MassBiologics of UMass Medical School has launched the first human clinical trial for Lyme PrEP, a novel pre-exposure prophylaxis designed to prevent Lyme disease, the most common vector-borne illness in the United States. The treatment, which utilizes a monoclonal antibody approach rather than traditional vaccine technology, could be available to the public as early as spring 2023.
The clinical trial has enrolled 66 volunteers in Lincoln, Nebraska, strategically selected in the Upper Midwest region to avoid testing on individuals who may have previously been exposed to Lyme bacteria, which could potentially confuse the trial results.
Addressing a Significant Public Health Burden
Lyme disease represents a substantial and growing public health challenge across the United States. According to a February study by the U.S. Centers for Disease Control and Prevention (CDC), while official surveillance reports capture between 30,000 and 40,000 cases annually, the actual number of Americans diagnosed with Lyme disease between 2010 and 2018 is estimated at approximately 476,000 per year—roughly ten times higher than officially reported figures.
The disease has shown particularly concerning trends in certain regions. The Maine Center for Disease Control announced in January 2020 that health providers had reported a record number of Lyme disease cases in 2019.
"There is a real unmet public health need for the prevention of Lyme disease," emphasized Dr. Mark Klempner, executive vice chancellor for MassBiologics and professor of medicine. "This is an exciting milestone."
Innovative Mechanism of Action
What distinguishes Lyme PrEP from traditional vaccines is its mechanism of action. Rather than stimulating the immune system to produce multiple antibodies, as vaccines typically do, Lyme PrEP delivers a single, human anti-Lyme antibody directly to the recipient.
"Through our research, we realized that just one of the antibodies that the human body developed after multiple injections of the LymeRx vaccine was sufficient to prevent infection," explained Dr. Klempner. "We identified the single antibody that led to immunity and tested it in animals where it proved 100 percent effective."
The antibody works by targeting and killing Borrelia bacteria in the tick's gut before they can migrate to the salivary glands and infect humans during a bite. Preclinical studies demonstrated that Lyme PrEP provides immediate protection upon injection as the antibody circulates through the bloodstream.
Advantages Over Previous Approaches
The approach represents a significant advancement over previous attempts to prevent Lyme disease. The FDA had approved a vaccine called LymeRx in 1998, but it was withdrawn from the market just three years later due to several limitations. That vaccine required multiple injections over a year before immunity developed, and questions remained about the duration of protection and the potential need for regular booster shots.
In contrast, Lyme PrEP is designed to provide immediate protection. Additionally, by using a single, defined antibody rather than inducing a broad immune response, researchers believe the treatment may reduce the risk of side effects.
"There are more than 30 years of clinical experience that says a monoclonal antibody will be safe," noted Dr. Klempner. "The bigger question we hope to answer is how long will the antibody last in the circulation so when a tick bites you will be protected from Lyme disease."
Clinical Trial Focus
The current trial is primarily focused on evaluating the safety profile of Lyme PrEP and its pharmacological properties, particularly how long the protective antibody remains in circulation after administration. This information will be crucial in determining the optimal dosing schedule for the treatment.
If successful, Lyme PrEP could represent a significant breakthrough in preventing a disease that affects hundreds of thousands of Americans annually and has proven challenging to diagnose, treat, and prevent using conventional approaches.
