
How Does IMBRUVICA® Work?
IMBRUVICA® (ibrutinib) is an Oral, Once-Daily MCL Medication That Works Differently Than Chemotherapy1
One of the most common initial treatments for mantle cell lymphoma (MCL) is chemotherapy. If chemotherapy doesn't work for you or stops working, you have other options.2
- IMBRUVICA® blocks a protein in B cells called Bruton’s tyrosine kinase, or BTK. BTK signaling is needed for abnormal B cells to multiply and survive1
- By blocking BTK, IMBRUVICA® may help move abnormal B cells out of their nourishing environments in the lymph nodes, bone marrow, and other organs1,3
Because of how IMBRUVICA® works, it may cause side effects. A relationship between how IMBRUVICA® works and why it helps to treat certain diseases has not been clearly identified.1
You may experience changes in your white blood cell count
After starting IMBRUVICA®, your doctor will monitor your blood cell counts.1 Your lab results may show an increase in lymphocytes, a type of white blood cell. This is called lymphocytosis and can occur with IMBRUVICA® treatment. In the absence of other signs and symptoms, this increase may not necessarily mean your condition is worsening.4
In a clinical trial of 111 patients, lymphocytosis occurred in 33% (1 out of 3) of patients taking IMBRUVICA®. The onset of isolated lymphocytosis occurred during the first few weeks of IMBRUVICA® therapy and resolved by a median* of 8 weeks.1
Talk to your doctor about what your test results mean.
*Median is the middle number in a group of numbers that are arranged from lowest to highest. For example, in the group of numbers 1-11, 6 is the median.

References:
- IMBRUVICA® (ibrutinib) Prescribing Information.
- Leukemia & Lymphoma Society. Mantle cell lymphoma facts: No. 4. http://www.lls.org/sites/default/files/file_assets/FS4_MCL_Facts_2018-final.pdf. Accessed April 26, 2019.
- de Rooij MF, Kuil A, Geest CR, et al. The clinically active BTK inhibitor PCI-32765 targets B-cell receptor- and chemokine-controlled adhesion and migration in chronic lymphocytic leukemia. Blood. 2012;119(11):2590-2594.
- Cheson BD, Byrd JC, Rai KR, et al. Novel targeted agents and the need to refine clinical end points in chronic lymphocytic leukemia. J Clin Oncol. 2012;30(23):2820-2822.
- Genetics Home Reference. What genes are related to isolated growth hormone deficiency? https://ghr.nlm.nih.gov/condition/isolated-growth-hormone-deficiency#genes. Accessed April 26, 2019.