Targeted Therapy for CLL: Imbruvica®
~ Dr. Kumudini Rao
Researchers are developing newer drugs that specifically target the changes inside cells that cause them to become cancerous. Unlike standard chemotherapy agents, which work by attacking rapidly growing cells in general (including cancer cells), these drugs attack one or more specific targets on or in cancer cells.
Ibrutinib (Imbruvica®) is a targeted drug that can be used to treat chronic lymphocytic leukemia (CLL) if at least one other treatment has already been tried. It blocks the activity of a protein called a kinase that tells the leukemia cells to divide and helps them survive. This drug has been shown to help when CLL is hard to treat, for example, if there are chromosome 17 deletions or if CLL has come back after other treatments.
In a multicenter, open-label, phase 3 study, 391 patients with relapsed or refractory CLL or SLL were randomly assigned to receive daily ibrutinib or the anti-CD20 antibody ofatumumab. The primary end point was the duration of progression-free survival, with the duration of overall survival and the overall response rate as secondary end points.
RESULTS: At a median follow-up of 9.4 months, ibrutinib significantly improved progression-free survival; the median duration was not reached in the ibrutinib group (with a rate of progression-free survival of 88% at 6 months), as compared with a median of 8.1 months in the ofatumumab group. Ibrutinib also significantly improved overall survival. At 12 months, the overall survival rate was 90% in the ibrutinib group and 81% in the ofatumumab group. The overall response rate was significantly higher in the ibrutinib group than in the ofatumumab group (42.6% vs. 4.1%, P<0.001).
We are very well versed with targeted therapy in solids tumors including breast, colon, lung, melanoma. We have been using most of available targeted agents in lymphoma, leukemia with excellent outcomes.