Hairy Cell Leukemia: Where Are We in 2023?

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