Adrian Wiestner, MD, PhD, National Institutes of Health, National Heart, Lung, and Blood Services, discusses findings from the phase III HELIOS trial, which explored the addition of ibrutinib to bendamustine and rituximab for patients with relapsed/refractory chronic lymphocytic leukemia.
Adrian Wiestner, MD, PhD, Senior Investigator, Laboratory of Lymphoid Malignancies, National Institutes of Health, National Heart, Lung, and Blood Services, discusses findings from the phase III HELIOS trial, which explored the addition of ibrutinib (Imbruvica) to bendamustine and rituximab (BR) for patients with relapsed/refractory chronic lymphocytic leukemia (CLL).
In the study, 578 patients with relapsed/refractory CLL were treated with BR plus ibrutinib (n = 289) or placebo (n = 289). BR was administered for a maximum of 6 cycles. After this point, patients could continue to receive ibrutinib until disease progression.
At a median follow-up of 17.2 months, the median progression-free survival (PFS) was not reached in the ibrutinib arm compared with 13.3 months with BR alone (HR = 0.203; 95% CI, 0.150-0.276; P <.0001). The objective response rate was 82.7% in the ibrutinib arm versus 67.8% in the control group (P <.0001).
These were exciting results, Wiestner notes, since the addition of a targeted therapy improved outcomes seen with chemotherapy. The dramatic improvement in PFS was achieved by maintaining treatment with ibrutinib, Wiestner believes, an approach that could be labeled either maintenance or continuation therapy.
Researchers are now questioning whether another therapy needs to be added to an agent that targets the B-cell signaling pathway, Wiestner suggests. It is unclear whether combination approaches have significantly improved outcomes over single-agent ibrutinib. As a result, the treatment paradigm in CLL could shift toward the use of monotherapy, as opposed to combination strategies.