Eli Lilly has stopped development of semagacestat, a gamma secretase inhibitor for the treatment of Alzheimer’s disease, as it has not shown favourable results in long-term Phase III studies.

The two Phase III trials involved 2,600 patients with mild-to-moderate Alzheimer’s disease, who received either semagacestat or a placebo.

The drug did not slow down the progression of the disease, and patients taking it showed worsening cognition and ability to perform daily activities.

Semagacestat was also associated with increased risk of skin cancer.

Lilly is instructing the clinical trial investigators to contact and inform the study patients to immediately stop taking semagacestat.

Lilly has announced that the decision to halt the drug development does not affect the ongoing trials of solanezumab, its other potential Alzheimer’s treatment.