A study presented by Matthew S. Davids, MD, of Dana-Farber Cancer Institute, and colleagues at the 2021 American Society of Hematology (ASH) Annual Meeting & Exposition (Abstract 640) suggests that a 2.5-year regimen involving ibrutinib and chemoimmunotherapy may provide deep and lasting remissions for young, fit patients with chronic lymphocytic leukemia (CLL).
The findings update the early results of this study that were published in 2019 in The Lancet Haematology. At that time, the investigators examined the regimen in 85 patients with previously untreated CLL. Nearly all of the patients were in remission at the 16.5-month mark; the updated data confirm those benefits to be continuing now, at a median of 40.3 months.
“Patients with lower-risk CLL, which is marked by mutated IGHV genes, can gain long remissions from a 6-month regimen known as FCR—for the chemotherapy drugs fludarabine and cyclophosphamide and the antibody therapy rituximab. Patients who have higher-risk CLL, without an IGHV mutation, typically don’t receive the same durable benefit from FCR. They can do very well on ibrutinib, but need to continue it as a lifelong therapy, which can be particularly challenging for younger patients, given the ongoing risks and side effects associated with the drug,” said Dr. Davids.
Matthew S. Davids, MD
“Our study examined whether a time-limited course of ibrutinib given in combination with FCR can provide lasting remissions for patients with CLL regardless of whether they have the IGHV-mutated or -unmutated subtype,” he added.
The study enrolled 85 patients aged 65 years or younger with CLL. Forty-six of them had the more aggressive, unmutated IGHV subtype. Patients were treated with ibrutinib for 7 days followed by a combination of ibrutinib and FCR for up to 6 months. Patients then continued to receive ibrutinib alone for 2 additional years, and those who had no detectable leukemia cells in their bone marrow after the 2 years of treatment discontinued the therapy.
The new study found 99% of the patients to be alive at a median follow-up of 40.3 months, and 97% were alive with no worsening of their disease. Those figures are essentially unchanged from the early analysis of the study, which had a follow-up of 16.5 months.
The few patients whose disease did recur after the 2.5-year mark responded well to the resumption of ibrutinib therapy. The side effects of the combination therapy were largely manageable and were consistent with those associated with ibrutinib and FCR individually.
“We’re very encouraged about the potential of this therapy to generate long-term remissions in a broad population of younger patients with CLL,” Dr. Davids remarked. “For young patients, in particular, who hopefully have decades of life ahead of them, the prospect of a time-limited therapy that can have such durable impact without the need for ongoing treatment is very impactful.”
Disclosure: For full disclosures of the study authors, visit ash.confex.com.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.