MAYWOOD, IL – A landmark study co-authored by a Loyola Medicine oncologist has found that a newer targeted drug is significantly more effective than standard therapy for treating elderly patients with chronic lymphocytic leukemia (CLL).
The drug, ibrutinib, also has fewer side effects and is more convenient than the standard treatment, the study found. Loyola oncologist Scott Smith, MD, PhD is among the senior authors of the study, published in the New England Journal of Medicine.
"This represents a paradigm change in how we will treat elderly patients with CLL," Dr. Smith said. "Ibrutinib should become the new standard of care."
Dr. Smith is a professor in the division of hematology/oncology, department of medicine of Loyola Medicine and Loyola University Chicago Stritch School of Medicine. He was executive officer of the Alliance for Clinical Trials in Oncology, which coordinated the study, and was responsible for the execution of the study.
CLL, a disease of the immune system, is the most common form of leukemia in adults. It affects mainly older adults, with the average age of diagnosis around 70. The risk is higher in men.
Until now, the standard treatment has been a combination of a chemotherapy drug (bendamustine) that kills cancer cells and an immunotherapy drug (rituximab) that suppresses the immune system. The regimen requires a patient to come in three times a month for infusions and an injection.
A newer treatment involves ibrutinib. The targeted drug attacks cancer cells without damaging normal cells, thus causing fewer side effects. Ibrutinib works by blocking signals that stimulate cancer cells to grow uncontrollably. The regimen requires a patient to simply take a pill once a day.
The study enrolled 547 CLL patients (67 percent male) at 219 centers in the United States and Canada. All were older than 65, with a median age of 71. Researchers randomly assigned patients to receive one of three regimens: the standard treatment of bendamustine plus rituximab; ibrutinib alone; or ibrutinib plus rituximab. After two years, 87 percent of patients receiving ibrutinib alone were alive without any disease progression, compared with 74 percent of patients who received bendamustine plus rituximab. There was no significant difference between patients receiving ibrutinib alone and those receiving ibrutinib plus rituximab.
About 17 percent of patients who received ibrutinib alone experienced an irregular heartbeat called atrial fibrillation. But overall, the drug caused fewer side effects than the standard treatment, Dr. Smith said.
Additional studies of ibrutinib are underway in CLL patients younger than 65, Dr. Smith said.
The study is titled "Ibrutinib Regimens versus Chemoimmunotherapy in Older Patients with Untreated CLL." First author is Jennifer Woyach, MD, of Ohio State University.
As an academic medical center, Loyola is able to offer hundreds of cancer clinical trials, giving patients access to many new cancer drugs and therapies that are not available at most hospitals. Therapies under study at Loyola include targeted therapy, immunotherapy and new forms of surgery, chemotherapy and radiation.