After a week of good news for Alzheimer’s patients, Eli Lilly dropped the bombshell that it had stopped development of one of its experimental Alzheimer’s disease treatments due to the fact that patients in two late-stage clinical trials actually experienced more memory loss than those on a placebo.
The treatment in question, semagacestat, was involved in two Phase III trials encompassing 2,600 patients with low to medium levels of Alzheimer’s disease progression. In both cases, the disease advanced and memory loss increased, but patients taking semagacestat saw a “statistically significant greater degree” of cognition problems than the placebo group. Additionally, patients on the treatment had an increased risk of skin cancer—not a good sign at all.
Semagacestat is an oral treatment that was intended to halt creation of an enzyme called amyloid beta plaque—believed to be what leads to memory loss and Alzheimer’s disease.
“This is disappointing news for the millions of Alzheimer's patients and their families worldwide who anxiously await a successful treatment for this devastating illness,” stated Jan M. Lundberg, president, Lilly Research Laboratories. “This is a setback, but Lilly’s commitment to beating Alzheimer’s will not waver.”
Lilly asked anyone taking the medicine to discontinue treatment as soon as possible and go see a doctor. The drug firm will continue to track patients on the treatment to monitor for any additional safety problems.
The company is now banking on solanezumab, also in Phase III trials, as a treatment for Alzheimer’s disease. According to Lilly, both compounds were designed to defeat amyloid beta plaque, but solanezumab functions in a different manner, and therefore shouldn’t have the same problems semagacestat had.
Alzheimer’s is an extremely difficult disease to diagnose because it can’t be confirmed without a post-mortem autopsy. Physicians basically gauge the likelihood that a patient has the disease by process of elimination, making treatment and drug development problematic.