Clinical Trials for Patients with Hairy Cell Leukemia

Clinical trials are carefully controlled research studies, and are necessary to develop and study ways to improve treatment and quality of life for patients with hairy cell leukemia. Clinical trials may be available for patients at any stage of HCL. Your eligibility for a clinical trial depends on a variety of factors such as whether you have HCL or HCL variant, your stage of disease, your age and gender and the type of treatment, if any, that you’ve already received.

We encourage you to discuss clinical trials with your doctor and healthcare team to consider the availability of a trial for your unique diagnosis, treatment history and needs.

As you review your options with your doctor, you will want to understand the purpose and length of a given clinical study; potential benefits and risks; costs of the study, including any charges you will be responsible for; your responsibilities and limitations during the trial, including travel requirements; and whether you will continue to see your own doctor during the trial.

Clinical Trials at hcl centers of excellence

We encourage you to review and discuss the ongoing clinical trials below with your doctor to identify whether there may be a study that could work for you. We will continue to add information about new studies as they are available. You are welcome to contact us at for additional information.

Cladribine and rituximab for patients with once-relapsed HCL

Purpose: To achieve complete remission without minimal residual disease, to prevent relapse.

Eligibility: HCL after one course of either pentostatin or cladribine. Need for retreatment due to abnormal blood counts, growing lymph nodes, painful spleen or infections.

Contacts at the National Institutes of Health (NIH):

Multicenter phase 2 study of the bruton’s tyrosine kinase inhibitor pci-32765 (ibrutinib) for treatment of relapsed hairy cell leukemia

Purpose: Determine the response rate of HCL after 32 weeks of single-agent ibrutinib treatment.

Eligibility: Adults with classical hairy cell leukemia or the hairy cell leukemia variant who require treatment.  Classical hairy cell leukemia patients must have received prior purine nucleoside analogue treatment (cladribine or pentostatin) or be unable to receive it.  Anyone with the hairy cell leukemia variant is eligible whether or not they have had prior treatment.

Participating Sites: The Ohio State University, National Institutes of Health Clinical Center, Karmanos Cancer Institue, Mayo clinic, and M D Anderson Cancer Center

Contact at The Ohio State University:

Rituximab combined with pentostatin or bendamustine for HCL variant (HCLv) or multiple relapsed HCL

Purpose: To achieve complete remission without minimal residual disease, to prevent relapse.

Eligibility: HCLv with or without prior treatment, or HCL with at least 2 prior treatments; Treatment required due to abnormal blood counts, growing lymph nodes, painful spleen or infections.

Contacts at the National Institutes of Health:

Combining vemurafenib cobimetinib and/or obinutuzumab for treatment of HCL

Purpose: Combine the BRAF inhibitor, vemurafenib, with the MEK inhibitor cobimetinib and/or the anti-CD20 antibody obinutuzumab to achieve deep, complete remission for HCL patients who relapse after completing standard chemotherapy treatment with cladribine or pentostatin. 

Eligibility: Eligible patients in Italy must meet one of the following criteria: 1) they have already received two courses of chemotherapy (with cladribine or pentostatin) or one course of chemotherapy that was followed by an early relapse (within 2 years of treatment); or 2) they cannot receive chemotherapy treatment (e.g., due to age (>70 years), active infections or important comorbidities); or 3) they experienced major toxicities due to chemotherapy. 

Contact at the University of Perugia, Italy:

A Phase II study of the BRAF inhibitor, vemurafenib, plus obinutuzumab in patients with previously untreated HCL

Purpose: Although HCL patients experience excellent responses to initial purine analog based chemotherapy (e.g., cladribine or pentostatin), relapses are not uncommon and the disease remains incurable. There is a need for novel therapies for HCL patients. To this end, we are conducting a phase II clinical trial combining the BRAF inhibitor, vemurafeinb, and anti-CD20 antibody, obinutuzumab, in patients with previously untreated HCL to achieve a deeper molecular response with more favorable side effect profile and durable remissions.

Eligibility: Adult patients, ≥18 years old, with histologically confirmed classical HCL and who have not received any prior therapy for the disease. Patients must meet the treatment initiation criteria as defined by ANC ≤1.0, OR Hgb ≤10.0 OR PLT ≤100K. Patients must have at least one of these indications.

Contact at Memorial Sloan-Kettering Cancer Center:

  • Jae Park, MD 212-639-4048

You may want to explore, a registry of federally and privately supported clinical trials in the United States and around the world. This website is a service of the U.S. National Institutes of Health (NIH). Once on the website, you can enter “hairy cell leukemia” in the “Condition or Disease” box and click “Search” for a list of relevant trials. You can also specify a “Country” to narrow your search.