Hairy cell leukaemia
Hairy cell leukaemia is a rare, slow B-cell leukaemia with a single defining mutation (BRAF V600E) that is unusually curable: one week of a purine analogue puts most people into remission for years, and BRAF drugs rescue those who relapse.
Classic hairy cell leukaemia (HCL) is a mature B-cell neoplasm with a distinctive morphology and immunophenotype (CD11c, CD25, CD103, CD123, annexin A1) and BRAF V600E in essentially all cases (Tiacci 2011); the variant HCL-v lacks BRAF V600E, is CD25-negative, and behaves worse (often MAP2K1-mutant). Patients present with pancytopenia, splenomegaly and infections.
Purine analogues (cladribine or pentostatin) give complete remission in 80-90% with a single course, and adding rituximab (concurrent or delayed) deepens responses and achieves MRD negativity in most (Chihara et al.). Relapse is treated with a second purine analogue course plus rituximab; BRAF inhibition (vemurafenib ± rituximab) gives durable remissions in multiply relapsed disease (Tiacci 2021, NEJM), and BRAF+MEK combinations are an option. Moxetumomab pasudotox (anti-CD22 immunotoxin) was approved in 2018 and withdrawn commercially in 2023. Ibrutinib has modest activity. Overall survival is now close to age-matched controls.
State of the art today
- One week of cladribine remains one of the most effective single treatments in oncology.
- BRAF V600E is universal in classic HCL; vemurafenib-rituximab produces MRD-negative remissions in most relapsed patients without chemotherapy.
Show survival figures (1)
Averages across everyone diagnosed, often years ago. Your stage, subtype, age, fitness and the treatment you receive matter more than the average, and the numbers are improving quickly.
- Life expectancy is near normal; the residual problems are infection during induction and the aggressive variant.
Hairy cell leukaemia causes about 1,000-1,200 cases per year in the US (~2% of leukaemias); median age ~55, 4:1 male.
Where the cases are
No country-level case numbers. This cancer is not mapped to a GLOBOCAN site.
Cladribine (5-7 days) or pentostatin, with rituximab concurrent or delayed (improves MRD-negative CR).
Vemurafenib + rituximab (or dabrafenib-trametinib); ibrutinib; moxetumomab pasudotox where still available; clinical trial.
Subtypes & biomarkers
top- Classic HCL (BRAF V600E)
- HCL variant (BRAF-wild-type, CD25-negative, MAP2K1 mutations)
- IGHV4-34 HCL (poor risk)
- BRAF V600E (IHC VE1, PCR, ddPCR)
- Flow cytometry : CD11c, CD25, CD103, CD123
- MRD by flow or BRAF ddPCR
- IGHV4-34 usage
- MAP2K1 mutations (variant)
Target prevalence in this cancer
- 1958Bouroncle describes 'leukemic reticuloendotheliosis'
- 1984Interferon alfa: first effective therapy
- 1990Cladribine: durable remissions after one course (Piro, NEJM)
- 2011BRAF V600E found in all classic HCL (Tiacci, NEJM)
- 2015Vemurafenib active in relapsed HCL
- 2018Moxetumomab pasudotox approved
First CD22 immunotoxin; withdrawn from the US market in 2023 for commercial reasons.
- 2021Vemurafenib + rituximab: chemo-free durable remissions (NEJM)
Open problems
- Variant HCL and IGHV4-34 disease respond poorly to purine analogues.
- Infection risk during induction neutropenia.
- Whether MRD eradication should be a treatment goal.
Trials
topRecruiting now (live from ClinicalTrials.gov)
Country and place are remembered in this browser only. A postcode is sent to OpenStreetMap's Nominatim service to find coordinates when you press the button; nothing else leaves your device.
Expert centres
topCentres linked to this cancer in OnCo
- The Ohio State University Comprehensive Cancer Center – James Cancer Hospital and Solove Research InstituteColumbus, OH, USNCI comprehensivevia Ibrutinib
- Wellcome Sanger InstituteHinxton, GBvia BRAF
Questions to ask
topQuestions to ask your oncologist about Hairy cell leukaemia
Newly diagnosed
- What is my exact diagnosis, stage, and grade, and which tests established them?Why: Everything else follows from an accurate stage and subtype.
- Which biomarkers have been tested on my tumour (for example BRAF V600E, Flow cytometry: CD11c, CD25, CD103, CD123, MRD by flow or BRAF ddPCR, IGHV4-34 usage, MAP2K1 mutations), and what were the results?Why: These results decide eligibility for targeted therapy, immunotherapy, and trials.
- Which subtype is my cancer, and does that change the recommended treatment?Why: Recognised subtypes for this cancer include Classic HCL, HCL variant, IGHV4-34 HCL.
- Is germline (inherited) genetic testing recommended for me or my family?Why: Inherited variants can change treatment and matter for relatives.
First line, symptomatic
- For my situation (first line, symptomatic), which of the standard options do you recommend and why?Why: Guideline options include: Cladribine (5-7 days) or pentostatin, with rituximab concurrent or delayed (improves MRD-negative CR).
- Am I a candidate for Cladribine, Rituximab, and what side effects should I expect?Why: Knowing the expected toxicities helps you plan work, family, and supportive care.
Relapse after >2 years
- For my situation (relapse after >2 years), which of the standard options do you recommend and why?Why: Guideline options include: Repeat purine analogue + rituximab.
- Am I a candidate for Cladribine, Rituximab, and what side effects should I expect?Why: Knowing the expected toxicities helps you plan work, family, and supportive care.
Early relapse or refractory
- For my situation (early relapse or refractory), which of the standard options do you recommend and why?Why: Guideline options include: Vemurafenib + rituximab (or dabrafenib-trametinib); ibrutinib; moxetumomab pasudotox where still available; clinical trial.
- Am I a candidate for Vemurafenib, Rituximab, Dabrafenib + trametinib or related drugs, and what side effects should I expect?Why: Knowing the expected toxicities helps you plan work, family, and supportive care.
Any stage
- Are there clinical trials I could join, for example of Vemurafenib, Dabrafenib + trametinib?Why: Trials are how the next standard of care is set; asking early keeps options open.
- Would a second opinion at a high-volume centre change anything, and can you help arrange it?Why: Rare or high-stakes decisions benefit from a centre that treats many similar patients.
- What supportive care (symptom control, nutrition, exercise, mental health, financial help) is available from the start?Why: Supportive care improves quality of life and helps patients complete treatment.
- I read that “Variant HCL and IGHV4-34 disease respond poorly to purine analogues”. How does that affect my plan?Why: Open problems are where trials and second opinions matter most.
- I read that “Infection risk during induction neutropenia”. How does that affect my plan?Why: Open problems are where trials and second opinions matter most.
Print this page for your appointment (your browser's print command). These prompts are for discussion; your clinical team knows your case.
Direct links plus the targets, companies, and technologies of this cancer's products.
technologies
6targets
5drugs
7companies
5pathways
1terms
1Latest papers
topQuery for this cancer: (TITLE:"Hairy cell leukaemia" OR ABSTRACT:"Hairy cell leukaemia") AND (treatment OR therapy OR trial OR survival OR diagnosis). Results are unfiltered search hits about Hairy cell leukaemia, not a curated reading list.