Findings: Bapineuzumab IV (bapineuzumab) is an antibody that targets the toxic beta-amyloid protein. It is being tested for the treatment of mild-to-moderate Alzheimer's disease in four clinical trials led by Janssen Alzheimer Immunotherapy R&D LLC (Janssen AI) and Pfizer, Inc. In one study led by Janssen AI (called study 302), it was reported that the participants who had the ApoE4 gene showed no discernible improvement in their cognitive performance or laboratory tests when treated with bapineuzumab as compared to those who received a placebo (non-bapineuzumab containing) treatment.

Significance: This particular drug candidate doesn't appear to be an effective treatment strategy for people who have Alzheimer's disease and are carrying the ApoE4 gene. However, these findings don't exclude the possibility that this drug could be an effective treatment for people without the ApoE4 gene variation. The results from three other phase III clinical studies on bapineuzumab treatment for Alzheimer's disease are still being analyzed and should be released before the end of this year. There is still hope that bapineuzumab may be shown to be effective for the estimated 70-75% of Americans who have Alzheimer's disease and don't have the ApoE4 gene.

For descriptions of all four clinical trials, including site locations, visit ClinicalTrials.gov:

• Study 301: NCT00574132 http://clinicaltrials.gov/ct2/show/NCT00574132 (ApoE4 non-carriers)
• Study 302: NCT00575055 http://clinicaltrials.gov/ct2/show/NCT00575055 (ApoE4 carriers)
• Study 3000: NCT00667810 http://clinicaltrials.gov/ct2/show/NCT00667810 (ApoE4 non-carriers)
• Study 3001: NCT00676143 http://clinicaltrials.gov/ct2/show/NCT00676143 (ApoE4 carriers)

Extension to Studies 301 and 302 (Long-Term Safety and Tolerability Study):

• NCT00937352 http://clinicaltrials.gov/ct2/show/NCT00937352 (both ApoE4 carriers and non-carriers)

Press Release:

• Pfizer