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Photo: Bloomberg
Photo: Bloomberg

Covid-19 clinical trials aren’t very diverse and that’s a problem

The lack of minority participants in medical research has been a growing concern for years, as researchers have raised alarms about trials for cancer drugs and genetic research

Black and Latino people have suffered far more from the novel coronavirus than other races, yet so far they account for only a small fraction of participants in human clinical trials of treatments and vaccines.

That may complicate defeating Covid-19 since drug responses can be influenced by factors tied to race and ethnicity, such as genetics. More than that, diversity in research is necessary to understand the biological underpinnings of diseases that, for example, make some people more susceptible or responsive to treatment.

“Diversity is critically important," said John Beigel, an associate director for clinical research at the National Institute of Allergy and Infectious Diseases who has worked on multiple early-stage clinical trials for Covid-19. “You can’t have a public health intervention of this size without that."

While published trial data typically breaks down participants by demographics, the categories aren’t uniform. Still, it’s clear that most high-profile U.S. trials have been relying on largely White test pools. More than 70% of participants in a late-stage Gilead Sciences Inc. trial of Remdesivir, used to treat Covid-19, were White. Black people accounted for less than 12%. Early-stage vaccine trials of Moderna Inc.’s candidate that was led by NIAID were 89% White, and Pfizer Inc. and BioNTech SE’s joint candidate was tested on a group that’s 82% White. 

There’s no magic number for what the proper mix is for a trial. Test subjects should reflect the population that the treatment is meant for, and in a pandemic, that’s everyone. But since the virus has hit minority communities especially hard — in counties where the majority of residents are Black, the death rate has climbed to 3.5 times the national average, Bloomberg News analysis found — it’s especially important that trials ensure any treatment or vaccine works for them.

Of the five major Covid-19 clinical trials in the US reviewed by Bloomberg, just one reported significant diversity: A Remdesivir study by the NIAID that was led by Beigel, with more than 20% Black patients, more than 23% Latino and more than 12% Asian. He said that was due to partnering with hospital trial sites that had access to diverse groups of patients.

“We have got to get a vaccine that works, and it’s not necessarily going to unless we have diversity in trials," said Edward Abrahams, president of the Personalized Medicine Coalition, an education and advocacy group that promotes the understanding of personalized medicine. “We know not all drugs work for all people." 

Diversification strategies

It’s a challenge that drugmakers are trying to address as they move to later-stage trials, when diversity is most key. Early-stage trials are mainly intended to see if it’s safe enough to expand the test pool.

Moderna is focusing on “sites with representative demography" and working with faith-based communities and employers for outreach help to recruit volunteers, a spokeswoman said. Anthony Fauci, head of the NIAID, said Wednesday that it’s pre-enrolled a pool that’s 19% Black and 19% Latino.

London-based AstraZeneca PLC, whose Phase I vaccine trial was 89% White, plans to focus on communities with high minority representation for recruiting test subjects. 

Gilead is partnering with the Satcher Health Leadership Institute at Morehouse School of Medicine to develop a health-equity tool focused on the demographic disparities associated with Covid-19. Similarly, Pfizer is developing a dashboard to help clinical trial investigators pick study sites in communities of color and areas that have seen higher rates of infection.

The lack of minority participants in medical research has been a growing concern for years, as researchers have raised alarms about trials for cancer drugs and genetic research.

Trust issues

There’s evidence this may have real consequences. One 2018 study, for example, sequenced the entire genomes of nearly 1,500 Black and Latino children with asthma and found a genetic variant that may be responsible for why the most popular asthma medication on the market, albuterol, often doesn’t work for them. Knowing whether someone has that variant — or even that medication often doesn’t help people with their backgrounds — could save lives.

In 1993, Congress passed legislation requiring publicly funded medical studies include more women and minorities, and the Food and Drug Administration “encourages the inclusion of diverse populations" in guidelines for developing Covid-19 treatments and vaccines.

“The FDA has a longstanding policy of encouraging inclusion in clinical trials so that participants are representative of the broad population," an agency spokeswoman said.

Persuading minorities to participate isn’t always easy though, especially in the rush for solutions to the pandemic.

“Minorities don’t trust or have access to clinical trials," said Abrahams. “The challenge is two-fold because we are in a rush to develop a vaccine and recruiting minorities takes time."

Beigel said that treatment trials may have better access to diverse subject groups pools than ones for vaccines. The NIH Remdesivir trial, for example, treated hospitalized patients who were less likely to refuse, he said.

The authors of a major study of using hydroxychloroquine to treat Covid-19 also had larger minority representation, with more than 22% Asian participants. The authors attributed that in part to the study being shared widely on WeChat, a Chinese-language social media and messaging platform. Participation fell though to around 5% Black and Latino people.

Tulane University School of Public Health and Tropical Medicine Dean Thomas LaVeist, who also leads the Louisiana Covid-19 Health Equity Task Force, said racial diversity isn’t enough. Age and gender need to be factors, too. The pandemic’s scale means that even if just a small percentage of subjects have an adverse reaction to a drug or vaccine, that could mean millions of people.

“You need to have a study representative of the people actually using the drug," he said. “In this case, that’s everyone."

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