In 2016, approximately 18,960 Americans were estimated to be diagnosed with chronic lymphocytic leukemia (CLL), and 4660 were estimated to die from the disease. The overall estimated 5-year survival rate of CLL in the United States in 2016 was 82.6%. Despite this, the outcomes in patients with this type of cancer who have specific genetic features, such as deletion (del)17p, are less positive when they receive conventional chemoimmunotherapy, such as the combination of fludarabine and cyclophosphamide or bendamustine plus rituximab.
In the past 3 years, several new treatments have been approved by the FDA for the treatment of treatment-naïve patients with CLL, including obinutuzumab (Gazyva), and ibrutinib (Imbruvica). Using the Flatiron’s provider network database, a real-world database that is focused on oncology, investigators assessed demographics and treatment patterns in the past few years.
The Flatiron database includes 230 oncology clinics and >1 million patients with cancer across the United States. As of June 2016, the cohort included 1033 patients diagnosed with CLL between 2011 and 2015 (median age, 70 years) from this database. The distribution of first-line therapies that were initiated between 2011 and 2013 was relatively constant. After the introduction to the market of obinutuzumab in 2014 and ibrutinib in 2015, the use of first-line obinutuzumab plus chemotherapy with chlorambucil increased from 7.2% in 2013 to 13.6% in 2015; similarly, the use of ibrutinib monotherapy or ibrutinib plus rituximab (Rituxan) increased from 9.8% in 2014 to 12.3% in 2015.
Of note, regimens containing fludarabine declined from 21.5% in 2011 to 8.4% in 2015. In addition, the use of rituximab monotherapy declined from 27.7% to 17.3%; and the use of bendamustine plus rituximab declined from 36.1% to 31.6%, and rituximab plus fludarabine plus cyclophosphamide from 4.6% to 2.2% between 2011 and 2015. The reasons that were associated with chlorambucil treatment, as monotherapy or in combination with another agent, versus chemoimmunotherapy included the patient’s older age and Rai stage. Approximately 20% of patients with del17p received treatment with ibrutinib.
From 2011 to 2015, real-world changes in the use of first-line treatment for CLL showed an increased use of newer agents, although no single standard of care was established. Second-line therapy reflects a similar degree of heterogeneity, and no uniform sequencing of therapies has been observed.