Addition of Ibrutinib to Initial Treatment for Younger Patients With CLL
Posted: Tuesday, August 20, 2019
In reportedly the first study to assess the activity and safety of ibrutinib in combination with fludarabine, cyclophosphamide, and rituximab (FCR) in previously untreated, younger patients with chronic lymphocytic leukemia (CLL), the addition of ibrutinib to treatment with FCR appears to be a “promising” option with a manageable safety profile. These findings are from an open-label, single-arm, phase II trial published in The Lancet Haematology.
“The proportion of patients who achieved undetectable minimal residual disease in bone marrow with ibrutinib plus FCR is, to our knowledge, the highest ever published in patients with chronic lymphocytic leukemia unrestricted by prognostic marker status,” stated Matthew S. Davids, MD, MMSc, of the Dana-Farber Cancer Institute, Boston, and colleagues. “These data represent a first step towards establishing a new standard of care with curative potential for this patient population.”
The study enrolled 85 patients, with a median age of 55 years, who had previously untreated CLL. After initial treatment with ibrutinib plus FCR, patients who responded to therapy continued to receive ibrutinib maintenance for up to 2 years. At that point, patients with undetectable minimal residual disease in bone marrow were able to discontinue treatment.
A complete response and undetectable minimal residual disease in bone marrow 2 months after the last cycle of ibrutinib plus FCR were achieved by 33% of patients, compared with a 20% historical value with FCR alone (P = .0035). A best response of undetectable minimal residual disease in bone marrow was achieved by 84% of patients during the study.
As for safety, the most common all-grade toxic effects were hematologic, including thrombocytopenia (74%), neutropenia (62%), and anemia (49%). Grade 3 or 4 nonhematologic adverse events included grade 3 atrial fibrillation in three patients and grade 3 Pneumocystis jirovecii pneumonia in two patients.
Disclosure: The study authors’ disclosure information may be found at thelancet.com.