Wilmot Research Leads to Therapy for Vulnerable Hairy Cell Leukemia Patients

Feb. 23, 2021
Clive Zent, MD
Clive Zent, M.D, hairy cell leukemia expert

A Wilmot Cancer Institute expert in hairy cell leukemia has discovered a new way to treat patients with this rare disease who have other medical problems and therefore do not qualify for clinical trials or standard therapies.

Nine patients were running out of options, but Clive Zent, M.D., led an observational study that showed a targeted, non-chemotherapy drug regimen for hairy cell leukemia can put them into long-term remission. Importantly, the treatment did not suppress the patients’ immune systems — an advantage during the coronavirus pandemic and the need to avoid infections.

The journal Leukemia Research reported Zent’s results. It is the first clinical publication in the field to address this specific problem, Zent said, and provides data on how to treat patients who have serious co-morbidities or cannot take standard therapies. However, additional research is needed to determine the most effective dose of the drug regimen before it can be used in general clinical practice.

Hairy cell leukemia is a rare lymphoma, with only about 1,100 cases diagnosed annually in the U.S. It is caused by slow growth of abnormal white cells called B-lymphocytes, which accumulate in the spleen, lymph nodes and bone marrow.

The five-year survival rate is about 90 percent, but only when the patient responds to standard treatment. The new treatment is designed for those who could not receive or had failed standard therapy.

Researchers tested the nine patients for genetic mutations associated with the disease and discovered they were all positive for the BRAF V600E mutation. Vemurafenib, a drug known to target this mutant protein, was administered in a low dose for a short time, often in combination with rituximab, an antibody that targets B-lymphocytes. Data from other trials and case reports have previously shown vemurafenib to be effective in chemotherapy resistant sub-populations of hairy cell leukemia patients.

Jeremiah Moore, Pharm.D., BCOP, is a pharmacy specialist at Wilmot who worked closely with Zent to monitor the patients and their treatment responses. Moore is first author and co-designer of the study. Zent is a professor of Medicine, Hematology/Oncology, at the University of Rochester Medical Center.

Zent operates one of only 10 Hairy Cell Leukemia Foundation-designated Centers of Excellence  in the U.S. Funding for the study was provided by the Hairy Cell Leukemia Foundation (HCFL) and the Cadregari Endowment Fund at the University of Rochester.