This excerpt taken from the ELN 20-F filed Feb 26, 2009.
AN-1792, a prototype active vaccine
The first drug development candidate to be evaluated in clinical trials under the collaboration with Wyeth, AN-1792 (an immunoconjugate vaccine), was discontinued in 2002 when a subset of patients (6%) developed a type of brain inflammation. We believe the AN-1792 program played a major role in advancing the understanding of the relationship between beta amyloid and Alzheimers disease, and has contributed to a growing body of scientific evidence pointing to the promise of immunotherapy as a potential treatment for Alzheimers disease.
Long-term follow-up data presented in 2007 evaluated participants from the AN-1792 Phase 2 clinical trial and found that 4.5 years after dosing had stopped, patients who had responded to treatment by generating anti-Aß antibodies continued to show significantly slower decline, compared to placebo patients, on two key measures of patient function: the Disability Assessment for Dementia and the Dependence Scale.