The Food and Drug Administration has agreed to an expedited review of Eli Lilly's experimental Alzheimer's disease medicine donanemab, the pharmaceutical company said Thursday.
The agency's acceptance of Lilly's application starts a six month clock, setting up a potential decision from the regulator by early February. Lilly had not previously disclosed completion of the application, which it began submitting last fall but slowed after Medicare finalized a restrictive coverage policy for Alzheimer's drugs like Lilly's.
Donanemab is one of several drugs in late-stage clinical testing that are aimed at a protein called amyloid beta, which accumulates in sticky plaques in the brain. Targeting this protein has been the dominant approach toward treating Alzheimer's for decades, but has yielded a long list of failed drugs and unsuccessful studies.
Last summer, Biogen won a controversial FDA approval for its amyloid-targeting drug Aduhelm, despite contradictory clinical trial evidence it worked. Rather than rule directly on the drug's impact on cognitive decline in patients with Alzheimer's, the FDA granted an accelerated approval based on its ability to reduce amyloid levels.
Lilly is applying for a similar accelerated approval. Its application is supported by results from a mid-stage study that showed donanemab substantially cleared out amyloid plaques in the brains of trial participants. Data also suggested a cognitive and functional benefit to treatment, which Lilly is seeking to confirm with a larger Phase 3 study that's now ongoing.
While approval would be a major milestone for Lilly, the company doesn't expect significant use of the drug right away due to a coverage policy instituted by the Centers for Medicare and Medicaid Services. Unconvinced by the evidence for Aduhelm, CMS restricted Medicare coverage of the drug, as well other amyloid-target medicines like it, to patients in certain types of clinical trials.
"In the near term, of course, we have to acknowledge that patient access will be very limited under the current CMS [policy] with accelerated approval," said Anne White, head of Lilly's neuroscience division, on an earnings call Thursday.
"What we'll do in the near term, following a potential approval ... is use that time to build out the diagnostic ecosystem, to help physicians with the referral process and infusion systems," she added.
Should Lilly's ongoing Phase 3 study succeed, Lilly would be in position to ask the FDA for full approval of donanemab, potentially allowing more favorable coverage under the CMS policy.
"We remain optimistic that with traditional FDA approval, CMS would not continue to limit coverage for on-label treatments," White said.
In between now and when Lilly's trial is set to read out early next year, results are expected to become available for two other amyloid-targeting drugs: Eisai and Biogen's lecanemab, and Roche's gantenerumab. As the drugs belong to the same family of treatments, those results could influence how analysts and investors view the likelihood of a positive Phase 3 outcome for donanemab.
On Thursday's call, White sought to set expectations. "There's a chance that we'll see mixed results in some of these readouts due to the differences in the medicines and their trial designs," White said. "We won't be discouraged if others miss their primary endpoints."