A new study has found that combining ibrutinib and rituximab could help cancer patients with chronic lymphocytic leukemia (CLL). The results of the study were presented this week at the 54th annual meeting of the American Society of Hematology (ASH).

“This is a patient population with a great need for more targeted therapies,” said Dr. Jan Burger, lead author of the study and an associate professor at the MD Anderson’s Department of Leukemia. “Many CLL patients, especially those with indolent or non-aggressive disease, do well on the standard treatment of chemotherapy and antibodies. But for a certain subset of high-risk patients, treatment often fails, and remissions, if they are achieved, are short.”

According to the National Cancer Institute, CLL is the most common type of adult leukemia. The disease is more common in men than women, and the average age of diagnosis is 72. The side effects of current treatments can be harsh: though chemotherapy combinations have improved the survival rate for CLL, many CLL deaths are from secondary cancers caused by treatment.

“When we looked at how well the high-risk patients were doing on ibrutinib – even though it was a small number – we saw a great opportunity to find out if combining the two drugs would have a positive impact on these patients,” said Burger.

The study looked at forty patients with high-risk CLL. After four months, 38 of the patients saw no disease progression, while one died from an unrelated infectious complication and one withdrew from the study due to oral ulcers. 20 of the patients were evaluated at three months, showing that 17 of them had a partial remission and three of them had a partial remission. This 85% response rate came with “well tolerated” side effects, including fatigue, pneumonia, insomnia, bone aches, and neutropenia (low white blood cell counts).

“Although this study has a short follow-up time, we are encouraged by the fact that the vast majority of patients are responding and are able to continue on treatment,” said Burger.