When Moderna Inc. realized that clinical trials for the company's experimental coronavirus vaccine were not diverse enough, executives pumped the brakes, even as the world eagerly awaited any good news on a preventative treatment for COVID-19.

"As you can imagine, it was not an easy decision to slow down, but it was the right decision," Moderna CEO Stéphane Bancel said during a third-quarter earnings call in October.

The company, which was launched into the spotlight this year when it joined the pack of pharmaceutical industry behemoths leading the vaccine race, slowed down the COVE study examining the vaccine's effectiveness to better account for the high burden of disease among some populations and recruit more diverse populations.

Ultimately, the trial ended up at about 37% diverse populations, similar to the census of the U.S., including 6,000 Hispanics or Latinx participants and 3,000 Black or African American people out of 30,000 total.

"Our Phase 3 COVE study is representative of the many diverse populations that make up our nation, and by extension, many parts of the world. And many people could identify with our study and can find themselves in it," Chief Medical Officer Tal Zaks said.

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Pfizer Inc. similarly boosted enrollment in a late-stage trial for the pharmaceutical giant's coronavirus vaccine from 30,000 to 44,000 in part to improve diversity.

Even with the efforts of companies to add diverse patients into trials later, researchers from the University of California San Francisco found that Black patients were underrepresented in all six clinical trials for COVID-19 treatments conducted in the U.S. as of July. Most did not report racial and ethnic representation data at all. The examined trials included several investigating Gilead Sciences Inc.'s Veklury.

Unnecessary exclusion

While the COVID-19 pandemic has sharpened the pharmaceutical industry's focus on diversity, companies have not always sought diversity in clinical trials as a default. That led to approved drugs that could be less effective or even cause dangerous side effects in certain populations.

The U.S. Food and Drug Administration issued final guidance for the industry on how to improve diversity in clinical trials in November. The document recommends changes to requirements for trial exclusions, which can sometimes leave out large swaths of the populations who may have an underlying condition or tick some other box that can preclude them from participating in a clinical trial. Some of these exclusions could be obesity, pregnancy, women who are breastfeeding, people who are taking other medications and so on.

The FDA recommends that, once more data becomes available on a drug's safety, clinical trial investigators consider how to adjust medicine dosages for patients in more diverse populations so they may participate.

Patients can be excluded simply because they require accommodations, such as a translator or the flexibility to participate on evenings or weekends.

"Unnecessary exclusion of such participants may lead to a failure to discover important safety information about use of the investigational drug in patients who will take the drug after approval," the FDA said. The agency recommended eligibility requirements be expanded in later stages of the clinical trial process to better understand a drug's benefit-risk profile.

The industry recognizes the lack of diversity in clinical trials, and many companies have established programs to study the issue and commit to bringing in more communities to all parts of the drug development cycle.

"There is an urgent need to take on the inequities rooted in systemic racism that threaten health in communities of color across the U.S.," Johnson & Johnson CEO Alex Gorsky said as the world's largest healthcare company pledged $100 million for a new diversity program Nov. 17.

J&J's program will address racial and social injustice in public health, including one major initiative on increasing access and participation in clinical trials. The company has also committed to enrolling a diverse population in its COVID-19 vaccine trial and rolled out testing vans in Detroit and New Orleans to reach communities of color.

Bristol-Myers Squibb Co. has also put forward $100 million to extend the reach of clinical trials into underserved populations in the U.S. The money will go toward training 250 new racially and ethnically diverse clinical trial investigators and supporting 250 medical students to discover clinical research as a career opportunity.

"Diversity has a role to play in the entire lifecycle of therapeutic development, from the trial design and community engagement, to therapeutic efficacy and adoption," said Sandra Nichols, chair of the National Medical Fellowships board of directors, in Bristol Myers' Nov. 17 news release.

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