Based on the results of a recent clinical trial presented at ASH 2018 and discussed in CONQUER magazine in December 2018 (https://conquer-magazine.com/categories/leukemia), in January 2019 the FDA approved the combination of the oral Bruton’s tyrosine kinase inhibitor Imbruvica (ibrutinib; from Pharmacyclics) plus the CD20-directed cytolytic antibody Gazyva (obinutuzumab; from Genentech), for use as the first treatment in older adults (aged 65 or older) with chronic lymphocytic leukemia (CLL) or with small lymphocytic lymphoma (SLL). Imbruvica was already approved as a single agent for different treatments, including for adults with CLL or SLL, with or without 17p deletion.
This new approval was based on a phase 3 clinical trial that included 229 patients with newly diagnosed CLL or SLL who were aged 65 years or older, and who had additional medical conditions, such as kidney disease and/or 17p deletion or TP53 gene mutation. The patients received Imbruvica plus Gazyva or chemotherapy plus Gazyva.
After almost 3 years of treatment, the patients who received the combination of Imbruvica plus Gazyva had a much longer period without disease progression than those who received chemotherapy plus Gazyva. In fact, the average period without disease progression was not yet reached with Imbruvica plus Gazyva, meaning patients are continuing to respond to treatment without disease progression, compared with only 19 months in the comparison group.
The most common side effects with Imbruvica plus Gazyva were an increased risk for infection (neutropenia), platelet deficiency, rash, diarrhea, musculoskeletal and joint pain, bruising, cough, infusion-related reaction, and bleeding (hemorrhage).