Eli Lilly and Company has presented the detailed results for the phase III, double-blind, placebo-controlled EXPEDITION studies in patients with mild-to-moderate Alzheimer's disease at the annual meeting of the American Neurological Association (ANA). The presentation of results from independent analyses of the EXPEDITION study data was conducted by the Alzheimer's Disease Cooperative Study (ADCS), an academic research consortium.
The data was conceived by Rachelle Doody, MD, Ph.D., professor of Neurology and the Effie Marie Cain Chair in Alzheimer's Disease Research, Baylor College of Medicine. Dr Doody is a member of the steering committee for the ADCS.
Lilly provided the raw data to the ADCS. The ADCS statisticians then performed independent analyses of these data.
"Alzheimer's disease research has been extremely challenging," said Dr. Doody. "The data results from the solanezumab phase III trials were encouraging to the ADCS team. These results represent an important step for the medical, academic, and scientific communities in understanding brain amyloid as a target of AD therapies."
Lilly's relationship with the ADCS is longstanding and the decision to have them conduct independent analyses of the phase III solanezumab data was made prior to seeing the top-line results from either of the EXPEDITION studies.
The EXPEDITION1 study was designed with co-primary cognitive and functional endpoints (the Alzheimer's Disease Assessment Scale- Cognitive subscale [ADAS-Cog11] and the Alzheimer's Disease Cooperative Study-Activities of Daily Living [ADCS-ADL], respectively) in patients with mild-to-moderate Alzeimer's disease.
Lilly's pre-specified secondary analyses showed that results in patients with mild Alzheimer's disease taking solanezumab demonstrated a slowing of cognitive decline compared with placebo (p=.008), as measured by the ADAS- Cog11. This finding represented a 42 per cent reduction in decline at the endpoint of the 18-month study. The difference in functional decline (ADCS-ADL) was not statistically significant.
Based on the results of EXPEDITION1, Lilly modified the statistical analysis plan (SAP) for EXPEDITION2, prior to database lock, to specify a single primary endpoint of cognition in patients with mild Alzheimer's disease as measured by the ADAS-Cog14, a 14-item scale, which includes three additional items considered relevant for patients with mild Alzheimer's disease. At the conclusion of EXPEDITION2, there was a 20 percent reduction in cognitive decline in patients with mild Alzheimer's disease taking solanezumab; however, the treatment difference was not statistically significant (p=.120). In the pre-specified secondary endpoint of ADCS-ADL, there was a 19 per cent reduction in functional decline in patients with mild Alzheimer's disease treated with solanezumab, as compared with placebo; this difference was not statistically significant (p=.076).
A pre-specified secondary analysis of pooled data in patients with mild Alzheimer's disease showed a slowing of cognitive decline (p=.001) compared with placebo, as measured by the ADAS-Cog14; this finding represented a 34 per cent reduction in decline. In addition, the secondary analysis of the pooled data in patients with mild Alzheimer's disease showed a 17 per cent reduction of functional decline as measured by the ADCS-ADL; however, the treatment difference was not statistically significant compared with placebo (p=.057).
A number of different biomarkers were assessed in the EXPEDITION studies. Some, but not all, of these biomarkers showed an effect of solanezumab. These additional data will be presented by the ADCS at the Clinical Trials on Alzheimer's Disease (CTAD) meeting in Monte Carlo, Monaco, on October 29, 2012, or at subsequent medical meetings and in appropriate scientific venues.
In the EXPEDITION studies, the only adverse event with an incidence of at least 1 percent that occurred statistically significantly more in the solanezumab group than in the placebo group was angina (1.1 per cent versus 0.2 per cent). The incidence of vasogenic edema (ARIA-E) was approximately 1 per cent, occurring in 11 patients treated with solanezumab and five patients on placebo, which was not statistically significant.
"This is a complex disease that touches millions of people worldwide," said David Ricks, senior vice president and president, Lilly Bio-Medicines. "Alzheimer's disease causes significant burden on patients, caregivers and our society. While the path forward has not been determined, we believe these data in patients with mild disease may provide a step toward a potential treatment option."
The ADAS-Cog is a standard tool used in pivotal clinical trials to detect therapeutic efficacy in cognition. It consists of subtests related to memory, praxis, and language. Higher scores on the ADAS-Cog indicate more cognitive impairment. The ADCS-ADL measures activities of daily living, such as reading books or magazines, pastime activities, or household chores. Higher scores on the ADCS-ADL indicate less functional impairment.
The EXPEDITION trials consisted of two phase III, double-blind, placebo-controlled solanezumab trials in patients with mild-to-moderate Alzheimer's disease in 16 countries around the world. In both of the EXPEDITION study protocols, mild Alzheimer's disease was defined as a baseline Mini-Mental Status Examination (MMSE) score of 20 to 26 and moderate Alzheimer's disease was defined as a baseline MMSE score of 16 to 19.
The designs of EXPEDITION1 and EXPEDITION2 were the same. Patients aged 55-94 years were eligible to enroll in these studies; EXPEDITION1 enrolled 1,012 patients and EXPEDITION2 enrolled 1,040 patients. Patients received either 400mg of solanezumab infused intravenously (IV) or placebo every four weeks for approximately 18 months. Both EXPEDITION trials allowed patients to remain on stable standard of care (defined as their existing treatment regimen) during these studies. More than 85 percent of the patients in these trials were taking an acetycholinesterase inhibitor and / or memantine.
Alzheimer's disease, the most common form of dementia, causes progressive decline in memory and other aspects of cognition. Researchers do not know exactly what causes Alzheimer's disease and there are currently no approved treatments shown to slow the progression of this devastating disease, only treatment options that reduce certain symptoms of the disease.
Lilly, a leading innovation-driven corporation, is developing a growing portfolio of pharmaceutical products by applying the latest research from its own worldwide laboratories and from collaborations with eminent scientific organizations.