U.S. antitrust regulators joined their European counterparts this month by ruling that DNA sequencing giant Illumina must divest itself of Grail, the cancer diagnostics firm that Illumina spun out in 2016 before reacquiring it 5 years later in a $7.1 billion deal completed without regulatory approval.

Many cancer researchers and policy advocates welcomed the move, agreeing with the Federal Trade Commission (FTC) that Illumina, as the main supplier of next-generation sequencing technology for liquid biopsies, had a financial incentive to prioritize Grail’s access to its platforms. They also worried that the merger, if left intact, might squeeze out rival developers of multi-cancer early detection (MCED) diagnostics.

“The recent decision does subvert the risk of any potential favoritism and will allow multi-cancer detection tests to compete based on their performance data,” says Jeff Allen, PhD, president and CEO of Friends of Cancer Research in Washington, DC.

Illumina will appeal the decision—and for good reason, says Aurelien Portuese, PhD, of the Information Technology and Innovation Foundation in Washington, DC. An expert in antitrust and competition policy, Portuese disputes the FTC’s claims that the breakup is necessary to maintain a level playing field. “It’s a very flawed analysis,” he says.

Illumina pledged not to raise prices on its sequencing products or to deny access to any test developers for at least another 10 years. Regulators could have made that promise legally binding, but instead chose to “protect speculative claims,” Portuese says, based on a “creative theory of harm.”

That harm might not be apparent today, but Christoph Lengauer, PhD, MBA, cofounder and former chief innovation officer of Thrive Earlier Detection, a MCED developer now owned by Exact Sciences, worries about a future when Illumina invariably updates its machines in ways that might give Grail an edge.

“We currently have no alternatives to Illumina, and that’s what makes things complicated,” he says.

“Our technologies are inherently dependent on the chemistry that those machines have built-in,” he continues. The last time Illumina changed its platform, elevating its newer two-color NovaSeq system and phasing out older four-color HiSeq instruments, it took Lengauer and his colleagues roughly 7 months to adapt their blood assay. “It’s not just a little change,” he says. “Everything has to be redone because they switched the chemistry.”

Would Illumina, if it owned Grail, advance any technology that set back its own product development in similar ways? Lengauer, now cofounder and CSO of the venture capital firm Curie Bio, doubts it; he voiced that skepticism in testimony given as part of the FTC’s administrative proceedings.

Grail’s Galleri blood assay, which analyzes methylation patterns in cell-free DNA to detect more than 50 cancers, is sold by prescription for $949 as a laboratory-developed test. It is not covered by most insurance, however, and so is not in widespread use.

In a year-long study of about 6,600 older adults, Grail scientists found that the test helped detect many more early-stage cancers than standard screening protocols alone (Cancer Discov 2022;12:2487–8). Grail is running larger trials—including PATHFINDER 2 in North America and the NHS-Galleri trial in the UK—to support approval from the FDA and other regulatory authorities.

In theory, disentangling Grail from Illumina could create legal and logistical challenges that slow recruitment or data collection for these studies. But Aadel Chaudhuri, MD, PhD, of Washington University School of Medicine in St. Louis, MO, doubts the impacts will be substantial. “Even if it were to turn into an ugly sort of legal battle, I don’t see this necessarily slowing the accruals of these ongoing studies that are already being led by highly capable clinicians who are very good at running trials,” he says.

An independent Grail should also maintain its dominant position in the MCED field because, as Chaudhuri points out, “they are further ahead than the other companies by virtue of having these large prospective studies already off the ground.” –Elie Dolgin