(July 5, 2023, Kunming) Walvax Biotechnology Co., Ltd. ("Walvax", 300142.SZ) announced that the journal Human Vaccines & Immunotherapeutics has published data from a post-licensure Phase 4 clinical trial in Mali regarding the safety and immunogenicity of its Group ACYW135 Meningococcal Polysaccharide Vaccine ("MPV ACYW135") as compared to a licensed meningococcal conjugate vaccine of the same valent (Menactra^® developed by Sanofi Pasteur) on July 4, 2023 (See full text at https://www.tandfonline.com/doi/full/10.1080/21645515.2023.2230829). The Phase 4 clinical study was conducted at the Centre pour le Développement des Vaccins du Mali (CVD-Mali), in Bamako, Mali during December 2020 to July 2021, to discuss the immunogenicity and safety profile in healthy children 2-10 years of age.

Walvax MPV ACYW135 was launched on March 23, 2012 in China for active immunization against meningococcal diseases caused by serogroups contained in the vaccine (A, C, Y and W), and has so far been registered in additional 8 countries, with exportation to 14 countries. Over 12 million doses have been distributed worldwide since its first licensure in 2012. Upon the non-inferiority regarding proportions of subjects with rSBA titers ≥ 128 demonstrated in the Phase 4 clinical trial, Walvax MPV ACYW is now the only available polysaccharide vaccine proved to be non-inferior to a WHO-prequalified conjugate vaccine (Menactra^® from Sanofi Pasteur) with comparable and good safety profile demonstrated.

Key findings of the phase 4 clinical study are as below: 

One dose of Walvax MPV ACYW induces non-inferior immune responses as compared to Sanofi Pasteur Menactra^® at Day 30 post vaccination

• Non-inferior immunogenicity of Walvax MPV ACYW135 as compared to Sanofi Pasteur Menactra^® was both demonstrated when comparing the percentages of subjects in each vaccine group with rSBA titers ≥ 128 (primary endpoint) and those achieving a rSBA ≥ 4-fold increase after vaccination as compared to baseline unadjusted titers (secondary endpoint)
• Proportions of subjects with rSBA titers ≥ 8 for all serogroups were similar between vaccine groups (P >0.05)
• Geometric Mean Titers (GMTs) and Geometric Mean Fold Increases (GMFIs) for all serogroups in both vaccine groups were similar between vaccine groups (P >0.05)

Walvax MPV ACYW135 showed a similar reactogenicity and safety profile to Sanofi Pasteur Menactra^®

• No immediate post-immunization reactions were observed
• Local and systemic post-immunization reactions for 7 days after immunization were overall few and similar between vaccine groups for severity and duration (P >0.05), all of which resolved without sequelae
• Unsolicited adverse events were similar in both vaccine groups for relationship to study vaccines, severity and duration (P >0.05)
• No SAE was reported during the study period

About Meningococcal Diseases
Meningococcal diseases are a group of diseases (including meningitis, sepsis, pneumonia, etc.) caused by infections with the bacterium Neisseria meningitidis (N. meningitidis), posing great burden on the public health system in countries with high endemic rates. A total of 12 serogroups have been identified so far based on the structure of their polysaccharide capsule, while only 6 (A, B, C, W, X and Y) cause invasive meningococcal diseases^[1]. The disease can progress quickly and is sometimes deadly to vulnerable populations at increased risk. Worldwide, at least 135,000 deaths were reported to be related to invasive meningococcal diseases (IMDs) annually^{[2, 3]}.

About the Phase 4 Clinical Study (MPV ACYW-004)
The Phase 4 clinical study MPV ACYW-004, registered on clinicaltrials.gov (NCT04450498), designed as a single-center, observer-blind, randomized, controlled vaccine trial in healthy subjects 2 to 10 years of age, was conducted at the Centre pour le Développement des Vaccins du Mali (CVD-Mali), in Bamako, Mali during December 2020 to July 2021. A total of 260 healthy children aged from 2 to 10 years with residence in the study area were enrolled and randomized 1:1 to receive one single intramuscular injection of either Walvax MPV ACYW135 vaccine or Sanofi Pasteur Menactra^®. Primary and secondary immunogenicity endpoints were assessed with blood samples taken on the day of vaccination and 30 days after vaccination. Samples were tested by serum bactericidal antibody assay using baby rabbit complement (rSBA) to A, C, Y, W meningococcal strains by the Vaccine Evaluation Unit, UK Health Security Agency, Manchester, UK. Subjects were observed for 30 minutes after vaccination for any immediate post-immunization reactions. Solicited local and systemic reactions within 6 days after vaccination as well as unsolicited adverse events between Day 1 and Day 30 after vaccination were collected by investigators through home visits or during on-site visits. Serious adverse events were collected and followed up for six months after vaccination.

About the Group ACYW135 Meningococcal Polysaccharide Vaccine
Group ACYW135 Meningococcal Polysaccharide Vaccine (MPV ACYW135) is a lyophilized vaccine of purified meningococcal capsular polysaccharides of groups A, C, Y and W135 Neisseria meningitides (N. meningitides), developed by Yuxi Walvax, one subsidiary of Walvax Biotechnology Co., Ltd. The MPV ACYW135 is supplied as a single dose vial of lyophilized powder, with corresponding single dose of diluent. Each dose of 0.5 mL contains 50 μg each of polysaccharide for serogroup A, C, Y and W135 as active ingredients. MPV ACYW135 vaccine is indicated for active immunization to prevent invasive meningococcal diseases caused by N. meningitidis serogroups A, C, Y and W135 in individuals aged 2 years and above who are at increased risk for meningococcal diseases as a single-dose regimen. MPV ACYW135 vaccine should be stored and transported at 2℃ to 8℃ with protection from light (with diluent stored and transported at 2℃ to 30℃). The shelf life of the vaccine is 24 months.

About Walvax

Founded in 2001, Walvax Biotechnology Co., Ltd. (Walvax) is a leading vaccine producer, engaged in research and development, manufacturing and distribution of safe and efficacious quality vaccines. Headquartered in China’s southwestern city Kunming in Yunnan Province, Walvax went to IPO in 2010 (300142.SZ) and started business expansion from traditional vaccines to innovative vaccines. With the vision of dedicating to be the pride domestically and the pioneer globally in the vaccine industry, producing efficacious, quality, innovative and affordable products to protect people from the world’s deadliest diseases, Walvaxs purpose is to help everyone live a healthy life. For further information please visit https://en.walvax.com/about-us/our-company and follow us on Twitter at @WalvaxBiotech and LinkedIn.

References:
1.    WHO. Meningococcal meningitis. 2021 [cited 2022 April 21]; Available from: https://www.who.int/news-room/fact-sheets/detail/meningitis.
2.    Rouphael NG, S.D., Neisseria meningitidis: biology, microbiology, and epidemiology. Methods Mol Biol, 2012. 799: p. 1-20.
3.    Epidemics of meningococcal disease. African meningitis belt, 2001. Wkly Epidemiol Rec, 2001. 76: p. 282-288.