The phase 3 trial of ibrutinib in combination with obinutuzumab met its primary endpoint of PFS for the treatment of patients with chronic lymphocytic leukemia and small lymphocytic lymphoma.
Ibrutinib (Imbruvica; Pharmacyclics/AbbVie, Janssen) — a Bruton tyrosine kinase inhibitor— is indicated for the treatment of patients with CLL, small lymphocytic lymphoma (SLL), Waldenström macroglobulinemia, previously treated mantle cell lymphoma, previously treated marginal zone lymphoma and previously treated chronic graft-versus-host disease.
The randomized, phase 3, open-label iLLUMINATE trial examined ibrutinib in combination with obinutuzumab (Gazyva, Genentech) compared with chlorambucil (Leukeran, Aspen Global) in combination with obinutuzumab for patients with previously untreated CLL or SLL.
Researchers randomly assigned patients to receive 420 mg ibrutinib continuously in combination with 1,000 mg IV obinutuzumab over six cycles or chlorambucil on days 1 and 15 of each cycle plus 1,000 mg IV obinutuzumab over six cycles.
PFS served as the primary endpoint. Secondary objectives included overall response rate and rate of minimal residual disease-negative responses.
According to the topline data, patients treated with ibrutinib plus obinutuzumab showed significantly improved PFS compared with patients treated with chemotherapy plus obinutuzumab.
“We are optimistic about the topline results from the iLLUMINATE study and the fact that Imbruvica plus obinutuzumab demonstrated marked improvement in PFS compared [with] obinutuzumab plus chlorambucil, a combination which is currently recommended by the National Comprehensive Cancer Network guidelines as a Category 1 treatment,” Danelle James, MD, MAS, head of clinical science at Pharmacyclics, said in a company-issued press release. “Since its introduction nearly 5 years ago, Imbruvica has been regarded as an important treatment option for patients with CLL/SLL. As well, we now have long-term, 5-year data in CLL. We are committed to researching the full potential of Imbruvica alone and in combination therapy across a range of B-cell blood cancers.”