The FDA rejected Eli Lilly's request to expedite the approval process for experimental Alzheimer's drug donanemab, but the drug's Phase 3 trial is carrying forward as planned.
According to drugmaker Eli Lilly, the FDA has rejected the company’s application for the FDA’s “Accelerated Approval” designation for experimental Alzheimer’s drug donanemab. The drug is currently in Phase 2 trials.
Like donanemab’s predecessors — aducanumab (on the market as Aduhelm) and lecanemab (on the market as Leqembi), both from drugmakers Biogen and Eisai — Eli Lilly’s donanemab is a monoclonal antibody designed for people in the early stages of Alzheimer’s. Most Alzheimer’s drugs on the market are designed to treat the disease’s symptoms. This new class of monoclonal antibodies, however, are designed to attack the disease’s suspected root cause — beta-amyloid protein build-ups in the brain — and slow or even stop disease progression.
Donanemab received the FDA’s breakthrough therapy designation in June of 2021 — bringing it into a program meant to smooth the way for development and review of candidate drugs for serious or life-threatening illnesses.
A few months earlier, in March 2021, Eli Lilly had shared data from its Phase 2 TRAILBLAZER-ALZ clinical trial — a relatively small, randomized, placebo-controlled, double-blind, multi-center study measuring the safety, tolerability and efficacy of donanemab in patients with early symptomatic Alzheimer’s. According to this 2021 data, donanemab appeared to slow cognitive decline while “rapidly” clearing amyloid plaques, according to the drugmakers. The next win for the drug would have been this accelerated approval pathway.
Drugs that score FDA Accelerated Approval still undergo the rigorous evaluation and are held to the same standards as those outside the program, but it bumps them closer to the front of the line and cuts down the wait time before a decision.
Eli Lilly in August of 2022 submitted its Phase 2 data to the FDA. However, the agency wasn’t impressed enough by the drugmaker’s early donanemab trial data to warrant this expedited evaluation process. The regulators sent the drugmaker a letter stating that they would not extend accelerated approval because not enough of the drug’s 100 Phase 2 trial participants had been receiving the drug for a full 12 months. They want to see more data from participants who’ve been in the trial for longer. In the meantime, Eli Lilly reports that the next phase of donanemab’s clinical trials is still on track for mid-2023.
UsAgainstAlzheimer’s chief operating officer Russ Paulsen said that while the organization is disappointed this treatment won’t be made available sooner, the reasoning behind the FDA’s rejection of accelerated approval is encouraging:
“Donanemab worked too well to meet the criteria required by the FDA, 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,” Paulsen said. “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.”
If Lilly’s Phase 3 trial data shows the drug is safe and effective, the company will apply for donanemab’s FDA approval “shortly thereafter.” Trials are expected to be completed by 2027.