Targeted therapies give new hope for those with chronic lymphocytic leukemia (CLL). Each year, an estimated 2,165 Canadians are diagnosed with the disease, which represents 35 percent of all types of leukemia across the country. While CLL is a type of leukemia, it is essentially the same disease as small lymphocytic lymphoma, and is treated the same way as a lymphoma. Lymphoma Canada includes CLL under its umbrella of care.

What is CLL?

CLL is a slow growing blood cancer that causes the bone marrow, the tissue in the body where blood cells are produced, to make an overabundance of B lymphocytes, a type of white blood cell. It is diagnosed most often through blood tests that are done routinely during an annual medical exam. Those with this genetic disease may not experience symptoms early on, but can develop anemia, fatigue, infections or bleeding.

The average age of onset of this genetic disease is 72 years of age, but it can appear in patients in their 40s, 50s, and 60s as well. As Robin Markowitz, President and CEO of Lymphoma Canada explains, “CLL is a disease of aging. Cells become less hardy and more inclined to break down easily, making them more likely to turn and become cancerous.” Unfortunately, CLL is not curable. For most, current treatments work initially, but only temporarily.

“The new treatments are less invasive and easier to tolerate. That’s what makes them so great for the older patients.”

Overcoming treatment challenges

While the amount of time differs for each patient, it is common for patients to relapse after treatments, and with each subsequent relapse, remission periods become shorter. Given that the average age of diagnosis is 72, many patients are not well enough, or have co-existing medical conditions, and are not good candidates for chemotherapy, one of the traditional treatments for CLL. That has made the disease more difficult to treat. Up until recently, the options available to those with relapsed CLL have been very limited.

Even if a patient can undergo chemotherapy, there are other potential problems such as accessibility to clinics and hospitals that offer it – most located in major urban centres. Patients in more rural communities or with transportation issues may not be able to get treatment.

Researchers have been successful in creating easy-to-take oral drugs. The introduction and approvals of: idelalisib for patients with recurring CLL and follicular lymphoma (FL), a slow-growing blood cancer that originates in the lymph system, and ibrutinib for recurring CLL; represent a new standard in care. In clinical trials, 75 to 80 percent of patients responded positively to these targeted therapies.

New frontiers in CLL research

“The new treatments are less invasive and easier to tolerate,” says Markowitz. “That’s what makes them so great for the older patients for many reasons. More treatment options will provide new hope for many CLL and FL patients.”

Both idelalisib and ibrutinib work in a similar way. The drugs act by turning off the signals going to blood cells that make them become cancerous. The primary difference between the two is that they each address different enzymes that are part of a complicated cellular network.

As a hematologist, Dr. Carolyn Owen, also Assistant Professor, Division of Hematology and Hematological Malignancies, Foothills Medical Centre in Calgary, has witnessed firsthand the advancement of CLL treatments. “It’s an area with a lot of changes happening and exciting new research,” she says. “There is clear evidence that targeted therapies are effective for CLL.”

Dr. Owen adds: “It’s amazing how quickly these new drugs have gone from scientific theory about how they will work, to human trials, then to approvals from Health Canada and the FDA. The rapidity of the process is a testament to how well they have worked.”