Toxicities Increased for Patients Receiving CLL Therapy in the Real-World
A recent study found that while treatment outcomes for a chronic lymphocytic leukemia (CLL) therapy are comparable in clinical trials and the real-world setting, adverse events are increased in the latter.
Results of the study will be presented at the 59th Annual American Society of Hematology Meeting and Exposition (December 9-12, 2017; Atlanta, GA).
While ibrutinib (Imbruvica) is approved for all lines of therapy in CLL in the United States and Europe, front-line studies of the drug have mostly enrolled older patients with low-risk disease. This population of patients are not representative of patients seen in clinical practice, thus signifying that treatment patterns and outcomes may differ in clinical trials and the real-world.
Anthony R Mato, MD, Center for CLL, University of Pennsylvania, Abramson Cancer Center, and colleagues studied the use of front-line ibrutinib in patients with CLL treated in the real-world. A total of 391 patients (85.5% of whom were high-risk) treated with ibrutinib across 19 academic and community sites were retrospectively analyzed. Researchers examined demographics, prognostic factors, dosing, discontinuation rates, adverse events, overall response rate (ORR), and survival outcomes.
The primary endpoint was progression-free survival (PFS), measured from the time of ibrutinib initiation until CLL progression, death, or last follow-up.
Results of the study showed that ORR was comparable in clinical trials to the real-world; PFS and overall survival in high-risk populations were similar to that in low-risk older populations.
However, adverse events profiles were different between the treatment settings. Patients in the real-world were more likely to have dose-reductions (17%) or necessitate dose interruption (median time off therapy, 12 days). High-risk populations were also more likely to initiate therapy at a lower dose than the FDA-indicated dosage.
Researchers noted that toxicity was the most common reason for treatment discontinuation, but many patients did not require immediate treatment following discontinuation, which indicated sustained response.
“Encouraging responses were observed following ibrutinib discontinuation with no clear standard treatment approach and limited use of CIT in these chemo-naïve patients,” authors of the study wrote. “This underscores the need for trials studying best strategy post-ibrutinib.”—Zachary Bessette