How effective and safe is idelalisib combined with rituximab in a real-world practice for the management of chronic lymphocytic leukemia?

This study evaluated the effectiveness and safety of idelalisib (Zydelig) combined with rituximab (Rituxan) in the treatment of patients with chronic lymphocytic leukemia (CLL) in a real-world setting. The data supported the effectiveness of this regimen in routine practice for these patients.

Idelalisib (IDL) is an approved targeted therapy for relapsed or refractory CLL (r/r) CLL. It is given with immunotherapy rituximab (R). The combination of IDL-R has been shown to improve survival without disease worsening compared to rituximab alone in clinical trials. However, long-term IDL-R use has been restricted due to side effects. Since gaining approval for use, there has not been available data on the safety and effectiveness of the IDL-R regimen outside of the clinical trial setting. 

The study included 110 patients with CLL. 27 patients had received IDL-R as front-line therapy (group 1) and 83 patients had received treatment after a relapse (group 2). The average follow-up period was 30.2 months.

Overall, 88.2% of patients responded to treatment. 96.3% of the patients in group 1 responded to treatment compared to 85.5% in group 2. Response to treatment lasted for 32.8 months on average. The average survival without cancer worsening was 29.6 months. After 3 years, 56.1% of all patients were alive.

63% of patients in group 1 had stopped treatment due to side effects, compared to 44.6% of those in group 2. Serious side effects were lower respiratory tract infection or pneumonia, diarrhea, and inflammation of the lining of the colon.

The study showed that IDL-R is an effective treatment option in routine clinical practice for patients with CLL. The authors suggested that careful management may be needed, especially for younger patients or those in the front-line setting due to an increased risk of side effects.

This study was based on medical records. Some information might have been missing. The study was funded by Gilead Sciences Ltd., the developers of idelalisib.