FDA Commissioner Stephen Hahn referenced the differences in how COVID-19 is affecting various populations in the U.S. to highlight the need for greater diversity in clinical trials as the agency released its final guidance “Enhancing the diversity of clinical trial populations – eligibility criteria, enrollment practices and trial designs” Nov. 9. The disparities in how different populations are being impacted by the pandemic “illustrates why we must encourage developers of any medical product such as treatments or vaccines for COVID-19 – as well as medical products more broadly – to endeavor to include diverse populations to understand their risks or benefits across all groups,” Hahn said. Issued in draft form last year before the coronavirus emerged, the guidance advises sponsors on increasing enrollment of underrepresented populations in their trials by taking steps to broaden the eligibility criteria through inclusive trial practices, trial designs and methodological approaches. The guidance addresses the need for diversity when it comes to demographic characteristics such as sex, race, ethnicity, age and residency, as well as non-demographic characteristics including organ dysfunction, comorbid conditions, rare diseases, disabilities and weight. “To further promote and protect public health, it is important that people who are in clinical trials represent the populations most likely to use the potential medical product,” Hahn said. The guidance recognizes that there are justifiable medical reasons for excluding certain patients from early trials. However, “as data on excretory and metabolic pathways and drug-drug interactions become available during the drug development program, allowing appropriate dose adjustments, there should be fewer exclusions related to concomitant medications or comorbidities,” according to the guidance. “Similarly, as the safety experience with a product increases, eligibility criteria should be broadened to include more medically complex participants; any remaining exclusions should be justified.” The guidance also cautions against using commonly accepted eligibility criteria across trials that exclude certain populations from trial participation without strong clinical or scientific justification. The FDA has been pushing for greater trial diversity for several years. But despite those efforts, “challenges to participation in clinical trials remain, and certain groups continue to be underrepresented in many clinical trials,” according to the guidance. A report released Nov. 9 by the FDA’s Center for Drug Evaluation and Research showed that trial inclusion varies by location. For instance, of the 102,596 U.S. participants in trials from 2015 to 2019, 56% were women, 16% were Black or African American, 2% were Asian and 21% were 65 years and older. However, the report, which summarized CDER’s drug snapshots for the five-year period, found that of the 190,170 participants in trials in the rest of the world, 49% were women, 2% were Black or African American, 16% were Asian and 37% were 65 years and older.