Dr. Mark Klempner, a professor of medicine at the University of Massachusetts, has developed a drug that may prevent Lyme disease from infecting humans. The drug, known as Lyme PrEP, was approved for its first human clinical trial by the Food and Drug Administration (FDA) at the end of 2020.
Approximately 60 volunteers have been recruited for the first round of trials, which will take place in Lincoln, Neb. Lincoln was chosen due to the fact that Lyme disease is rare in the area, reducing the chances that a subject may already have the bacteria from a previous infection and have developed responses that could confuse the results.
“There is a real unmet public health need for the prevention of Lyme disease,” Klempner said in a press release.
In the United States, Lyme disease is the most common vector-borne disease (illnesses caused by parasites, bacteria, and viruses transmitted to humans from living organisms). The Centers for Disease Control and Prevention (CDC) estimates that approximately 476,000 citizens are infected with the disease annually.
In comparison, Canada has much smaller numbers, but there has been a major jump over the last 10 years as cases rose from 144 in 2009 to 2,636 in 2019.
The disease is caused by Borrelia burgdorferi, a bacterium transmitted to humans through the bite of an infected black-legged tick. Early stage Lyme disease can result in fever, headache, fatigue, and rash. If left untreated, it can lead to arthritis and facial paralysis. Experts advise deterring ticks with bug spray and being vigilant about quickly removing them from exposed skin. However, if you are infected, most cases can be treated with two to four weeks of antibiotics.
Klempner’s Lyme PrEP, which would be administered as a seasonal shot, meaning it would need to be injected annually, is designed to provide immediate protection, circulating through the bloodstream and killing the bacteria from a tick bite before the infection takes hold.
Unlike a vaccine, which delivers an inactive part of the disease, triggering a person’s immune system to create antibodies, Lyme PrEP, which is known as a pre-exposure prophylaxis (PrEP), delivers a single anti-Lyme antibody.
“There are more than 30 years of clinical experience that says a monoclonal antibody will be safe,” Klempner said.
While Klempner’s Lyme PrEP has so far proven effective, it isn’t the first drug to tackle Lyme disease. In 1998, the FDA approved a vaccine called Lyme Rx that targeted the outer protein of the Borrelia burgdorferi bacteria. There was, however, uncertainty around the vaccine’s length of immunity and it required multiple injections throughout the year, causing Lyme Rx to be removed from the market in 2001.
“Through our research, we realized that just one of the antibodies that the human body developed after multiple injections of the Lyme Rx vaccine was sufficient to prevent infection,” Klempner said. “We identified the single antibody that led to immunity and tested it in animals where it proved 100 percent effective.”
Moving into the first round of clinical trials, Klempner said the goals are to test for the safety of Lyme PrEP and to determine how long it lasts in the human bloodstream. Assuming the tests go as planned, it’s predicted that Lyme PrEP could be available by 2023.