The revitalized field of immunotherapy has provided amazing benefits for patients with many types of cancers, and now it appears that these same revolutionary drugs may offer hope to patients with another debilitating disease: Alzheimer’s.
Recently, a study conducted by Israeli scientists showed that an immunotherapy drug can enable a stronger immune response that reverses the symptoms of Alzheimer’s, including clearance of the cerebral plaques that disrupt brain function, in mice that were genetically engineered to exhibit the disease.
The immunotherapy used in the study targets the PD-1 receptor on immune cells and belongs to a group of drugs known as checkpoint inhibitors. PD-1 checkpoint inhibitors prevent cancer’s ability to dampen the immune response, and treatment with them has led to remarkable outcomes in many cancer patients including former president Jimmy Carter. Checkpoint inhibitors enable a stronger, more durable immune response, whether against cancer cells or, in this case, the harmful proteins that cause Alzheimer’s neurodegenerative effects.
In this study, treating mice with the anti-PD-1 immunotherapy drug elicited an immune response that recruited macrophages, a type of immune cell, to the mice’s brains. There, the macrophages removed the damaging plaques, leading to improved brain function.
Note, however, that continuous treatment was required to maintain these effects long-term in the mice. Additionally, while it is important to remember that these results do not guarantee effectiveness in treatment of humans, as lead investigator Dr. Michal Schwartz notes, “with no cure or disease-modifying treatment for Alzheimer’s, the prospect of using PD-1 blockers may suggest short translation to the clinic.” This means that regulators may accelerate the time it will take to bring this FDA-approved drug into human trials for Alzheimer’s patients.
Hopefully future studies investigating immunotherapy’s mechanism of action against Alzheimer’s—through both in basic research as well as human clinical trials—will reveal even more about how the immune system can help defend our bodies against disease, and ultimately improve the lives of patients suffering from a whole spectrum of disorders.