Valneva's Lyme vaccine—the only active candidate out there—moves to phase 2

Tick Lyme
Valneva plans to finish a phase 2 study of the only active clinical Lyme disease vaccine candidate in about two years. (Pixabay)

On the back of positive phase 1 data, Valneva has started a phase 2 study on VLA15, currently the only Lyme disease vaccine candidate in active clinical development.

The midstage trial is designed to determine the optimal dose and schedule for adoption in pivotal efficacy studies. Valneva intends to test three dosage groups of the vaccine in an alum-adjuvanted formulation.

Initially, 120 subjects will receive one of three dosages of VLA15 for safety data review, according to the company. Then, two dosages will be chosen to move into the next stage, a three-arm test of those two dosages against placebo. 450 subjects will receive three injections about a month apart. Valneva also plans to evaluate the vaccine in a different immunization schedule.

This time, the study will be carried out at centers in U.S. and EU areas where Lyme disease is endemic, and subjects will include patients with past infection with Borrelia burgdorferi, the tick-borne bacteria that causes Lyme.

VLA15 is a protein subunit vaccine that targets the outer surface protein A (OspA) of six serotypes of B. burgdorferi.

VLA15 could become the first Lyme vaccine for humans since GlaxoSmithKline pulled LYMErix off the market in 2002, four years after reports of side effects tanked sales. Since then, the tick-borne disease has spread broadly, increasing the need for a preventative.

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VLA15 lacks the region of the proteins that some believed had caused the LYMErix adverse events, and in interim phase 1 readouts, VLA15 showed a solid safety profile. In the highest, adjuvanted dose group—which Valneva sees as the most promising dose—it induced OspA-specific antibody responses of 71.4% to 96.4% against the six serotypes, Valneva reported in March.

The French biotech previously told FierceVaccines that it's looking for a partner to share the estimated $350 million cost of getting the vaccine to market. GSK has an option to take over the vaccine or enter a co-development/marketing deal upon completion of phase 2, which is expected in about two years.

“Lyme disease cases in the U.S. have increased dramatically over the last 30 years or so, substantially increasing the costs for healthcare systems,” said Valneva’s chief medical officer, Wofgang Bender, M.D., Ph.D., in a statement. “As the disease footprint widens, the need for a vaccine to prevent this significant unmet medical need increases.”

In the U.S., a total of 42,743 confirmed and probable cases of Lyme disease were reported to the CDC in 2017, about 9% more than in 2016. However, the CDC cautions that the number might be larger, as “[s]tandard national surveillance is only one way that public health officials can track where a disease is occurring and with what frequency.”