Progression-free survival was significantly better when patients with relapsed or refractory mantle-cell lymphoma were treated with oral ibrutinib than with intravenous temsirolimus, based on results from 280 patients in an international, randomized, open-label phase III trial.
Study subjects had undergone one or more previous rituximab-containing chemotherapy regimens to receive intravenous temsirolimus or oral ibrutinib at a daily dose of 560 mg.
Compared with temsirolimus, ibrutinib resulted in a 57% reduction in the risk of disease progression or death at a median follow-up of 20 months. Median progression-free survival – the trial’s primary endpoint – was 14.6 months for the ibrutinib group and 6.2 months for the temsirolimus group.
Ibrutinib was also better tolerated, with 68% of patients having grade 3 or higher treatment-emergent adverse events as compared to 87% of patients in the temsirolimus group, despite a median 4-fold longer treatment duration for the ibrutinib group than the temsirolimus group. Additionally, 6% of patients discontinued ibrutinib because of adverse events versus 26% in the temsirolimus group, reported Dr. Martin Dreyling of Klinikum der Universität in Munich, Germany, and his associates.
Courtesy Wikimedia Commons/Nephron/Creative Commons
Intermediate magnification micrograph of mantle cell lymphoma of the terminal ileum.
Based on results of the Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) questionnaire, ibrutinib was associated with greater and more rapid improvements, and also with less worsening in lymphoma symptoms, as measured by the lymphoma subscale of the FACT-Lym (Lancet. 2016;387:770-78).
Ibrutinib, a first-in-class oral inhibitor of Bruton’s tyrosine kinase, is approved in the United States and the European Union at a dose of 560 mg per day for patients with mantle cell lymphoma who have received at least one previous line of therapy.
The mammalian target of rapamycin (mTOR) inhibitor temsirolimus is approved in the European Union for relapsed or refractory mantle-cell lymphoma, but does not have FDA approval for this indication.
The study, funded by Janssen, is ongoing. Future research, the investigators say, should examine ibrutinib-based combination approaches for patients with relapsed or refractory mantle-cell lymphoma and in front-line therapy.
Dr. Dreyling reported grants and personal fees from Janssen and Pfizer outside of the study. Several other authors reported grants from Janssen during the study and financial ties to the company.