At the 2012 ASH Annual Meeting, researchers also reported preliminary results for ibrutinib in diffuse large B-cell lymphoma, follicular lymphoma, and multiple myeloma.
A multicenter phase II study in 70 heavily pretreated patients with relapsed or refractory diffuse large B-cell lymphoma in two genetically distinct subtypes—the activated B-cell subtype and the germinal center subtype—found an overall response rate of 23%.1 Responses were primarily in the activated B-cell subtype (41%), including five complete responses and seven partial responses. Investigators suggested that the use of the acivated B-cell molecular subtype could serve as a biomarker for enrichment of patients in future trials.
In relapsed follicular lymphoma, a phase I study in 16 heavily pretreated patients showed the overall response rate to be 44%, including three complete responses.2 In optimally dosed patients, response rates rose to 55% and median progression-free survival was 13.4 months.
In relapsed/refractory multiple myeloma, signals of biologic and clinical activity were observed for ibrutinib.2 Reductions in paraprotein ≥ 50% were seen in three patients, and one patient responded when dexamethasone was added. Decreases in several biomarkers of bone metabolism, angiogenesis, and chemotaxis were associated with treatment. ■
1. Wilson WH, Gerecitano J, Goy A, et al: The Bruton’s tyrosine kinase inhibitor, ibrutinib (PCI-32765), has preferential activity in the ABC subtype of relapsed/refractory de novo diffuse large B-cell lymphoma: Interim results of a multicenter, open-label, phase 2 study. 2012 ASH Annual Meeting. Abstract 686. Presented December 10, 2012.
2. Fowler N, Advani R, Sharman J, et al: The Bruton’s tyrosine kinase inhibitor ibrutinib (PCI-32765) is active and tolerated in relapsed follicular lymphoma. 2012 ASH Annual Meeting. Abstract 156. Presented December 9, 2012.
The investigational agent ibrutinib demonstrated “unprecedented” single-agent activity in relapsed or refractory mantle cell lymphoma, according to the lead author of an international phase II study reported at the Annual Meeting of the American Society of Hematology (ASH).1
Martin Dreyling, MD, Professor of Medicine at Ludwig Maximilians University in Munich and Coordinator of the European Mantle Cell Lymphoma Network, commented on the data emerging for ibrutinib in lymphoma. “Ibrutinib is the molecule of the year at ASH,” he told The ASCO Post.
“With other molecular ...