A pill that kills ticks is a promising new weapon against Lyme disease


If you have a dog or cat, chances are you've given your pet a flavored chewable tablet for tick prevention at some point. What if you could take a similar pill to protect yourself from Lyme disease?

Tarsus Pharmaceuticals is developing a pill for humans – without the flavoring – that could provide protection against tick-borne disease for several weeks at a time. In February, the Irvine, Calif.-based biotech company announced results of a small, early-stage trial that showed the drug could kill ticks on people 24 hours after taking it, with effects lasting up to 30 days. .

“What we envision is something that will protect you before the tick even bites,” says Bobby Azamian, CEO of Tarsus.

Lyme disease is a rapidly growing problem in the United States, with approximately 476,000 people diagnosed and treated each year, according to the latest data from the Centers for Disease Control and Prevention. This number is likely much higher, as many patients are treated after a tick bite even if infection is not confirmed, but it underscores the burden of Lyme disease on the health care system—which researchers at the CDC and Yale University has invested approximately $1 billion per year.

This disease is caused by bacteria borrelia burgdorferi, which is spread to humans through the bite of an infected tick. In most cases, the tick has to stick around for about 36 to 48 hours before the bacteria can be transmitted. Symptoms include fever, headache, fatigue and a distinctive skin rash that looks like a bullseye.

Without a Lyme disease vaccine on the market, current prevention includes using insect repellents such as DEET and permethrin and wearing closed shoes, long pants, and long sleeves in a tick-infested area.

“We've seen rates of tick-borne diseases increase over the past few years, despite people being told to check ticks, use DEET, and apply permethrin to their clothes,” says Paul Auwerter, a professor at the Johns Hopkins University School of Medicine. ” Medicine that studies Lyme disease.

Auvater says a more effective treatment strategy would be welcomed, especially because Lyme disease can sometimes cause serious health problems. Antibiotics are usually effective when taken quickly, although symptoms may persist for weeks or months in about 5 to 10 percent of patients. If left untreated, the infection can spread to the joints and cause arthritis. It can also set up in the heart and nervous system, causing persistent fatigue, numbness, or weakness.

The experimental pill that Tarsus Pharmaceuticals is testing is a formulation of lotilaner, a drug that paralyzes and kills parasites by interfering with the way signals are passed between nerve cells. Lotilaner is already approved as a veterinary medicine under the brand name Credelio to control fleas and ticks in dogs and cats.

“Our animals have better options for tick prevention than we do,” says Linden Hu, a professor of immunology at Tufts Medical School who led the TARSUS trial. “There are lots of medications and vaccines available for dogs and cats, but there is nothing for us.”