Understanding IMBRUVICA® (ibrutinib) treatment-related lymphocytosis

Lymphocytosis is an increase in the number of lymphocytes in the blood. Therapies that interfere with trafficking and adhesion of malignant lymphocytes by disrupting B-cell signaling can result in treatment-related lymphocytosis.1,2

​Isolated asymptomatic lymphocytosis may be due to the mechanism of action of IMBRUVICA® and may not be a sign of disease progression.1,3
 

Treatment-related lymphocytosis occurred in 66% of patients treated with single-agent IMBRUVICA® across the CLL/SLL registration studies4

  • Lymphocytosis is defined as ≥50% increase from baseline and above absolute lymphocyte count of 5,000/mcL
  • In the CLL/SLL registration studies, the onset of isolated lymphocytosis occurred during the first month of IMBRUVICA® therapy and resolved by a median of 14 weeks (range, 0.1 to 104 weeks)
  • Lymphocytosis occurred in 7% of patients treated with IMBRUVICA® + BR vs 6% with placebo + BR
  • Lymphocytosis occurred in 7% of patients treated with IMBRUVICA® + obinutuzumab vs 1% with chlorambucil + obinutuzumab