Alzheimer’s treatment slowed cognitive decline in closely watched trial


ABiogen and Eisai’s treatment of Alzheimer’s disease slowed the rate of cognitive decline by 27% in a clinical trial, the companies said Tuesday, meeting the goals of a close study and filing the drug’s application for approval. January strengthened.

The positive result is good news for the millions of people living with Alzheimer’s disease and a big win for Eisai and Biogen, giving the companies a potentially blockbuster product in intravenous medicine called lecanemab. For Biogen, which presided over the disastrous rollout of the Alzheimer’s treatment Aduhelm, the potential approval of lecanemab offers a rare second chance in a multibillion-dollar market.

The lecanemab study is a “key milestone for Eisai in fulfilling our mission to meet the expectations of the Alzheimer’s community,” Eisai CEO Haruo Naito said in a statement.


In the study, which involved approximately 1,800 patients with early-stage Alzheimer’s disease, lecanemab outperformed placebo. The treatment also met the secondary goals of reducing toxic plaques in the brain and slowing patients’ decline on three other measures of memory and function.

About 21% of patients treated with lecanemab experienced brain swelling or cerebral hemorrhage visible on PET scans, a side effect associated with medicines of this type. Less than 3% of those patients had symptomatic cases, the companies said.


The study, called CLARITY-AD, was the largest yet conducted to test the long-discussed theory that clearing toxic brain plaques called amyloid could slow the rate of Alzheimer’s disease by slowing the rate of memory loss. or delay the onset of dementia.

Lecanemab is the first treatment of its kind to confirm the so-called amyloid hypothesis in a large Phase 3 clinical trial after two decades of consistent failure and shady results from similar, experimental drugs.

“This is a statistically robust and positive study, but the effect of the treatment is small,” said Lon Schneider, a physician and Alzheimer’s expert at the Keck School of Medicine at the University of Southern California. Schneider cautioned that experts will need to look at the lecanemab data much more closely when presented in more detail, but based on the results described in Eisai’s press release, he believes lecanemab will likely receive approval from the Food and Drug Administration. Schneider was not involved in the investigation.

In a telephone briefing to reporters on Tuesday night, Ivan Cheung, president of Eisai’s US operations and global head of the Alzheimer’s unit, said the positive treatment effect of lecanemab emerged six months into the study and was greatest at the latest time point, 18 months. Cheung called the benefit to patients “very clinically meaningful” but also acknowledged that opinions will differ.

The FDA is already considering lecanemab for conditional approval, promising to make a decision by Jan. 6 based on preliminary evidence from a smaller study showing the drug’s effect on amyloid in patients’ brains. Eisai now plans to add the more definitive results of the CLARITY-AD study to the filing, with the goal of getting full approval by the summer and convincing Medicare to roll back a restrictive reimbursement policy instituted in the aftermath of Aduhelm.

CLARITY-AD may be enough to convince the FDA, but the future of lecanemab depends on whether doctors, payers and patients find the supporting data convincing. The study used a metric called the Clinical Dementia Rating sum of boxes, or CDR-SB, which measures six cognitive domains, including memory, problem solving and personal care, yielding scores ranging from 0 to 18, with higher numbers indicating more severe severity. dementia. .

In the 18-month study, patients who received lecanemab did 0.45 points better on the test than those who received placebo, a result that reached the threshold of statistical significance, meaning it’s unlikely to be the result of random chance.

In a similar clinical study, Aduhelm slowed the decline by 22% and outperformed placebo by 0.39 points by the same measure. A second, identical investigation failed.

Lecanemab was administered as an intravenous infusion twice monthly. About 25% of the 1,800 participants in the CLARITY-AD study were Hispanic and African Americans, making it one of the more diverse populations ever to participate in an Alzheimer’s disease clinical trial.

The Alzheimer’s Association, which has actively lobbied the FDA to approve new treatments, released a statement Tuesday evening. “These are the most encouraging results in clinical trials to date treating the underlying causes of Alzheimer’s disease,” the group said.

For lecanemab, statistical significance does not necessarily lead to a life-altering drug. Alzheimer’s researchers have debated for years what small changes in CDR-SB scores mean for patients with the disease. A fractional improvement on an 18-point scale may not be detectable in real life. On the other hand, the metric is not an interval scale, which means that the numerical differences are not proportional to each other. Going from a 1 to a 1.5 on the CDR-SB could mean you can no longer drive alone, while probably making little difference to a patient who already has dementia.

For Michael Greicius, a neurologist at Stanford University who studies and treats Alzheimer’s disease, the rate of brain swelling in the lecanemab study could be confusing. Once patients present with the common side effect called ARIA, everyone involved in the study can be pretty sure they’re getting the drug and not the placebo, exposing the study to bias. A real test of lecanemab’s benefits would just be whether it helped the patients who didn’t test positive for ARIA, Greicius said.

“I think this is at the point of what’s considered minimally clinically significant, and it could be below that,” said Greicius, who was not involved in the study. “We need to see more data there.”

Experts said a final ruling on lecanemab’s value will require more detailed results from CLARITY-AD, which Eisai has promised to present at a medical conference in November.

Wall Street had only moderate expectations for CLARITY-AD, with analysts estimating a low probability of success and declaring that even a marginal benefit would count as positive for Biogen and Eisai. Biogen’s stock price has fallen nearly 50% since Aduhelm’s approval in 2021 and Eisai has lost about 60% of its value.

“Today’s announcement gives patients and their families hope that lecanemab, if approved, could potentially slow the progression of Alzheimer’s disease and have a clinically meaningful impact on cognition and function,” said Michel Vounatsos, CEO of Biogen, in a statement. declaration.

Biogen’s stock price rose 44% to $285 in Wednesday’s pre-market trading, adding $13 billion to the company’s market value. Eisai’s US-listed American Depositary Receipts were not yet open to trading.

In a published research paper, Brian Skorney, a biotech analyst at RW Baird and a long-time critic of Biogen and its Alzheimer’s drug programs, described the results of the lecanemab study as “practically a best-case scenario that should not only lead to approval and reimbursement but could make it challenging for the competition (assuming they are successful) to match Skorney raised his Biogen rating from “neutral” to “outperform.”

The results kick off what will be a transformative nine months for Alzheimer’s research. By the end of this year, Roche will have data from a two-year study of gantenerumab, another antibody that reduces brain plaques. And in the first half of 2023, Eli Lilly expects to have results from a phase 3 trial of donanemab, a similar treatment that met its goals in a small study last year.

The Valley Voice
The Valley Voice
Christopher Brito is a social media producer and trending writer for The Valley Voice, with a focus on sports and stories related to race and culture.


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