Even After Alzheimer's Drug Trial is Halted, Hope Still Remains for New Treatments

Fresh on the heels of another failed drug trial, pharmaceutical companies try to gauge the remaining strategic options in the treatment of patients with Alzheimer’s disease.

Pfizer Inc and Johnson & Johnson’s humanized monoclonal antibody bapineuzumab was recently pulled from development after it failed to improve cognitive function in Alzheimer’s disease patients. The news about bapineuzumab highlights the issue of whether researchers and manufacturers should continue pursuing current approaches to treating the disease, or if a different therapeutic direction is needed.

Future development of the intravenous form of bapineuzumab will not occur, but a newer subcutaneous version of the drug is in an early stage of research, according to Forbes’ Matthew Herper.

“While we are disappointed in the results of the two bapineuzumab IV studies, particularly in light of the urgent need for new advancements in Alzheimer's disease, we believe that targeting and clearing beta amyloid remains a promising path to potential clinical benefits for people suffering from this disease," said Husseini Manji, MD, head of neuroscience therapeutics for J&J's Janssen Research & Development, in a statement.

Although other recently released research supports the hypothesis that beta amyloid is a promising therapeutic target for Alzheimer’s disease, some sources have pointed out that the underlying problem with many of the drugs being created is that they aim to slow disease progression at a point far too late in the game, after plaques have already significantly damaged cognitive function.

Lilly's late-stage candidate solanezumab is one of the only drugs left in development focused on halting the progression of the disease, and like bapineuzumab, it targets plaque build-up in the brains of Alzheimer’s patients. Lilly’s drug targets floating plaque, whereas the Pfizer-J&J drug targets plaque deposits.

Another antibody-based drug, Genentech’s crenezumab, is being tested in healthy participants who are at high risk of developing Alzheimer’s disease. Hope for patients with Alzheimer’s could also come from new treatments like Baxter’s Gammagard, a type of intravenous immune globulin derived from the blood plasma of healthy individuals. Merck is developing MK-8931, a BACE inhibitor designed to prevent the buildup of plaque deposits by preventing amyloid precursor protein from turning into beta amyloid. Yet another drug, called bexarotene—which has been on the market for about 10 years to treat T-cell lymphoma—may help facilitate beta amyloid clearance from the brain. The tau theory of disease formation is also being investigated.

Lundbeck’s Lu AE58054 has a different mechanism of action than currently available Alzheimer's medications. It aims to improve cognition in Alzheimer’s by targeting 5-HT6 receptors in the brain. It is considered an augmentation therapy and is meant to be used in combination with donepezil. Late-stage trials for this treatment will begin later this year. Bloomberg reports that Lundbeck is in talks with numerous potential partners to help develop this drug further.