Examining outcomes for CLL patients who discontinued ibrutinib

This study examined outcomes for patients with chronic lymphocytic leukemia (CLL) who discontinued treatment with ibrutinib (Imbruvica). Researchers found that patients who discontinued due to progressive CLL had better survival compared with those who had disease transformation.

Ibrutinib is a Bruton tyrosine kinase inhibitor that is used as first-line therapy for CLL as well as salvage therapy after other lines of treatment have failed. Tyrosine kinase inhibitors are a type of targeted therapy that block the action of enzymes called tyrosine kinases. Ibrutinib can be administered alone or in combination with other drugs such as chemotherapies.

Studies have shown that about 10 to 20% of patients receiving ibrutinib-based treatment discontinue treatment after an average of 1 year. Reasons include side effects, disease progression, or transformation to a more aggressive form of CLL. Patients who discontinue ibrutinib often have poor outcomes. However, more long-term studies are needed.

The records of 320 CLL patients treated with ibrutinib were analyzed. Treatment outcomes were followed for an average of 38 months.

90 patients (28%) discontinued ibrutinib-based treatment. Of these, 10 were receiving first-line treatment. 80 patients had relapsed CLL or were not responding to other lines of treatment. The average time to discontinuation was 15 months.

Reasons for treatment discontinuation included side effects (32%), progression (21%), disease transformation (10%), and other causes (31%).

44% of patients who discontinued treatment were alive at 38 months. Average overall survival (time from treatment until death from any cause) was 33 months for patients who discontinued treatment due to side effects. It was 16 months for disease progression, 2 months for disease transformation, and 11 months for other causes. 42% of patients with disease progression responded to subsequent therapy.

Researchers reported cases of ibrutinib discontinuation during therapy. Patients who discontinued due to progressive CLL had better survival compared with those who had disease transformation.

Larger studies are needed to confirm these results.