By Will Boggs MD
NEW YORK (Reuters Health) - 25/4/2019
More men with advanced prostate cancer could benefit from immunotherapy with sipuleucel-T, according to researchers who found use of the drug was influenced by income and other factors.
"Prostate cancer is a disease that affects men of every race, income level, and in every part of the country," Dr. Megan V. Caram of the University of Michigan, in Ann Arbor, told Reuters Health by email. "Therefore, it is important that future work be done to investigate and identify disparities in use of therapies for prostate cancer. Identifying disparities is an important first step in working toward ensuring that treatment of a patient is based on their disease and not their income, race, the doctor that they see, or where they live."
Sipuleucel-T was approved by the U.S. Food and Drug Administration (FDA) in 2010 for use in metastatic castration-resistant prostate cancer (mCRPC) with minimal or no symptoms. It met with considerable initial skepticism as the first treatment of its kind, and its use has remained controversial despite evidence of its efficacy and safety.
Dr. Caram's team used data from the Clinformatics Data Mart Database to investigate patient, physician and regional factors associated with the adoption of sipuleucel-T.
Among the 7,272 men included in the study who received treatment for mCRPC, only 730 (10.0%) received sipuleucel-T, a fraction that increased from 0.6% in 2010, peaked at 15.1% in 2012, and then fell to 8.6% by 2016.
Most patients who received sipuleucel-T (69.0%) received it as first-line treatment, and most (68.2%) received subsequent therapies, the researchers report in JAMA Network Open, online April 19.
Nearly 10% of men treated with sipuleucel-T received it concurrently with other therapies, which is a non-evidence-based practice.
After adjusting for all other variables, Hispanic ethnicity and living in the Pacific region were independently associated with lower odds of receiving sipuleucel-T. Meanwhile, higher household income, having preferred provider organization insurance and being treated by a urologist were independently associated with higher odds of receiving the drug.
"In my opinion, the most important take-home point is the difference in use of sipuleucel-T at different income levels," Dr. Caram said. "This difference may be explained by an element of financial toxicity since many patients are still required to pay a significant amount out-of-pocket for this therapy. It's also possible that patients of lower income do not have access to centers that offer sipuleucel-T or are not being offered this therapy by their provider. Future studies will help elucidate the reason behind the income level difference."
"It is encouraging that we found most providers are using sipuleucel-T as first-line therapy in patients, the period of their disease when we would expect most patients would have the fewest symptoms and the lowest volume of their disease," she said. "However, it is still unknown when the optimal time will be and in which patients sipuleucel-T will provide the most benefit."
The study did not have commercial funding and the researchers report no conflicts of interest.
JAMA Netw Open 2019.