At the same time the full Phase 1 study population has been followed-up across all doses for up to one year, providing the final Phase 1 data.

The final Phase 1 data confirmed the safety and tolerability profile observed at all time-points, as reported in the interim analysis. VLA15 demonstrated a favorable safety profile and had no associated safety concerns.

In addition, the final Phase 1 immunogenicity results indicated that the alum-adjuvanted formulations elicit higher immune-responses at all time-points, confirming the interim data findings.

As expected, based on the interim Phase 1 data, antibody titres declined post Day 84 across all groups, trending towards baseline at approximately one year post initial vaccination.

To evaluate the benefit of a booster dose, 64 subjects across the two higher dose groups (48µg and 90µg, both with and without alum) from Phase 1 received a booster in the period 12 to 15 months after their initial dose in the primary immunization.

These single re-vaccinations resulted in a significant immune-response, yielding OspA antibody titres at levels 2.7-fold (ST3^[2]) - 5.8-fold (ST1) over the initial titres observed at Day 84 (geometric mean fold rise (GMFR)).

These results are in line with published data from other OspA-based Lyme vaccines that had previously been in development.

Wolfgang Bender, M.D., Ph.D., Chief Medical Officer of Valneva, commented,

"These encouraging results support our current development plans and hypothesis for our leading vaccine candidate, VLA15. As a result of these findings, we have included a VLA15 booster in the Phase 2 program that is now underway.

Addressing the significant, and growing, unmet medical need caused by Lyme disease is our top priority, VLA15 remains the only Lyme vaccine candidate in clinical development worldwide."

Valneva announced primary endpoint (interim) data from its Phase 1 trial of VLA15 (VLA15-101) in March 2018^[3].

Given the range of immune response and the variability across the different serotypes (seroconversion rates at Day 84 were between 71.4% (ST1) and 96.4%(ST2)), the ongoing Phase 2 study (VLA15-201) includes two higher doses (135 µg and 180µg, both adjuvanted with alum) and a study evaluating an alternative vaccination schedule (VLA15-202) is scheduled to commence mid-2019.

The complete Phase 2 study is expected to be approximately two years in duration with interim data (primary endpoint) expected mid-2020.

About the Phase 2 Clinical Study VLA15-201

VLA15-201 is the first of two planned, parallel Phase 2 studies. It is a randomized, observer-blind, placebo controlled trial conducted at trial sites in the US and Europe.

Initially, 120 subjects will receive one of three dosage levels of VLA15, or placebo, followed by a Data Safety Monitoring Board (DSMB) review of safety data.

Thereafter, 450 subjects will receive one of two dose levels of VLA15 (180 subjects each), or placebo (90 subjects), in the main study phase.

VLA15 will be tested as alum adjuvanted formulation and will be administered intramuscularly in three injections, at Days 1, 29 and 57.

Subjects will be followed for one year, with the main immunogenicity readout on Day 85 (primary endpoint).

The study is enrolling healthy adults 18 to 65 years of age.

Study centers will be located in areas where Lyme disease is endemic; subjects with a cleared past infection with Borrelia burgdorferi, the bacteria that cause Lyme disease, will also be enrolled.

About Lyme Disease

Lyme disease is a systemic infection caused by Borrelia bacteria transmitted to humans by infected Ixodes ticks^[4]. It is considered the most common vector borne illness in the Northern Hemisphere.

According to the U.S. Centers for Disease Control and Prevention (CDC), approximately 300,000 Americans^[5] are diagnosed with Lyme disease each year with at least a further 200,000 cases in Europe^[6].

Early symptoms of Lyme disease (such as a gradually expanding erythematous rash called Erythema migrans or more unspecific symptoms like fatigue, fever, headache, mild stiff neck, arthralgia or myalgia) are often overlooked or misinterpreted.

Left untreated, the disease can disseminate and cause more serious complications affecting the joints (arthritis), the heart (carditis) or the nervous system. The medical need for vaccination against Lyme disease is steadily increasing as the disease footprint widens^[7].

About VLA15

Valneva's vaccine candidate, VLA15, is currently the only active vaccine program in clinical development against Lyme disease. The program was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) in July 2017^[8]and Valneva reported positive interim Phase 1 results in March 2018^[9].

VLA15 showed a favourable safety profile and was immunogenic in all doses and formulations tested with good OspA-specific IgG antibody responses against all OspA serotypes.

VLA15 is a multivalent, protein subunit vaccine that targets the outer surface protein A (OspA) of Borrelia.

It is designed for prophylactic, active immunization against Lyme disease aiming for protection against the majority of human pathogenic Borrelia species.

VLA15 is designed to confer protection by raising antibodies that prevent Borrelia from migrating from ticks to humans after a bite.

The safety profile is expected to be similar to other vaccines using the same technology that have been approved for active immunization in adults and children.

The target population includes individuals at risk above 2 years of age living in endemic areas, people planning to travel to endemic areas to pursue outdoor activities and people at risk who have a history of Lyme disease (as infection with Borrelia does not confer protective immunity against all pathogenic Borrelia species).

Vaccination with OspA was already proven to work in the 1990s and VLA15 pre-clinical data showed that the vaccine has the potential to provide protection against the majority of the Borrelia species pathogenic for humans^[10].

About Valneva SE

Valneva is a biotech company developing and commercializing vaccines for infectious diseases with major unmet needs. Valneva's portfolio includes two commercial vaccines for travelers: IXIARO^®/JESPECT^® indicated for the prevention of Japanese encephalitis and DUKORAL^® indicated for the prevention of cholera and, in some countries, prevention of diarrhea caused by ETEC.

The Company has various vaccines in development including a unique vaccine against Lyme disease.

Valneva has operations in Austria, Sweden, the United Kingdom, France, Canada and the US with over 450 employees. More information is available at www.valneva.com.