A vaccine to combat Lyme disease has entered the third phase of a clinical trial, leading it one step closer to becoming what would be the only vaccine of its kind for use in humans in the United States.
The vaccine, which is being developed in a partnership between Pfizer and the French biotechnology company Valneva, has elicited a strong immune response in both adults and children from its Phase 2 studies, according to a news release by the two companies.
The Phase 3 trial is planned to enroll 6,000 participants age 5 and older at 50 sites in areas of North America and Europe where the disease, which originates in ticks, is highly endemic, according to Pfizer and Valneva.
The study will also be randomized and placebo-controlled with participants receiving three doses of the two companies’ VLA15 Lyme disease vaccine candidate or a saline placebo as a primary vaccination, followed by a booster dose of VLA15 or a placebo booster, the companies added.
VLA15 stands out as the only Lyme disease vaccine candidate currently in clinical development, according to Pfizer and Valneva. It targets the outer surface protein A, or OspA, of Borrelia burgdorferi, the bacteria in ticks which can cause Lyme disease.
“Blocking OspA inhibits the bacterium’s ability to leave the tick and infect humans,” Pfizer said. Most often a tick must be attached to a human for 36 to 48 hours in order for the bacterium to transmit, according to the CDC, which added that younger, smaller ticks — or nymphs — which are harder to spot and are most active in spring and summer, tend to be the culprits.
Lyme disease is considered the most common vector-borne illness in the Northern Hemisphere — annually affecting between approximately 476,000 people in the U.S. and 130,000 people in Europe, Pfizer and Valneva said.
Early symptoms of the disease include fatigue, fever, headache, mild stiff neck, joint stiffness and muscle aches and pains — which are often overlooking or misinterpreted as something else, the companies added.
There is also the characteristic bullseye-shaped skin rash called erythema migrans, the CDC said.
If Lyme disease is left untreated, infection can spread to a person’s joints, heart and nervous system, according to the CDC, where it can cause facial palsy, arthritis, heart problems, and several other serious effects. Most cases can be treated successfully with a few weeks of antibiotics, especially if acted on promptly.
The blacklegged tick, or deer tick, is most responsible for the spread of the disease, and is mostly isolated to the northeast, mid-Atlantic and north-central regions within the United States, the CDC said. The western blacklegged tick is also able to spread the disease on the West Coast.
“The medical need for vaccination against Lyme disease is steadily increasing as the geographic footprint of the disease widens,” Pfizer and Valneva said.
“With increasing global rates of Lyme disease, providing a new option for people to help protect themselves from the disease is more important than ever,” said Annaliesa Anderson, senior vice president and head of vaccine research and development at Pfizer, in a statement through her company and Valneva’s news release.
The U.S. used to have a marketed Lyme disease vaccine for humans called LYMERix, which was discontinued in 2002, according to the CDC.
The CDC noted that MassBiologics of the UMass Chan Medical School in Worcester has developed a human monoclonal antibody designed to be used as a pre-exposure prophylaxis, or PrEP, for Lyme disease — an approach which would provide seasonal protection against Lyme disease, likely consisting of a single shot a person would receive each year at the start of tick season.
The medical school said in May that Phase I of a clinical trial was nearing completion and would end in August and that the next trial phase might begin as soon as spring 2023, citing Mark Klempner, MD, a professor of medicine and the former executive vice chancellor for MassBiologics.
According to Klempner the shot could be licensed and available to the public in 2024.
For the VLA15 vaccine, should it prove safe and effective in the Phase 3 study, Pfizer and Valneva could submit approvals to the FDA as well as to the European Medicines Agency in 2025, the companies said.
“We look forward to further investigating the VLA15 candidate in Phase 3, which will take us a step closer to potentially bringing this vaccine to both adults and children who would benefit from it,” said Juan Carlos Jaramillo, the chief medical officer of Valneva in a statement.
This content was originally published here.
