The U.S. Food and Drug Administration (FDA) approved Imbruvica® (ibrutinib) in combination with Rituxan® (rituximab) for the initial treatment of adult patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL).
This review was conducted under Project Orbis, an initiative of the FDA Oncology Center of Excellence. For this application, the FDA is collaborating with the Australian Therapeutic Goods Administration, Health Canada, and Swissmedic.
The approval was based on results of the randomized, multicenter, open-label, actively-controlled E1912 trial that included 529 patients aged 70 years or younger with previously untreated CLL or SLL requiring systemic therapy. Patients were randomized 2:1 to receive ibrutinib 420 mg daily plus rituximab or fludarabine, cyclophosphamide, and rituximab.
Improved PFS with ibrutinib plus rituximab combo
There was a statistically significant improvement in progression-free survival (PFS; primary endpoint) for patients receiving ibrutinib plus rituximab (hazard ratio, 0.34; 95% CI, 0.22-0.52; P<0.0001). After a median follow-up of 37 months, median PFS was not reached in either cohort.
The most common adverse events associated with ibrutinib are thrombocytopenia, diarrhea, fatigue, musculoskeletal pain, neutropenia, rash, anemia, bruising, and nausea.