The US Food and Drug Administration (FDA) granted approval to ibrutinib plus rituximab for the treatment of patients with Waldenström macroglobulinemia (WM), a rare and incurable subtype of non-Hodgkin lymphoma.1
Ibrutinib — a Brutontyrosine kinase inhibitor — was previously granted a breakthrough therapy designation in 2015, becoming the first FDA-approved treatment available for this patient population. The expanded label now makes rituximab plus ibrutinib the first nonchemotherapy combination regimen approved for WM.
The FDA based its decision on data from the iNNOVATE phase 3 (ClinicalTrials.gov Identifier: NCT02165397) study, in which researchers randomly assigned 150 symptomatic patients with untreated or relapsed/refractory WM to receive ibrutinib plus rituximab or placebo plus rituximab.
After a median follow-up of 26.5 months, results showed that patients assigned to the ibrutinib group had a significant improvement in progression-free survival (PFS); the 30-month PFS rate was 82% in the ibrutinib arm compared with 28% among patients in the rituximab-only arm (hazard ratio [HR], 0.20; P< .001). Patients treated with ibrutinib also had an 80% reduction in relative risk of disease progression or death versus patients treated with rituximab only (HR, 0.20; 95% CI, 0.11-0.38; P< .0001).
The most frequently reported adverse events, occurring in more than 20% of patients, included bruising, musculoskeletal pain, hemorrhage, diarrhea, rash, arthralgia, nausea, and hypertension. Grade 3 to grade 4 infusion-related reactions were observed in 1% of patients.
- US FDA approves Imbruvica (ibrutinib) plus rituximab as first non-chemotherapy combination regimen for patients with Waldenström’s macroglobulinemia, a rare blood cancer [press release]. Horsham, PA: PR Newswire; August 27, 2018.https://www.prnewswire.com/news-releases/us-fda-approves-imbruvica-ibrutinib-plus-rituximab-as-first-non-chemotherapy-combination-regimen-for-patients-with-waldenstroms-macroglobulinemia-a-rare-blood-cancer-300702455.html . Accessed August 27, 2018.