May 11, 2022, Kunming — Walvax Biotechnology Co., Ltd. ("Walvax", 300142.SZ) announced the publication of results for the immunogenicity and safety profile of PCV13, the 13-valent Pneumococcal Polysaccharide Conjugate Vaccine, administered as an infant series at 3, 4, 5 months of age and a booster dose at 12-15 months of age in Chinese infants as part of the randomized, multi-center, double-blind, and positive-controlled phase 3 clinical trial in China to demonstrate the non-inferior immune responses and safety of PCV13 as compared to Pneumococcal 7-valent Conjugate Vaccine [Diphtheria CRM197 Protein] ("PCV7"). The results were published in Frontiers in Microbiology on May 09, 2022 (See full text at https://www.frontiersin.org/articles/10.3389/fmicb.2022.870973/full). Key findings of the phase 3 clinical study are shown below:

Potent immune responses post the primary series:

A total of 1,040 healthy infants were and randomized in 1:1 ratio to receive either PCV13 or PCV7 in a 3-dose primary regimen at 3, 4, 5 months of age, respectively. Serotype-specific IgG levels were measured using the standardized enzyme-linked immunosorbent assay (ELISA) method, and functional antibodies against each of the 13 serotypes were measured by the opsonophagocytic activity (OPA) microcolony assay in a subset of 200 subjects.

•  For the 7 commons serotypes, non-inferiority was demonstrated in terms of the proportion of responders with anti-pneumococcal polysaccharide IgG antibody concentration ≥0.35 mg/mL. The proportion of subjects who reached OPA antibody titers ≥1:8 against common serotypes was comparable between arms.
•  For the 6 additional serotypes, non-inferiority was demonstrated with regard to the proportion of IgG responders. Moreover, IgG GMCs for the six additional serotypes in the PCV13 group were superior to those in the PCV7 group. PCV13 induced significantly higher functional antibody responses to additional serotypes than PCV7, in terms of both the proportion of responders and OPA GMTs.

Pronounced boostability following the booster dose:

A booster dose was given between the ages of 12 and 15 months following the infant series. Before the booster dose, the proportion of subjects who had a pneumococcal IgG concentration ≥0.35 mg/mL or OPA antibody titers ≥1:8 had decreased substantially. The booster dose induced a significant increase in regard of not only the proportions of IgG/OPA responders but also the absolute values (GMCs or GMTs), suggesting the great significance of intensifying the immune responses with the booster dose.

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Favorable safety post vaccination:

The most frequent local reactions were redness and pain, and the most commonly reported systemic events were fever and diarrhea post each dose. The majority of reported local reactions and systemic events were mild or moderate in severity. Throughout the trial, the incidence of SAEs was similar between arms, with only one SAE considered to be related to the study vaccine. No deaths were recorded during the study.

About the pivotal Phase 3 Clinical Study

The pivotal pre-licensure clinical trial, registered at www.clinicaltrials.gov (NCT02736240), was a randomized, multi-center, double-blind, positive-controlled study to evaluate the immunogenicity and safety of PCV13 in comparison to PCV7 in 2760 healthy children 2-71 months of age (at least 6 weeks of age) in China (PCV7 was marketed in China since 2008 through 2015, and was the only available pneumococcal conjugate vaccine in China when the trial initiated). Non-inferior immunogenicity was observed for all shared serotypes between PCV13 and PCV7, and superior immunogenicity was declared for the additional serotypes of PCV13 versus PCV7 in all age groups, based on the design following Recommendations to assure the quality, safety and efficacy of pneumococcal conjugate vaccines, Annex 3, TRS No 977, with comparable and acceptable safety profile demonstrated following vaccination.

About PCV13

PCV13 is a 13-valent Pneumococcal Polysaccharide Conjugate Vaccine developed by Yuxi Walvax Biotechnology Co., Ltd. The vaccine is formulated by compounding the capsular polysaccharide antigen of Streptococcus pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F, individually conjugated to tetanus toxoid carrier protein. PCV13-TT is presented in both vials (1×0.5 mL single human dose) and pre-filled syringes (1×0.5 mL single human dose). PCV13 has been marketed in China since May, 2020 with the indication to prevent invasive diseases caused by the 13 serotypes of Streptococcus pneumoniae, with the dosing regimen of 4-dose complete series given at 2, 4, 6 and 12-15 months (first dose could be given as early as 6 weeks of age) or at 3, 4, 5 and 12-15 months of age, or a 3-dose (2 months apart) catch-up schedule for children 7-11 months of age, or a 2-dose (2 months apart) catch-up schedule for children 12-23 months of age, as well as a single dose for children 2-5 years of age.

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, Walvax’s purpose is to help everyone live a healthy life.