With approvals from authorities in the U.S. and Europe, Valneva is set to advance its Lyme disease vaccine candidate into clinical testing on both sides of the Atlantic. It's the only candidate against the disease in development, but the U.S. government has specifically pledged to tackle it as expressed in the recently passed 21st Century Cures Act.
The vaccine, dubbed VLA15, targets the Outer Surface Protein A, one of the most dominant proteins expressed by the bacteria in a tick. Preclinical studies on mice showed that the vaccine can provide protection against the majority of Borrelia species.
Lyme disease is caused by the Borrelia bacteria usually transmitted to humans through the bite of ticks. Its early symptoms after infection include a neither itchy nor painful skin rash called erythema migrans, fever and headache, which if left untreated, could evolve into infections in joints, the heart and the nervous system.
The first and only licensed vaccine used three doses to fight Lyme disease and was made by what’s now GlaxoSmithKline. Even though it showed about 80% effectiveness, LYMErix, licensed in 1998, was voluntarily withdrawn from the market by 2002 because of safety concerns over its possible relationship to autoimmune arthritis. The company also chose to settle a class action lawsuit even though no study has ever corroborated the hypothesis.
VAL15 uses the same basic idea as LYMErix, but is trying to tackle bacteria species not just found in the U.S. but also in Europe, which LYMErix failed to cover. The phase 1 trials will be carried out on 180 individuals at two sites in the U.S. and Belgium.
Another Lyme candidate developed by Pasteur Mérieux Connaught never sought licensure even though phase 3 data were positive. A small market size was cited as a reason to abandon the project.
However, Lyme disease has gained pace in the U.S. and Europe in recent years. In 2009, the CDC listed the disease among the top 10 notifiable conditions in the U.S., together with other vaccine-preventable diseases like varicella and pertussis. That year, Lyme disease reached a peak of 29,959 cases as reported by the CDC. In 2015, 28,453 cases were confirmed.
Based in France, Valneva also has Dukoral, a cholera vaccine acquired in 2015 from Crucell Holland, part of Johnson & Johnson’s Janssen, and a Japanese encephalitis vaccine marketed under the trade names Ixiaro and Jespect. Also in its pipeline is a Zika vaccine candidate generated on the Ixiaro platform; the company is seeking a partner to advance the candidate into clinical trials after receiving positive feedback from the European Medicines Agency.