FDA Rejects Fast-Track Approval of Eli Lilly's New Alzheimer's Drug

Regulators want more evidence that the pricey drug works.

The Food and Drug Administration has rejected fast-track approval for Eli Lilly and Co.'s Alzheimer's drug donanemab, telling the company that it must produce more research showing the pricey drug's efficacy is needed before they'll green light it.

In a media release Thursday night announcing the decision, Indianapolis-based Lilly says the FDA "specifically requested that Lilly provide data from at least 100 patients who received a minimum of 12 months of continued treatment on donanemab."

"While the trial included more than 100 patients treated with donanemab, due to the speed of plaque reduction, many patients were able to stop dosing as early as 6 months of treatment, resulting in fewer than 100 patients receiving 12 months of donanemab," Lilly says. "The FDA indicated that the data to meet the exposure expectation would likely need to include the unblinded controlled safety data from TRAILBLAZER-ALZ 2 upon completion." 

No other shortcomings in the application were noted by the FDA.

Lilly says an expanded Phase 3 clinical trial for the drug is underway and will be completed this year. The drug maker says it is confident that those results will prove the efficacy of the monoclonal antibody treatment and they plan to resubmit an application for fast-track status.

"We look forward to our upcoming confirmatory TRAILBLAZER-ALZ 2 Phase 3 results and subsequent FDA submission, which we've always seen as the most impactful next steps for patients," Lilly Neuroscience President Anne White says.

"We anticipate this study will confirm the benefit and safety profile we observed in the TRAILBLAZER-ALZ Phase 2 study and believe that patients and physicians will be well served by having the full Phase 3 data available alongside our Phase 2 data when they need to make treatment decisions," White says.

"We are committed to working with the FDA to ensure the fastest possible path to bring this potential medicine to patients in need."

The FDA has already granted limited fast-track approval for two similar Alzheimer's treatments; Biogen and Eisai's aducanumab, and  BioGen's lecanemab (Leqembi). The three drugs target beta amyloid protein accumulations in the brains of Alzheimer's patients.

An independent analysis estimates that donanemab would be cost-effective at a price of about $20,000 a year, but with the caveat that the true cost-effectiveness will not be known until at least the results of the Phase 3 trials are completed. Leqembi cost-effectiveness threshold is about $26,500 a year, and aducanumab's is about $23,000 a year.

UsAgainstAlzheimer's COO Russ Paulsen offered a mixed reaction to the FDA's action.

"While we are disappointed this treatment won't be made available to patients sooner, the reason why is encouraging: donanemab worked too well to meet the criteria required by the FDA," Paulsen says.

"The FDA requires a minimum of 100 patients to be on the drug for at least twelve months but, due to donanemab's quick action in some patients, many were able to stop treatment in as little as six months. We are very encouraged by that and look forward to learning even more about donanemab's effectiveness when Lilly releases its Phase 3 trial data later this year in advance of its application for traditional FDA approval."