(Nov 2, 2023, Kunming) Walvax Biotechnology Co., Ltd. (“Walvax”, 300142.SZ) announced that immunogenicity, immune persistence and safety data among adolescent girls and young women from the Phase 3b clinical trial (311-HPV-1004) of Walrinvax™, a prophylactic pichia pastoris-expressed bivalent (types 16 and 18) HPV vaccine developed by Shanghai Zerun Biotechnology Co., Ltd. (ZerunBio), a subsidiary of Walvax, were published in the journal Vaccine on October 27, 2023 (See full text at https://www.sciencedirect.com/science/article/pii/S0264410X23012240). The Phase 3b clinical study was conducted during 2016 to 2019, based upon efficacy, immunogenicity and safety results obtained from the pivotal Phase 3 clinical study (311-HPV-1003) regarding a 3-dose (Months 0, 2 and 6) regimen, further evaluating immune responses following a reduced regimen to administer Walrinvax™ in a 2-dose (Months 0 and 6) schedule among adolescent girls aged 9-14 years with the non-inferiority between 2-dose and 3-dose regimens to be demonstrated as the primary endpoint.

A 2-dose regimen is now recommended by WHO for girls aged 9-14 years, which is the primary target for HPV vaccination campaign. Optimization of the HPV schedule is expected to improve access to the vaccine, offering countries the opportunity to expand the number of girls who can be vaccinated and alleviating the burden of the often complicated and costly follow-up required to complete the vaccination series.

Key findings from the phase 3b clinical study are as below:

• Non-inferiority regarding GMTs of neutralizing antibodies as demonstrated by a criterion of lower limit of 95% CI > 0.5
  • 2 doses in 9-14 years vs. 3 doses in 18-26 years: GMTs of neutralizing antibodies against HPV 16 and HPV 18 were 8511 (95% CI: 7586–9550) and 7079 (6310–8128) in the 2-dose adolescent girl group compared with 5129 (4677–5754) and 2692 (2344–3090) in the young women group with GMT ratios of 1.62 (95% CI: 1.41–1.91) and 2.69 (95% CI: 2.19–3.24), respectively.
  • 3 doses in 9-14 years vs. 3 doses in 18-26 years: GMTs of neutralizing antibodies against HPV 16 and HPV 18 were 6457 (5754–7079) and 7413 (6457–8511) in the 3-dose adolescent girl group compared with 5129 (4677–5754) and 2692 (2344–3090) in the young women group with GMT ratios of 1.23 (1.07–1.45) and 2.82 (2.29–3.39), respectively.
• Persistent protection through 3 years following the first dose
  • GMTs of neutralizing antibodies against HPV 16 and HPV 18 were consistently comparable or higher in the 2- and 3-dose adolescent girl groups than the 3-dose women group up to Month 36 (30 months after the last dose).
  • From a peak at Month 7 (1 month after the last dose), there was a general decline until a plateau was reached at around Month 24 to 36.
• Well-performed safety and reactogenicity profile among both age groups
  • The most commonly noted solicited local and systemic reactions were local injection pain and fever (an axillary temperature >37°C), reported at similar rates in all three groups and all described as mild or moderate in severity.
  • Neither deaths nor SAEs related to vaccination were reported.

About the Phase 3b Clinical Study (311-HPV-1004)

The Phase 3b clinical study 311-HPV-1004, registered on clinicaltrials.gov (NCT02740777), was a randomized study conducted at 2 clinical study sites in Hezhou City and Zhongshan County of the Guangxi Zhuang Autonomous Region from February 2016 to July 2019. Healthy girls 9 to 14 years of age (N=600) were administered with Walrinvax™ in a 2-dose (Months 0 and 6) or 3-dose (Months 0, 2 and 6) regimen, and eligible women 18 to 26 years of age (N=300) were administered with Walrinvax™ in a 3-dose (Months 0, 2 and 6) regimen. The primary objective was to demonstrate non-inferiority in immune responses following 2 doses of Walrinvax™ in adolescent girls compared with the response following 3 doses of Walrinvax™ in young women. Non-inferiority comparison regarding immune responses following 3 doses in adolescent girls vs. young women was also verified as the secondary objective, with safety and reactogenicity profile of Walrinvax™ administered in different schedules yielded as well. The study was also extended to explore immune persistency through 3 years following the first dose, 30 months after the last dose. Participants were monitored for 30 minutes after each vaccination for any immediate reactions. Solicited local and systemic adverse reactions (ARs) within 7 days post each vaccination were monitored using diary cards. Any unsolicited adverse events (AEs) were recorded from enrollment to Month 7, and any serious adverse events (SAE) were recorded from enrollment to Month 12. Blood samples were obtained from all participants before administration at baseline and then at follow-up visits at Months 7, 12, 24 and 36 for the detection of neutralizing antibodies against HPV16 and HPV 18 using a pseudovirion-based neutralizing assay (PBNA).

About Walrinvax™ (Recombinant Human Papillomavirus Bivalent [Types 16, 18] Vaccine [Pichia pastoris])

Walrinvax™ is a non-infectious recombinant bivalent vaccine prepared from the purified virus-like particles (VLPs) of the major capsid (L1) protein of Human Papillomavirus (HPV) Types 16 and 18, developed by Shanghai Zerun Biotechnology Co., Ltd. (ZerunBio), one subsidiary of Walvax Biotechnology Co., Ltd. Walrinvax™ is presented as a single-dose of 0.5mL in a vial or pre-filled syringe (PFS) for intramuscular injection only, with 40 μg Human Papillomavirus Type 16 L1 protein and 20 μg Human Papillomavirus Type 18 L1 protein as active ingredients. Walrinvax™ is to be administered as a 2-dose schedule at 0, 6 months (for females 9-14 years of age only) or 3-dose schedule at 0, 2, and 6 months (for females 9-30 years of age). Walrinvax™ can be stored and transported at 2℃ to 8℃ with protection from light. The shelf life of the vaccine is 24 months.

Walrinvax™ has been listed as one of the available bivalent HPV vaccines according to Human papillomavirus vaccines: WHO position paper (2022 update).

About ZerunBio

Shanghai Zerun Biotechnology Co., Ltd. (ZerunBio) is an innovative biopharmaceutical company focusing on the research, development and manufacturing of new recombinant human vaccines. The company was founded in 2003 and is located in Zhanjiang Hi-Tech Park, Pudong New District, Shanghai. ZerunBio is a subsidiary of Walvax Biotechnology Co., Ltd.

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.