Lilly’s drug is one of a handful of treatments developed to address the underlying pathology of Alzheimer’s, and only one other drug, Lukembi, is commercially available. Approved to treat the early symptoms of Alzheimer’s, the drug cannot halt the progression of the disease, but has been shown to slow cognitive and functional decline.
The debate over these drugs has been particularly fractious because there is no cure for the illness that afflicts more than 6 million Americans. Advocates have been pushing for treatment for the memory-losing disease that imposes a devastating burden on families, but the drugs are plagued by complications such as bleeding in the brain.
Clinical trials have found that Xanla, the brand name for donanemab, slowed cognitive and functional decline by 35% over 18 months in patients with mild cognitive impairment. The drug works by removing sticky plaques in the brain called amyloid beta that are associated with the disease.
Kisunra is the third amyloid-targeting drug to receive FDA approval since 2021, following two treatments, Aduherm and Requenvi, jointly developed by pharmaceutical companies Eisai and Biogen.
Adjuherm’s approval deeply divided the medical community, with critics It wasn’t Pharmaceutical companies stopped selling Aduherm because there wasn’t enough evidence that the drug worked. Lukembi, however, received a warmer reception. Late-stage data showed the treatment slowed cognitive and functional decline by 27% over 18 months, but Aduhelm had conflicting data.
Still, like previous anti-amyloid drugs, donanemab has not been immune to controversy. Three patients who received the drug in clinical trials died from complications from the drug, a condition called ARIA that can cause brain swelling and bleeding. No such deaths occurred in the placebo group. Critics also say donanemab’s benefits, while statistically significant, are modest. Advisory committee members cautioned that risks and benefits may vary depending on a patient’s genetics and how advanced the disease is.
In a statement last month, the FDA suggested it wasn’t overly concerned about the drug’s safety profile, writing that the study results were “broadly consistent” with a class of drugs aimed at reducing or removing amyloid plaque.
Recent Alzheimer’s drugs, while far from a cure, have generated excitement among some researchers and advocates for their potential to alter the course of the disease and essentially buy some patients extra life.
The drug is administered by infusion once a month. A key feature of Lilly’s approach is that patients can stop taking the drug once their amyloid levels have fallen to a certain level, potentially making life easier for them, although it remains unclear how amyloid testing should be carried out.
The approval is unlikely to provide a big boost to Lilly’s profits in the short term. The Indianapolis-based company has a market capitalization of about $820 billion, the eighth-highest among publicly traded U.S. companies and the highest among drugmakers, according to S&P Global Market Intelligence. The company’s stock price has risen mainly on the back of blockbuster diabetes and weight-loss drugs Maunjaro and Zepbound.
Still, Wall Street analysts say the approval is a major win for Lilly and could brighten the outlook for other amyloid-targeting drugs.
This is a developing story and will be updated.
