Alector Therapeutics' Phase 2 INVOKE-2 trial of AL002, an experimental antibody targeting microglia activation for Alzheimer's disease, has failed to meet its primary endpoint. The trial, which involved 381 patients with early Alzheimer's, did not show a significant slowing of disease progression compared to placebo, as measured by the Clinical Dementia Rating Sum of Boxes (CDR-SB).
The company reported that the study also failed to demonstrate treatment effects favoring AL002 on secondary clinical and functional endpoints. Furthermore, there were no significant effects on Alzheimer's fluid biomarkers, and amyloid PET imaging showed no treatment-related reduction of brain amyloid levels.
Trial Details and Discontinuation
The INVOKE-2 trial (NCT04592874) aimed to assess the efficacy and safety of AL002 in slowing the progression of early Alzheimer's disease. Alector has decided to discontinue the long-term extension trial (NCT05744401) following the disappointing results. The company intends to present detailed findings from the INVOKE-2 trial at a future scientific conference.
Strategic Shift and Workforce Reduction
In response to the trial outcome, Alector is implementing a strategic shift, including laying off approximately 17% of its workforce. This move is intended to align resources with the company's strategic priorities, focusing on its partnered monoclonal antibody programs, particularly the collaboration with GSK.
Alector reported having $457 million in cash reserves as of September 30, which the company anticipates will sustain operations through 2026.
Focus on GSK Collaboration
Alector is redirecting its resources towards its collaboration with GSK, which includes the development of latozinemab for frontotemporal dementia. Latozinemab is currently being evaluated in the pivotal Phase III INFRONT-3 trial (NCT04374136) for patients with frontotemporal dementia due to heterozygous mutations in the progranulin gene. Results from the INFRONT-3 study are expected in late 2025 or early 2026.
Another drug, AL101, also part of the GSK collaboration, is in Phase II development as a treatment for early Alzheimer’s disease. The PROGRESS-AD Phase II trial (NCT06079190) is currently recruiting participants and has reached over one-third of its target enrollment of 282 participants.
Broader Context in Alzheimer's Drug Development
Alector's setback follows a similar announcement from Cassava Sciences, which recently discontinued the development of its lead Alzheimer's treatment, simufilam, after it failed to meet primary endpoints in a Phase III trial. These recent failures highlight the challenges and complexities of developing effective therapies for Alzheimer's disease, a condition affecting millions worldwide.