Regulators urged to speed approval of Alzheimer's drugs after new trial data released

These delays are significant in that they could allow those suffering from Alzheimer’s disease to continue to live independent lives for longer, with many health experts hoping that the new drugs herald a turning point in transforming the debilitating disease into a manageable condition akin to diabetes.

Dr. Susan Kohlhaas, executive director of research and partnerships at Alzheimer’s Research UK, is among those pushing for fast action from regulators to ensure the widest possible benefit from the new drugs, given the critical role speedy intervention plays in how well patients respond to the treatment.

“We now have two potentially life-changing Alzheimer’s treatments on the horizon and we need to see rapid regulatory decisions so people who could benefit from these treatments aren’t left in limbo,” Kohlhaas said in The Guardian. “After 20 years without new Alzheimer’s medicines, people affected by this disease deserve to have answers about new treatments as quickly as possible.”

Though lecanemab has already received approval in the US, UK and Australian regulators have not yet approved either of the medications, which work by reducing the levels of a protein in the brain, cerebral amyloid, that is widely considered a significant market for Alzheimer’s disease.

The donanemab study used a separate Alzheimer’s protein marker known as tau to measure disease progression in participants and place them in groups according to the severity of the disease progression. For those with low and medium levels of tau, disease progression was slowed by 35%, but when high tau participants were added, this number dropped to 22%, highlighting the importance of administering these drugs as soon as possible.

“One of the questions we had was: Does the effect grow over time?” Dr. Daniel Skovronsky, Lilly’s chief of research, said in an interview with CNN. “That’s important because Alzheimer’s disease is a chronic disease that can last a decade or more.”

According to Skovronsky, at every trial stage, the drug's cognitive benefits were evident compared to the placebo group, and the difference between the two groups widened as time went on.

Lilly also set up the trial in such a way that if a participant cleared enough cerebral amyloid, they could be switched over to placebo and continue to be monitored. Roughly half of the participants had eventually switched over to placebo by the one-year mark, Skovronsky said, and that those participants continued to see benefits even though they had stopped taking the drug.

“We were delighted to see that,” Skovronsky said. “Once you get rid of the [cerebral amyloid] plaques, you’ve fundamentally changed the trajectory of the disease in a positive way. You don’t need to continue to take therapy to get those benefits.”