According to a new study published in the journal The Lancet Oncology, ibrutinib alone may be safe and effective for the first- or second-line treatment of patients with high-risk chronic lymphocytic leukemia (CLL) with TP53 aberrations.
For this single-arm, phase 2 study, researchers at the National Institutes of Health Clinical Center in Bethesda, Maryland, enrolled 47 patients with active CLL with deletion 17p13.1 and four patients with a TP53 aberration without a 17p13.1 deletion. Of those, 35 had previously untreated disease while 16 had relapsed or refractory CLL.
All patients received ibrutinib 420mg orally once daily in 28-day cycles until disease progression or unacceptable toxicity. Results showed that among the 33 evaluable previously untreated patients at 24 weeks, 97% (95% CI: 86-100) achieved an objective response. One patient had progressive disease.
Among the 15 evaluable patients with relapsed or refractory disease, 80% (95% CI: 52-96) achieved an objective response. In regard to safety, 24% of patients experienced severe neutropenia, 14% had severe anemia, and 10% experienced severe thrombocytopenia. Six percent of patients experienced grade 3 pneumonia and 2% had grade 3 rash.
The findings suggest that ibrutinib alone should be considered as an option for patients with high-risk CLL with TP53 aberrations for first- or second-line treatment.
The authors investigated the safety and activity of ibrutinib in previously untreated and relapsed or refractory CLL with TP53 aberrations. The activity and safety profile of single-agent ibrutinib in CLL with TP53 aberrations is encouraging and supports its consideration as a novel treatment option for patients with this high-risk disease in both first-line and second-line settings.