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Janssen Biotech, Inc.
Health Canada has granted conditional approval for the BTK inhibitor ibrutinib (Imbruvica) to treat patients with relapsed or refractory mantle cell lymphoma (MCL).
This approval was based on data from a phase 2 trial in which ibrutinib conferred an overall response rate of 68% in patients with relapsed/refractory MCL.
For ibrutinib to gain full approval, Health Canada must receive additional data confirming the drug provides a clinical benefit.
Ibrutinib was first approved in Canada in November 2014 for patients with chronic lymphocytic leukemia (CLL), including those with 17p deletion, who have received at least one prior therapy, or for the frontline treatment of patients with CLL with 17p deletion. For this use, ibrutinib was issued marketing authorization without conditions.
Now, Health Canada has issued ibrutinib conditional marketing authorization for the treatment of relapsed/refractory MCL. This decision was based on data from the phase 2 PCYC-1104 trial, which was presented at ASH 2012 and published in NEJM in August 2013.
The study included 111 MCL patients who had received at least one prior therapy. The primary endpoint of the study was overall response rate according to the revised International Working Group criteria for non-Hodgkin lymphoma.
The overall response rate was 68%, with a complete response rate of 21% and a partial response rate of 47%. With a median follow-up of 15.3 months, the median response duration was 17.5 months.
The estimated progression-free survival was 13.9 months, and the overall survival was not reached. The estimated rate of overall survival was 58% at 18 months.
Common nonhematologic adverse events included diarrhea (50%), fatigue (41%), nausea (31%), peripheral edema (28%), dyspnea (27%), constipation (25%), upper respiratory tract infection (23%), vomiting (23%), and decreased appetite (21%). The most common grade 3, 4, or 5 infection was pneumonia (6%).
Grade 3 and 4 hematologic adverse events included neutropenia (16%), thrombocytopenia (11%), and anemia (10%). Grade 3 bleeding events occurred in 5 patients.
Eight patients (7%) had an adverse event that led to treatment discontinuation.
Sixteen patients (14%) died during the trial, 12 due to disease progression and 4 due to an adverse event. Two patients died of pneumonia, 1 from sepsis, and 1 from a cardiac arrest that was not considered drug-related.
Ibrutinib is co-developed by Cilag GmbH International (a member of the Janssen Pharmaceutical Companies) and Pharmacyclics LLC, an AbbVie company. Janssen Inc. markets ibrutinib as Imbruvica in Canada.
