Not enough elderly patients are included in drug trials targeting some of their most common illnesses, a new study by FDA researchers concludes.

Examining cohort age demographics in 166 clinical trials comprising 229,558 subjects, FDA pharmacologist S.W. Johnny Lau and colleagues found studies of type 2 diabetes and non-small cell lung cancer (NSCLC) included very few subjects age 75 years or older. And studies of nonvalvular atrial fibrillation (NVAF) stroke prevention, depression, insomnia, heart failure and osteoporosis included almost no patients who were 80 and older, they wrote in the journal JAMA Network Open.

“Underrepresentation of the oldest adults existed during evaluation of new drugs and biologics, yet the older adults may represent significant proportions of the treatment population,” wrote Lau et al.

The trials in the study supported approvals for 44 new drug applications and biologics license applications from 2010-2019. The applications covered drugs for seven conditions commonly affecting older people, including depression, heart failure, insomnia, NSCLC, NVAF stroke prevention, osteoporosis, and type 2 diabetes. The authors compared the ages of enrolled subjects to the age prevalence associated with the disorders.

Overall, half of the participants were younger than 65 and just 8 percent were older than 80. Depression trials enrolled the youngest cohort and trials for prevention of stroke in patients with NVAF the oldest.

For example, people age 75 and older make up 43 percent of NSCLC cases but comprised just 7.3 percent of the NSCLC study cohorts. There was also an over-representation of younger subjects. “Individuals who were ages 40-64 years were overrepresented … 58 percent for the clinical trial data vs. 21.5 percent for the prevalence data.”

People older than 75 or 80 were underenrolled in the studies of type 2 diabetes, heart failure and NSCLC. And people older than 80 were barely represented. In the depression studies, for example, the vast proportion of subjects (93 percent) were age 15-64 years. Of the 7,977 enrolled, just 13 were older than 80.

Age-related factors like polypharmacy — the simultaneous use of multiple drugs by a single patient for one or more conditions — multimorbidity and organ dysfunction contribute to the low enrollment of elderly subjects in clinical trials, and these are difficult problems to overcome. Closing the gaps in enrollment of older adults “will require engagement of multiple stakeholders, including researchers and scientific societies, regulatory bodies, healthcare providers, older adults and caregivers, and healthcare payers,” the authors wrote.

“Although there are long-standing FDA guidances that the clinical trial participants pool should represent the population that will ultimately receive the product, there continues to be room for improvement. A clinical trial ecosystem needs to be developed to acquire and provide this information so that it can be used to optimize prescribing at the time of introduction of drugs into clinical care,” said Lau and colleagues.

Read the full JAMA Network Open study here: https://bit.ly/3Tlpass.