Eisai to drop up to $15M on C2N Diagnostics to boost the reach of Alzheimer's disease blood tests

After netting a historic FDA drug nod in Alzheimer’s disease last year—and seeing a relatively slow commercial rollout in the time since—Eisai is now re-upping its investment in Alzheimer’s blood test developer C2N Diagnostics.

The Tokyo-based drugmaker has pledged up to $15 million for the former Fierce 15 winner and its Precivity blood tests, which are designed to detect the tau and beta amyloid proteins that have made their way into the bloodstream from plaques in the brain. C2N has shown that its approach can perform on par with pricey brain imaging scans and invasive spinal tap biopsy procedures.

“Given the expense and capacity limitations of PET and CSF tests, Eisai is working to support the dementia ecosystem’s growth,” Eisai’s global Alzheimer’s disease officer, Keisuke Naito, said in a statement. “The availability of more affordable and minimally invasive diagnostic tools helps support broad access for the management of Alzheimer’s disease.”

Separately, Eisai has been working with organizations to develop digital tools for diagnosing dementias, including an artificial intelligence collaboration focused on the U.K. with help from Gates Ventures, the University of Edinburgh, Health Data Research UK and LifeArc.

Blood testing, however, has the opportunity to make diagnosing Alzheimer’s more efficient and affordable, the company said, especially among underserved communities where amyloid PET and cerebrospinal fluid exams may not be available. 

Eisai previously joined C2N on a project to assemble real-world evidence that supports the use of blood tests in people with cognitive impairment who are not participating in a clinical trial. In addition, C2N’s Precivity tests were employed in clinical trials for Leqembi (lecanemab), the anti-amyloid antibody developed by Eisai and its partner Biogen.

The two pharmas received a full FDA green light for Leqembi in July 2023, about six months after gaining an accelerated approval. The drug marked the first treatment for slowing Alzheimer’s progression and cognitive decline to make it through the agency’s traditional pathway. 

But in the months that have followed, Leqembi has not met the companies’ sales goals. In early February, Eisai disclosed in its quarterly earnings report that only 2,000 people in the U.S. had received the treatment by late January—far short of the 10,000-patient goal it had set for the end of its fiscal year. Demand, however, remains high, as Eisai counted about 8,000 on a waitlist at the time.

At C2N, the company said the investment will help scale up access to its Precivity test aimed at earlier diagnoses.

“With this financing, we’re building on our history of attracting the highest-quality investors committed to changing the trajectory of Alzheimer’s disease through early detection and treatment and, ultimately, prevention,” said C2N CEO Joel Braunstein, M.D. 

“The availability of blood biomarkers that are closely correlated with gold standard measures, such as positron emission tomography (PET) scans, will improve accessibility for patients to obtain safe and effective drug treatments as more become available,” Braunstein said.