The FDA has approved an expansion to the prescribing information for ibrutinib (Imbruvica, Janssen/AbbVie) based on data supporting its use in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL).
The approved label now includes overall survival (OS) data from the phase 3 RESONATE-2 trial in treatment-naïve CLL/SLL patients 65 years of age or older. The updated label also contains clinical data from the phase 3 HELIOS trial, which investigated the use of ibrutinib in combination with bendamustine and rituximab (BR) compared with placebo plus BR in patients with relapsed or refractory CLL/SLL.
The updated findings from the RESONATE-2 study showed a statistically significant 56% reduction in the risk of death with ibrutinib compared with chlorambucil after a median follow-up period of 28.1 months (hazard ratio, 0.44). This analysis included 41% of patients in the chlorambucil arm who crossed over to receive ibrutinib therapy after disease progression. Results from the RESONATE-2 trial served as the basis for the March 2016 approval of ibrutinib as a first-line treatment for patients with CLL.
In addition, the first data from the HELIOS study on the use of ibrutinib in combination with other therapies were added to the ibrutinib label, highlighting the improvements in progression-free survival (PFS) and in the overall response rate (ORR) when using ibrutinib plus BR compared with placebo plus BR in patients with relapsed/refractory CLL/SLL. The results showed that the combination of ibrutinib and BR was associated with an 80% reduction in the risk of progression or death.
After reviewing the November 2015 supplemental new drug application for ibrutinib, the FDA expanded the drug’s indication to include the treatment of SLL patients with or without deletion of the chromosome 17p (del 17p). SLL is a slow-growing lymphoma that is similar to CLL.
RESONATE-2 was a randomized, open-label, international trial that evaluated the safety and efficacy of ibrutinib compared with that of chlorambucil in 269 treatment-naïve patients 65 years of age or older with CLL/SLL. The patients were randomly assigned to receive either oral ibrutinib 420 mg once daily until progression or unacceptable toxicity, or chlorambucil 0.5 to 0.8 mg/kg on days 1 and 15 of each 28-day cycle for up to 12 cycles, with an allowance for intrapatient dose increases of up to 0.8 mg/kg based on tolerability. The study’s primary endpoint was PFS, as assessed by an independent review committee. OS was a key secondary endpoint.
HELIOS was a randomized, double-blind, placebo-controlled, international study that evaluated the safety and efficacy of ibrutinib in combination with BR in 578 patients with relapsed/refractory CLL/SLL who had received at least one prior therapy. The patients were randomly assigned to receive either the combination of oral ibrutinib 420 mg once daily and six cycles of BR, or a matching regimen of oral placebo once daily and six cycles of BR, with ibrutinib or placebo continued until disease progression or unacceptable toxicity. The trial’s primary endpoint was PFS, and secondary endpoints included ORR and safety.
Source: Janssen; May 10, 2016.