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Poor results halt production, studies on promising Alzheimer's drug bapineuzumab

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(CBS News) A drug that many hoped would be an effective treatment for Alzheimer's disease has not lead to significant improvements for those with the disease, leading the manufacturers to halt development and further studies of its intravenous use.

Pfizer Inc. and Johnson & Johnson announced Monday that a recent Phase 3 trial of intravenous medication, bapineuzumab, in patients with mild-to-moderate Alzheimer's disease who did not carry the ApoE4 genotype did not reach hoped-for-results in improving cognitive and functional performance when compared to subjects who took the placebo.

Scientists think ApoE4 increases a person's chance of developing Alzheimer's and may worsen symptoms. Previous study results released on July 23 from a Phase 3 trial of the intravenous form of the drug on people who did have the ApoE4 genotype were also disappointing and showed no improvements when compared to the placebo, but scientists remained hopeful it would help people without the gene.

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"We are obviously very disappointed in the outcomes of this trial. We are also saddened by the lost opportunity to provide a meaningful advance for patients afflicted with mild-to-moderate Alzheimer's disease and their caregivers," Dr. Steven J. Romano, senior vice president, head, Medicines Development Group, Global Primary Care Business Unit, Pfizer Inc., said in the press release. "Yet these data, and the subgroup and biomarker analyses underway, will further inform our understanding of this complex disease and advance research in this field."

While no new safety issues were brought up because of the recent study, more serious, adverse side effects - including pneumonia, ARIA-E (amyloid-related imaging abnormalities like edema or effusion, or abnormalities observed in MRI scans), syncope or fainting, hip fracture and convulsions - were observed more often in patients who took bapineuzumab than those who took the placebo, on top of the disappointing results of the drug's efficacy.

The studies with the intravenous form of the drug have been discontinued, but all subjects will still have follow-up evaluations.

Bapineuzumab was developed Pfizer and Johnson & Johnson, with monetary contributions from Irish pharmaceutical company Elan, according to an earlier Pfizer press release. The drug supposedly worked to break down beta-amyloid, a protein that builds up in the brain creating a toxic plaque. Scientists believe that this amyloid plaque is what causes Alzheimer's, the New York Times reported.

According to the Associated Press, Johnson & Johnson said they would invest up to $1.5 billion on development of bapineuzumab in 2009. While the company will stop manufacturing the intravenous form of the drug, it will not stop developing the medication completely. An ongoing study where bapineuzumab delivered under the skin will continue as planned.

Many were hoping that the drug would be a new treatment because there hasn't been a new Alzheimer's drug on the market for nine years. Bapineuzumab was one of three promising new treatments - the others being Solanezumab by Eli Lilly and Co. and Gammagard by Baxter International Inc. - and some doctors believe that if all three drugs fail, it could be detrimental to future treatment prospects of people with the disease.

About 5.4 million Americans are living with Alzheimer's disease, according to the Alzheimer's Association. It is the sixth-leading cause of death, and is the only cause of death in the top 10 that cannot be prevented, cured or sold. In 2012, the cost of caring for Alzheimer's patients in America will total an estimated $200 billion.