Ibrutinib as Treatment for Patients With Relapsed/Refractory Follicular Lymphoma: Results From the Open-Label, Multicenter, Phase II DAWN Study

PurposeThe Bruton's tyrosine kinase inhibitor ibrutinib has demonstrated clinical activity in B-cell malignancies. The DAWN study assessed the efficacy and safety of single-agent ibrutinib in chemoimmunotherapy relapsed/refractory follicular lymphoma (FL) patients.MethodsDAWN was an open-label, single-arm, phase II study of ibrutinib in patients with FL with two or more prior lines of therapy. Patients received ibrutinib 560 mg daily until progressive disease/unacceptable toxicity. The primary objective was independent review committee–assessed overall response rate (ORR; complete response plus partial response). Exploratory analyses of T-cell subsets in peripheral blood (baseline/cycle 3) and cytokines/chemokines (baseline/cycle 2) were performed for available samples.ResultsBetween March 2013 and May 2016, 110 patients with a median of three prior lines of therapy were enrolled. At median follow-up of 27.7 months, ORR was 20.9% (95% CI, 13.7% to 29.7%, which did not meet the 18% lower-bound threshold fo...