Hope and Progress in hcl: Highlights from Our most recent Webinar
In our most recent Understanding Hairy Cell Leukemia (HCL) webinar, we had the honor of hosting Dr. Andritsos from the University of New Mexico, who shared a rich overview of Hairy Cell Leukemia (HCL). Her presentation brought clarity to the science of this rare blood cancer, while offering patients and families a hopeful look at current treatments and the promising innovations ahead.
What is Hairy Cell Leukemia (HCL)?
While classified as a “leukemia,” Dr. Andritsos clarified that HCL is biologically more similar to a lymphoma. The disease originates from a memory B cell — a type of immune cell that remembers past infections to protect the body in the future. A critical discovery in HCL biology is the BRAF V600E mutation, which is found in the majority of patients with HCL. This mutation drives uncontrolled cell growth and helps explain why HCL develops.
Notably, some patients may carry alternative mutations that require advanced genetic testing. For these cases, consultation at a Center of Excellence is highly recommended to ensure accurate diagnosis and tailored treatment.
Who is Affected by HCL?
HCL is rare, making up only about 2% of lymphomas. Most patients are diagnosed between the ages of 55 and 60, with men being affected more often than women. The condition is most common among Caucasians, with lower incidences in Asian, African, and Arab populations.
There are also potential links to environmental exposures, such as farming (with associated exposure to pesticides and herbicides), diesel fumes, or radiation. Some families appear to have multiple cases of HCL or related blood cancers, suggesting genetic or shared environmental factors.
Diagnosis and Testing
Patients are often diagnosed after routine blood work shows low counts or when they develop recurrent infections or experience spleen enlargement.
Key diagnostic tools include:
Bone marrow biopsy – provides a detailed picture of how cells appear and behave.
Immunophenotyping – identifies specific proteins on cell surfaces, confirming the presence of HCL.
BRAF mutation testing – essential for confirming diagnosis and guiding treatment.
Treatment Today: A True Success Story
Perhaps the most inspiring part of Dr. Andritsos’ talk was her review of the advances in treatment. Decades ago, patients diagnosed with HCL had limited options and an average survival of only four years. Today, thanks to medical breakthroughs, most patients can expect a near-normal life span.
1. Chemotherapy
Cladribine and Pentostatin remain the backbone of HCL treatment.
Both drugs produce high response rates (70–90% complete remission).
Many patients stay in remission for years, sometimes more than a decade.
The choice between them often depends on the physician's experience and the patient's preference.
2. Immunotherapy
Rituximab and Obinutuzumab target CD20, a protein on B cells.
When used alone, they can control disease in relapsed patients.
When combined with chemotherapy, they significantly improve the depth of remission.
A landmark study showed that Cladribine plus Rituximab upfront achieved 100% complete responses, with most patients achieving MRD (minimal residual disease) negativity — a strong predictor of long-term outcomes.
3. Targeted Therapies
BRAF inhibitors (such as Vemurafenib) directly target the driver mutation in most HCL patients.
They are beneficial for patients who cannot undergo chemotherapy, or for those needing urgent blood count recovery.
Responses are fast and effective, though typically shorter-lived than with chemotherapy.
Excitingly, combinations such as Vemurafenib plus Obinutuzumab are showing remission rates over 90%, offering a chemotherapy-free option.
4. Emerging Treatments
BTK inhibitors (already widely used in other B-cell cancers) are under study in HCL.
Venetoclax, a well-tolerated therapy, has shown early promise both alone and in combinations.
Cell-based therapies are on the horizon:
CAR-T therapy (teaching a patient’s own immune cells to fight HCL) is currently in early clinical trials.
Bispecific antibodies act like “off-the-shelf” CAR-T, linking T-cells to HCL cells to drive targeted killing.
These developments illustrate that treatment is no longer “one-size-fits-all.” Instead, care is becoming increasingly personalized, based on a patient's health, genetic profile, and treatment history.
Looking Ahead: Innovation and Hope
Dr. Andritsos emphasized that while HCL is not yet curable, today’s treatments offer remarkable durability, and tomorrow’s therapies may go even further. She pointed to the Hairy Cell Foundation’s research initiatives, which are funding cutting-edge work in CAR-T and bispecific therapies. This continued innovation reflects a bright horizon for patients living with HCL.
Key Takeaways
The main message of the webinar was one of hope and empowerment:
Effective therapies exist today that can provide long remissions and near-normal life expectancy.
Treatment decisions are personal and should strike a balance between timing, side effects, and long-term goals.
New therapies are expanding options, offering hope for patients who relapse or cannot tolerate chemotherapy.
Community and research are vital, with patient participation in registries and trials fueling progress for everyone.
Dr. Andritsos reminded patients: “There are highly effective therapies in hairy cell, and more to come.”
For the HCL community, this is a powerful reminder that no one faces this disease alone. With expert care, new therapies, and a supportive community, patients can look forward to living fuller, healthier lives.