Targeting BTK with ibrutinib in relapsed or refractory mantle-cell lymphoma

N Engl J Med. 2013 Aug 8;369(6):507-16. doi: 10.1056/NEJMoa1306220. Epub 2013 Jun 19.

Abstract

Background: Bruton's tyrosine kinase (BTK) is a mediator of the B-cell-receptor signaling pathway implicated in the pathogenesis of B-cell cancers. In a phase 1 study, ibrutinib, a BTK inhibitor, showed antitumor activity in several types of non-Hodgkin's lymphoma, including mantle-cell lymphoma.

Methods: In this phase 2 study, we investigated oral ibrutinib, at a daily dose of 560 mg, in 111 patients with relapsed or refractory mantle-cell lymphoma. Patients were enrolled into two groups: those who had previously received at least 2 cycles of bortezomib therapy and those who had received less than 2 complete cycles of bortezomib or had received no prior bortezomib therapy. The primary end point was the overall response rate. Secondary end points were duration of response, progression-free survival, overall survival, and safety.

Results: The median age was 68 years, and 86% of patients had intermediate-risk or high-risk mantle-cell lymphoma according to clinical prognostic factors. Patients had received a median of three prior therapies. The most common treatment-related adverse events were mild or moderate diarrhea, fatigue, and nausea. Grade 3 or higher hematologic events were infrequent and included neutropenia (in 16% of patients), thrombocytopenia (in 11%), and anemia (in 10%). A response rate of 68% (75 patients) was observed, with a complete response rate of 21% and a partial response rate of 47%; prior treatment with bortezomib had no effect on the response rate. With an estimated median follow-up of 15.3 months, the estimated median response duration was 17.5 months (95% confidence interval [CI], 15.8 to not reached), the estimated median progression-free survival was 13.9 months (95% CI, 7.0 to not reached), and the median overall survival was not reached. The estimated rate of overall survival was 58% at 18 months.

Conclusions: Ibrutinib shows durable single-agent efficacy in relapsed or refractory mantle-cell lymphoma. (Funded by Pharmacyclics and others; ClinicalTrials.gov number, NCT01236391.)

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Agammaglobulinaemia Tyrosine Kinase
  • Aged
  • Aged, 80 and over
  • Drug Resistance, Neoplasm
  • Female
  • Humans
  • Lymphocyte Count
  • Lymphoma, Mantle-Cell / drug therapy*
  • Lymphoma, Mantle-Cell / mortality
  • Male
  • Middle Aged
  • Protein Kinase Inhibitors / adverse effects
  • Protein Kinase Inhibitors / therapeutic use*
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Pyrazoles / adverse effects
  • Pyrazoles / therapeutic use*
  • Pyrimidines / adverse effects
  • Pyrimidines / therapeutic use*
  • Recurrence
  • Survival Analysis

Substances

  • PCI 32765
  • Protein Kinase Inhibitors
  • Pyrazoles
  • Pyrimidines
  • Protein-Tyrosine Kinases
  • Agammaglobulinaemia Tyrosine Kinase
  • BTK protein, human

Associated data

  • ClinicalTrials.gov/NCT01236391