Shares in Eli Lilly fell more than 15 percent Wednesday after the company announced that the experimental drug solanezumab failed to meet the primary endpoint of a Phase III study in people with mild dementia due to Alzheimer's disease. The company said that as a result it will not pursue regulatory submissions for the monoclonal antibody for the treatment of mild dementia due to Alzheimer's disease.
Top-line results from the EXPEDITION3 study showed that patients treated with solanezumab did not experience a significant slowing in cognitive decline compared to patients treated with placebo, as measured by the ADAS-Cog14. Eli Lilly added that while the findings, including many secondary goals, "directionally favoured" solanezumab, the "magnitudes of treatment differences were small."
The study, which enrolled more than 2100 patients diagnosed with mild dementia due to Alzheimer's disease, was initiated  in 2013 after other late-stage study data suggested a benefit of early treatment with solanezumab among people with mild Alzheimer's disease. Earlier this year, Eli Lilly altered the primary endpoint of the study to include a single assessment of cognition, rather than co-primary endpoints of cognition and function, to reflect "emerging scientific evidence" that cognitive decline precedes and predicts functional decline in Alzheimer's disease, particularly in earlier stages of the condition.
"The results...were not what we had hoped for," remarked CEO John C. Lechleiter, adding it could take "weeks or months" to figure out what went wrong with solanezumab. The executive said the company "will evaluate the impact of these results on the development plans for solanezumab and our other Alzheimer's pipeline assets," which he noted include "an oral drug we're testing now in Phase III [and]...five other therapeutic agents in early stages of development."
According to Eli Lilly, the failure of the trial is expected to result in a fourth-quarter charge of approximately $150 million. Some analysts had predicted that if approved, solanezumab could have generated annual sales of more than $5 billion.
David A. Ricks, the company's incoming CEO, remarked that Eli Lilly had been planning for the failure of solanezumab, adding "we knew it was a high-risk, high-reward programme." Ricks said "Lilly has strong growth prospects without solanezumab," and continues "to expect to grow average annual revenue by at least 5 percent between 2015 and 2020." The executive commented "we have a lot going on beyond Alzheimer's, launches in diabetes and oncology and immunology."
Meanwhile, shares in Biogen, which is developing a similar drug targeting beta amyloid, fell as much as nearly 9 percent Wednesday. The company began enrolling  patients last year in a Phase III clinical programme designed to evaluate the efficacy and safety of aducanumab, also known as BIIB037, in slowing cognitive impairment and the progression of disability in early Alzheimer's disease.