Pfizer Inc and Johnson & Johnson scrapped further studies of one of the most anticipated experimental drugs for Alzheimer's disease after it failed to help patients with the memory-robbing condition in a second high-profile clinical trial.
The companies said they would discontinue all other studies of the drug bapineuzumab in its intravenous (IV) form, including two more late stage trials and follow-up extension studies, in patients with mild to moderate Alzheimer's.
The result marked the second such late-stage failure announced in recent weeks and was especially disappointing as bapineuzumab had been given a better chance of success in the patients studied in the second trial.
If successful, bapineuzumab would have been the first drug to fight the progression of the debilitating brain disease.
Attention will now turn to solanezumab, a similar drug being developed by Eli Lilly & Co that is also considered a long-shot to succeed, but will still carry fading hopes at least until late-stage test results are released later this year.
Results expected in key Alzheimer's treatments
Bapineuzumab failed to improve cognitive or functional performance compared with placebo in patients who did not carry a variation of a gene called ApoE4, according to initial results of the Phase III study released late on Monday.
Pfizer on July 23 announced the failure in the first of four high-stakes trials, in patients with the ApoE4 gene variation. That trial was considered more of a long-shot based on poor results in earlier trials, but hopes were high that the data would prove more encouraging in ApoE4 non-carriers.
"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," Steven Romano, head of Pfizer's Medicines Development Group, said in a statement.
Earlier stage treatment seen as critical
While the bapineuzumab IV program is dead, the companies said a Phase II study of a subcutaneous version of the drug would continue. There were no plans at this time to study the drug in asymptomatic patients or those with an earlier stage form of the disease, a spokeswoman for Pfizer and J&J said.
Many scientists and researchers believe any treatment to be successful must be used at a very early stage of the disease or even before it occurs in high-risk patients. Most had expected the late-stage studies of bapineuzumab would fail because they were treating patients whose brains were already damaged.
Dr. Sam Gandy of the Alzheimer's Disease Research Center at Mount Sinai School of Medicine in New York said in an email he "would have loved to have been pleasantly surprised and wrong," but he is neither.
William Thies, chief scientific officer of the Alzheimer's Association, said despite the trial failures he was anxious to see a full analysis of the results.
"These studies are terribly important for us to learn about Alzheimer's disease, and that part of the process is just starting as the data continues to be crunched in a variety of ways," Thies said.
He said the results in mild to moderate patients would not necessarily exclude bapineuzumab from prevention trials, such as the Dominantly Inherited Alzheimer's Network (DIAN) - a consortium that enrolls people who are genetically predisposed to develop the disease at an early age. The drugs to be used in that study are expected to be announced by year's end.
"One of the strong thoughts in the field is that you really have to treat people before they become demented," said Thies, noting that is the point of the DIAN study. "Out of hand this does not automatically exclude bapineuzumab from that study."
Wrong approach?
Bapineuzumab IV is an injectable monoclonal antibody that works by attacking a protein called beta-amyloid that is believed by many researchers to be a leading cause of Alzheimer's disease.
Alzheimer's is the most common form of dementia and the sixth leading cause of death in the United States. An estimated 5 million Americans are believed to have the disease. An estimated 36 million people worldwide are believed to have dementia, including Alzheimer's disease.
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