Pfizer Experimental Alzheimer’s Drug Shows Promise in Early Data

  • Healthy volunteers in studies see reduction of beta amyloid
  • Next step will be testing patients with disease, company says

An experimental drug from Pfizer Inc. decreased production of a toxic protein that’s blamed for the development of Alzheimer’s disease, studies of healthy volunteers found, making the medication the first of its kind to emerge from early-stage research.

The drug works by modulating gamma secretase, an enzyme used to produce different types of beta amyloid, the protein that forms plaques in the brain that are a hallmark of Alzheimer’s. There were no serious or severe side effects from the medication, according to data presented Thursday by the New York-based drugmaker at the annual Clinical Trials on Alzheimer’s Disease conference in San Diego.

In a 22-patient study, volunteers getting the drug saw production of a toxic form of the protein decrease by as much as 39 percent after a single dose. A second study involving six groups of 10 participants each, treated daily for two weeks, found a 59 percent reduction in the protein known as abeta42 for those getting the highest dose.

The next step will be to test the drug in patients with Alzheimer’s, said Robert Alexander, Pfizer’s vice president for neuroscience research.

“This is a promising mechanism,” he said. “What the field hasn’t had up to this point is a gamma secretase modulator that’s made it all the way through phase one that can be tested in patients.”

Alzheimer’s remains a leading cause of death in the U.S., and scientists were dealt another blow last month after Eli Lilly & Co.’s experimental drug solanezumab failed in a late-stage trial. Pfizer’s latest drug, called PF-06648671, is using a novel approach to try to modulate the activity of gamma secretase. Earlier medicines designed to inhibit the enzyme completely, called gamma secretase inhibitors, worsened patients’ cognition and ability to carry out day-to-day activities. 

Other companies also have researched gamma secretase modulators, including Biogen Inc. and AstraZenca Plc.

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