In a nutshell
This study wanted to look at the effect of ibrutinib (Imbruvica) on white cell count (immune cells) in patients with chronic lymphocytic leukemia. Researchers found that increases in white cell count during ibrutinib treatment were normal and did not indicate poor outcomes in these patients.
Chronic lymphocytic leukemia (CLL) is a cancer of the bone marrow. This often leads to abnormal numbers of immune cells, such as an increased lymphocyte count. Ibrutinib is a treatment that targets certain proteins on cancer cells. It can also cause an increased lymphocyte count in patients with CLL. It is still unknown if this effect of ibrutinib in patients with CLL can predict disease progression, which can lead to early treatment stoppage.
Methods & findings
This study included patients from 2 trials. 136 patients were treated with ibrutinib for the first time (group 1). The other trial (group 2) evaluated 195 patients relapsed or unresponsive to other treatments treated with ibrutinib.
High lymphocyte count after ibrutinib was seen in 77 (57%) patients in group 1. This lasted for 12 weeks and resolved in 95% of these patients. In group 2, 133 (69%) patients had increased lymphocyte count after ibrutinib. This lasted for 14 weeks and resolved in 94% of these patients.
In group 1, response to treatment was similar in patients with high lymphocyte count (92%) and those without (91%). In group 2, the response rate was 89% in patients with high lymphocyte count and 83% in those without. Survival without cancer growing or spreading was also similar in patients with high lymphocyte count and those without, in both groups.
The bottom line
The study concluded that raised lymphocyte count during ibrutinib treatment was a common and safe side effect. The authors suggested that this side effect does not influence outcomes and does not require treatment interruption.
Published By :
Leukemia & lymphoma
Oct 04, 2018