Editors' (re)View: AdComm nod for Lilly Alzheimer's drug; SCOTUS mifepristone decision
Cautious optimism: Eli Lilly Alzheimer's drug gains AdComm nod
This week, we reported that the FDA’s Peripheral and Central Nervous System Drugs Advisory Committee (PCNS) unanimously voted in favor of Eli Lilly's experimental Alzheimer's drug, donanemab, citing that its benefits outweighed the risks for early-stage patients.
Although the agency’s decision is not dependent on the meeting’s outcome, the positive vote indicated a clear path for the FDA's final decision.
The study featured a limited-duration dosing regimen, allowing treatment completion based on amyloid plaque assessment and included participants based on tau protein levels. The trial demonstrated a 29% reduction in memory decline among Alzheimer's patients. Concerns were raised over amyloid-related imaging abnormalities (ARIA), which include brain swelling and microhemorrhages, significant safety considerations observed in patients taking other Alzheimer's drugs as well.
Despite safety concerns, including brain swelling and bleeding, the panel highlighted the trial's flexible treatment approach, which allows discontinuation once amyloid plaques clear. Donanemab targets and removes beta-amyloid plaques, toxic proteins that accumulate in the brains of people with Alzheimer's. By reducing beta-amyloid levels, donanemab aims to slow the progression of memory and cognitive decline in early-stage Alzheimer's patients.
But Alzheimer’s drugs are notorious for their fickle fates.
A few months ago, Biogen announced it would discontinue its Aduhelm program to "reprioritize its resources in Alzheimer’s disease." The company halted development and commercialization of the controversial drug and terminated the post-marketing confirmatory ENVISION study.
Biogen said it would instead focus on advancing Leqembi, which received full FDA approval in July 2023, and accelerate development of other treatments, including its ASO targeting tau (BIIB080) and an oral small molecule inhibitor of tau aggregation (BIIB113).
For Aduhelm, a discontinuation didn’t necessarily come as a surprise for those who kept a close eye on its rocky approval journey, unfavorable national coverage policies in the U.S., and Biogen calling it quits on an observational trial.
The questions remains: why is it so difficult to produce a meaningful treatment for the neurodegenerative disease?
In short, the disease's exact causes are still not fully understood. Amyloid plaques and tau proteins are central to current research; suggesting that Alzheimer's is caused by the buildup of amyloid plaques and tau protein tangles in the brain, which disrupt cell function and lead to cognitive decline. However, despite targeting these plaques and tangles, many treatments have failed to show significant clinical benefits, highlighting the difficulty of translating these hypotheses into effective therapies.
The complexity of Alzheimer's makes finding a one-size-fits-all solution elusive. While there is hope on the horizon, an effective treatment may be further away than any of us wishes it were. — Andrea Corona
Did SCOTUS punt on the mifepristone decision?
Yesterday, SCOTUS issued a rare unanimous opinion regarding FDA’s relaxed rules for prescribing and dispensing mifepristone.
In 2016, in an effort to make the drug more accessible, the FDA changed the drug's REMS program. These changes increased the maximum gestational age to 70 days, eliminated the in-person dispensing requirement, allowed non-doctors to prescribe mifepristone, and eliminated reporting of non-fatal adverse events.
In a highly anticipated decision, the nine justices threw out the lawsuit on procedural grounds — ruling that because the Alliance for Hippocratic Medicine (a group of anti-abortion doctors formed in 2022) failed to demonstrate that they were injured by the FDA’s actions, the case didn’t belong in federal court.
While the court did acknowledge that allowing doctors to challenge FDA drug approvals would open pandora’s box (“That path would seemingly not end until virtually every citizen had standing to challenge virtually every government action that they do not like.”) the fact that suit was tossed on procedural grounds means that SCOTUS didn’t actually address the issue of whether the FDA acted lawfully when it relaxed the rules for mifepristone.
This rationale leaves the door open for other groups to attempt to establish standing to challenge mifepristone or other politically contentious FDA decisions. So while it is a win for abortion access, it doesn't mean the fight is over for mifepristone or FDA authority. With more cases working their way through the courts, abortion bans in 14 states and the election just around the corner, this definitely isn't the end of the story. —Karen Langhauser
