Study: Older adults underrepresented in trials of drugs they may regularly use

Regulatory NewsRegulatory News | 19 October 2022 |  By 

Older adults are not well represented in clinical trials of drugs and biologics they may regularly use, according to recent research published in JAMA Network Open.
“Data on safety and efficacy of medications across the entire older age span are important to appropriately care for this growing older population,” S. W. Johnny Lau, PhD, with the Office of Clinical Pharmacology, Office of Translational Sciences at the Center for Drug Evaluation and Research (CDER) in the US Food and Drug Administration (FDA), and colleagues wrote in their study. “Although there are long-standing FDA guidances that the clinical trial participant pool should represent the population that will ultimately receive the product, there continues to be room for improvement.”
Lau and colleagues performed a cross-sectional study that examined the proportion of older adults in trials of drugs and biologics approved under new drug applications (NDAs) and biologics license applications (BLAs) between 2010 and 2019. In total, 166 efficacy trials with 229,558 participants were identified for 44 NDAs and biologics that had indications for nonvalvular atrial fibrillation (NVAF) stroke prevention (77,281 participants), type 2 diabetes (66,512 participants), heart failure (25,918 participants), osteoporosis (25,454 participants), non-small cell lung cancer (NSCLC) (22,427 participants), depression (7,977 participants) and insomnia (3,989 participants).
The trial participants’ ages were then compared with the age groups of the prevalent population in the US with each condition using data from one or more sources such as the Health and Retirement Study, US Census, National Health and Nutrition Examination Survey, National Health Interview Survey and the Surveillance, Epidemiology and End Results database.
The results of the analysis showed about half of participants overall were under 65 years old, 8% were 80 years or older, and women comprised 46.8% of participants in all trials. Participants in trials with treatment indications for depression were the youngest at median 45 years old, while the oldest participants were enrolled in trials for NVAF stroke prevention at median 72 years old.
Using a participation to prevalence ratio (PPR) benchmark range of 0.8–1.2 to gauge adequate representation of a particular age group, the researchers found trials with participants having ages ranging between 60–75 years old were “in proportion to or in greater proportion than the US prevalent population,” while PPRs for the participants 75 years or 80 years or older were not proportional to the prevalent population in type 2 diabetes (PPR, 0.20), heart failure (PPR, 0.19) and NSCLC (PPR, 0.17). In trials evaluating a drug or biologic as a treatment for depression, individuals 80 years or older comprised 0.1% of the trial population, and “suggest underrepresentation of older age groups in the clinical trials” despite a PPR analysis being unfeasible due to lack of comprehensive prevalence data in that age group.
Lau and colleagues noted more work is needed to enroll older trial participants, and cited issues like polypharmacy, multimorbidity and organ dysfunction as potential explanations for low enrollment these participants. “Closing the gaps in clinical trial enrollment of older adults will require engagement of multiple stakeholders, including researchers and scientific societies, regulatory bodies, health care providers, older adults and caregivers, and health care payers,” the authors said.
“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,” they concluded.
JAMA Netw Open Lau et al.


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