The U.S. Food and Drug Administration has approved ibrutinib (Imbruvica) for the first-line treatment of patients with chronic lymphocytic leukemia (CLL).1
“This approval represents a significant leap forward for patients diagnosed with CLL who may want to consider an alternative first-line treatment to traditional chemotherapy,” said Michael Severino, MD, executive vice president, research and development and chief scientific officer at AbbVie.
The recommended dose is 420 mg (three 140 mg capsules) taken orally once daily.
Approval is based on findings from the multicenter, open-label, phase 3 RESONATE-2 trial, which assessed the efficacy and safety to ibrutinib compared with that of chlorambucil in 269 treatment-naïve patients with CLL or small lymphocytic leukemia (SLL) who were 65 years or older.
Results showed that ibrutinib significantly reduced the risk of disease progression or death by 84% vs chlorambucil (HR, 0.161; 95% CI, 0.091 – 0.283). Median progression-free survival had not yet been reached in the ibrutinib group and was 18.9 months (95% CI, 14.1 – 22.0) for chlorambucil.
Ibrutinib was also associated with a significant improvement in overall response rate compared with chlorambucil (82.4% vs 35.3%; P < .0001). Five of the patients in the ibrutinib arm achieved a complete response vs 2 in the chlorambucil arm.
“The progression-free survival data seen in these previously untreated CLL patients are strong and encouraging,” said lead study investigator Jan Burger, MD, PhD, associate professor in the Department of Leukemia at The University of Texas MD Anderson Cancer Center in Houston, TX. “This is especially important for first-line CLL patients, when considering the safety profile. This treatment represents another option for these patients.”
In terms of toxicity, the safety of ibrutinib was consistent with previously reported studies. The most common adverse events associated with ibrutinib were diarrhea, musculoskeletal pain, cough, and rash.
For the study, participants were randomly assigned to receive ibrutinib, a first-in-class Bruton’s tyrosine kinase inhibitor, at a dose of 420 mg orally daily until disease progression or unacceptable toxicity, or chlorambucil on days 1 and 15 of each 28-day cycle for up to 12 cycles.
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Ibrutinib is also indicated for the treatment of patients with mantle cell lymphoma who have received at least 1 prior therapy and those with Waldenström’s macroglobulinemia.
- Imbruvica® (ibrutinib) approved by U.S. FDA for the first-line treatment of chronic lymphocytic leukemia [news release]. North Chicago, IL: Abbvie; March 4, 2016. http://abbvie.mediaroom.com/2016-03-04-IMBRUVICA-ibrutinib-Approved-by-U-S-FDA-for-the-First-line-Treatment-of-Chronic-Lymphocytic-Leukemia. Accessed March 4, 2016.