CHICAGO — Older adults, especially those older than 75 years, are underrepresented in clinical trials of cancer drugs, according to study findings presented at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting.
Researchers at the FDA analyzed the age-related enrollment of cancer patients into clinical trials supporting registration of new drugs or new indications approved by the agency from 2005 to 2015. The study population included 224,766 cancer patients supporting 105 drug applications. Patients were categorized by age group: younger than 65 years, 65 to 69, 70 to 74, 75 to 79, and 80 years or older. The age distributions of the US cancer population were derived from the Surveillance, Epidemiology, and End Results Program and the National Cancer Institute for 2013 based on 2010 US Census data.
Patients younger than 65 years had a cancer incidence of 44% in 2013 yet made up 60% of clinical trial participants during the 10-year study period, Harpreet Singh, MD, reported. Patients aged 65 to 69 years had a cancer incidence of 14% in 2013 and made up 17% of clinical trial participants. The 2013 cancer incidence among patients aged 75 to 79 years and 80 years and older was 13% and 16%, respectively, but they made up only 8% and 4% of clinical trial participants, respectively.
According to the investigators, restrictive eligibility criteria should be re-evaluated so as not to exclude older adults. “In terms of patient selection, we encourage sponsors to include assessment tools in their registration trials to help better identify which older patients may be better suited for clinical trials,” Dr Singh told listeners.
Dr Singh cited statistics from ASCO Cancerlinq to put into context a broader issue with clinical trial enrollment. Approximately 1.7 million people are diagnosed with cancer in the United States each year, but only 3% are enrolled in clinical trials.
“We also know that we have an issue with generalizability of clinical trial results, not only with age, but more recent analyses have shown that patients in the real world versus clinical trials have more comorbidities, including organ dysfunction, and are more diverse in terms of race and ethnicity,” she said.
1. Singh H, Kanapuru B, Smith C, et al. FDA analysis of enrollment of older adults in clinical trials for cancer drug application: a 10-year experience by the U.S. Food and Drug Administration. Oral presentation at: 2017 American Society of Clinical Oncology Annual Meeting; June 2-6, 2017; Chicago, IL.