The latest studies and knowledge of the biological development of CLL cells have made it possible to design new drugs that target key molecules in the tumor-formation process.

Notable therapy approaches include:

• Ibrutinib: This drug inhibits the activity of the protein known as Bruton tyrosine kinase (BTK). It is administered orally and is tolerated well; the only side effects include diarrhea, fatigue, and pain in 45% of patients. It has been approved for use as monotherapy in patients who have undergone previous treatment.

• Idelalisib: This drug blogs another kinase, PI3K-δ. Clinical trials using the drug have shown results in patients when given in combination with rituximab. It is administered orally and the side effects are similar to those caused by ibrutinib though also include fever and abdominal pain.