What does genetic research contribute to medicine?

Researchers studying disease genetics often say that their work may lead to potential treatments. Companies have invested heavily in human genetics programs to help identify new drug targets. And efforts to identify a new drug and bring it to market after observing a link between gene and disease can take decades. “Geneticists work really hard,” says Vincent Mooser, a geneticist at McGill University. “So has it been useful or not?”

In a new study, Mooser and colleagues analyzed the literature in search of drugs that would not have existed without insights from human genetics (Nature 2023, DOI: 10.1038/s41586-023-06388-8). They assessed 7,000 combinations of drug, target, and disease indications that had been approved by the US Food and Drug Administration by September 2022 and identified 40 such therapies, most of them for rare diseases.

Among these examples, Mooser and colleagues “have a lot of confidence that it actually was genetics that led the drug discovery program,” says David Ochoa, coordinator of the Open Targets Platform, a public-private partnership focused on identifying and prioritizing drug targets. But he says he was surprised by the relatively small number.

In a prior study curated manually, Ochoa and colleagues found that two-thirds of the 50 drugs approved by the FDA in 2021 were supported by genetic data (Nat. Rev. Drug Discovery 2022, DOI: 10.1038/d41573-022-00120-3). And an influential 2015 study showed that when genetic evidence links a gene to a disease, a drug candidate targeting that gene is twice as likely to receive FDA approval (Nat. Genet. 2015, DOI: 10.1038/ng.3314). But these studies did not establish that corporate decision-makers took existing genetic evidence into account. “The real figure on the true impact of human genetics probably lies somewhere between the two,” Ochoa says.

“What we describe is the tip of the iceberg,” Mooser says, noting that many drug development programs have been informed by genetic evidence without solely relying on it. While genetics can contribute to drug discovery, he says, “We need to . . . manage expectations. It’s great to find a new genetic association. But don’t forget, it takes 20 years to get a drug.”