature B-cell malignancy that is primarily treated with purine analogues. However, relapse remains a significant challenge, prompting the search for alternative therapies. The BRAF V600E mutation prevalent in HCL patients provides a target for treatment with vemurafenib.

PATIENTS AND METHODS

This multicenter retrospective study included nine patients with relapsed/refractory (R/R) HCL from six different centers. Patient data included demographics, prior treatments, clinical outcomes, and adverse events.

RESULTS

Patients received different treatment regimens between centers, including vemurafenib alone or in combination with rituximab. Despite the differences in protocols, all patients achieved at least a partial response, with seven patients achieving a complete response. Adverse events were generally mild with manageable side effects. The absence of myelotoxic effects and manageable side effects make BRAF inhibitors attractive, especially for patients ineligible for purine analogues or those with severe neutropenia.

CONCLUSION

Single agent vemurafenib or in combination with rituximab appears to be a promising therapeutic option for R/R HCL. Further research is needed to establish standardized treatment protocols and to investigate long-term outcomes.

An unusual form of BRAF-V600E mutated hairy cell neoplasm with clinical resistance to BRAF inhibition: Challenging precision medicine

Distinct outcomes of BRAF inhibition in BRAF-mutated hairy cell neoplasms with wild-type or mutant TP53, and alternative strategies to overcome mutant TP53.

Hairy Cell Leukemia: Where Are We in 2023?

PURPOSE OF REVIEW

This article summarizes the current state of knowledge of hairy cell leukemia (HCL) regarding presentation, diagnosis, therapy, and monitoring, including perspectives on emergent therapies.

RECENT FINDINGS

Over the past decade, there has been enormous progress in the understanding of the biology of HCL which has led to the development of novel therapeutic strategies. The maturation of data regarding existing management strategies has also lent considerable insight into therapeutic outcomes and prognosis of patients treated with chemo- or chemoimmunotherapy. Purine nucleoside analogs remain the cornerstone of treatment, and the addition of rituximab has deepened and prolonged responses in the upfront and relapsed setting. Targeted therapies now have a more defined role in the management of HCL, with BRAF inhibitors now having a potential in the first-line setting in selected cases as well as in relapse. Next-generation sequencing for the identification of targetable mutations, evaluation of measurable residual disease, and risk stratification continue to be areas of active investigation. Recent advances in HCL have led to more effective therapeutics in the upfront and relapsed setting. Future efforts will focus on identifying patients with high-risk disease who require intensified regimens. Multicenter collaborations are the key to improving overall survival and quality of life in this rare disease.

The protective role of the microenvironment in hairy cell leukemia treatment: Facts and perspectives

Hairy cell leukemia (HCL) is an incurable, rare lymphoproliferative hematological malignancy of mature B cAlthough first line therapy with purine analogues leads to positive results, almost half of HCL patients relapse after 5-10 years, and standard treatment may not be an option due to intolerance or refractoriness. Proliferation and survival of HCL cells is regulated by surrounding accessory cells and soluble signals present in the tumor microenvironment, which actively contributes to disease progression. In vitro studies show that different therapeutic approaches tested in HCL impact the tumor microenvironment, and that this milieu offers a protection affecting treatment efficacy. Herein we explore the effects of the tumor microenvironment to different approved and experimental therapeutic options for HCL. Dissecting the complex interactions between leukemia cells and their milieu will be essential to develop new targeted therapies for HCL patients.

Precision Medicine in Therapy of Non-solid Cancer

The development and approval of the tyrosine kinase inhibitor imatinib in 2001 has heralded the advance of directed therapy options. Today, an armamentarium of targeted therapeutics is available and enables the use of precision medicine in non-solid cancer. Precision medicine is guided by the detection of tumor-specific and targetable characteristics. These include pathogenic fusions and/or mutations, dependency on specific signaling pathways, and the expression of certain cell surface markers. Within the first part, we review approved targeted therapies for the compound classes of small molecule inhibitors, antibody-based therapies and cellular therapies. Particular consideration is given to the underlying pathobiology and the respective mechanism of action. The second part emphasizes on how biomarkers, whether they are of diagnostic, prognostic, or predictive relevance, are indispensable tools to guide therapy choice and management in precision medicine. Finally, the examples of acute myeloid leukemia, chronic lymphocytic leukemia, and chronic myeloid leukemia illustrate how integration of these biomarkers helps to tailor therapy.

A comparison of the International Consensus and 5th World Health Organization classifications of mature B-cell lymphomas

Several editions of the World Health Organization (WHO) classifications of lympho-hemopoietic neoplasms in 2001, 2008 and 2017 served as the international standard for diagnosis. Since the 4th WHO edition, here referred as WHO-HAEM4, significant clinico-pathological, immunophenotypic and molecular advances have been made in the field of lymphomas, contributing to refining diagnostic criteria of several diseases, to upgrade entities previously defined as provisional and to identify new entities. This process has resulted in two recent classifying proposals of lymphoid neoplasms, the International Consensus Classification (ICC) and the 5th edition of the WHO classification (WHO-HAEM5). In this paper, we review and compare the two classifications in terms of diagnostic criteria and entity definition, with focus on mature B-cell neoplasms. The main aim is to provide a tool to facilitate the work of pathologists, hematologists and researchers involved in the diagnosis and treatment of lymphomas.