The U.S. Food and Drug Administration (FDA) recently approved an expansion to prescribing information for the kinase inhibitor Imbruvica (ibrutinib), based on improved survival, safety, and efficacy data from studies in people with chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). The drug is approved by the FDA for the treatment of CLL/SLL, Waldenström’s macroglobulinemia, and Mantle cell lymphoma.
Data came from the Phase 3 RESONATE-2 clinical trial, which evaluated Imbruvica versus chlorambucil in treatment-naïve CLL/SLL patients ages 65 and older. The new label also reflects updated safety and efficacy data from the Phase 3 HELIOS clinical trial, which investigated Imbruvica in combination with bendamustine and rituximab, versus placebo plus those standard treatments, in patients with relapsed or refractory CLL/SLL.
RESONATE-2, which was the basis for Imbruvica’s approval as a first-line treatment of CLL patients in March 2016, found a statistically significant reduction (56%) in the risk of death in those taking Imbruvica compared to those taking a comparative drug after a median follow-up of 28.1 months. HELIOS trial results found improvement in progression-free survival (PFS) and overall response rate (ORR).
Results from the trials demonstrated that the Imbruvica regimen was linked to an 80% reduction in the risk of disease progression or death versus placebo. Median progression-free survival was also not reached in the Imbruvica group, while it was found to be 13.3 months in the placebo arm.
“The update helps to affirm the established efficacy, safety and tolerability of this therapy for the treatment of patients with CLL/SLL, both as a monotherapy or in combination with other agents,” Jan Burger, MD, an associate professor at the Department of Leukemia in The University of Texas MD Anderson Cancer Center’s Division of Cancer Medicine, said in a press release. Dr. Burger was lead investigator for the RESONATE-2 study. “It reflects the growing body of clinical evidence supporting this therapy as a potential treatment option for people living with CLL/SLL.”
Imbruvica is a first-in-class, oral, once-daily therapy that inhibits a protein, Bruton’s tyrosine kinase (BTK). This protein is a key signaling molecule in the B-cell receptor signaling complex, with impact on the survival and spread of malignant B cells. The drug blocks signals alerting malignant B-cells to multiply and spread.