(May 31, 2023, Kunming) Walvax Biotechnology Co., Ltd. ("Walvax", 300142.SZ) announced that safety as well as short- and long-term immune response data from the Phase 2 clinical trial 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 Human Vaccines & Immunotherapeutics on May 30, 2023 (See full text at https://doi.org/10.1080/21645515.2023.2209001). The Phase 2 clinical study was initiated in 2013, on the basis of safety and preliminary immunogenicity profile demonstrated in the Phase 1 trial, of which results have been released in Vaccine (See full text at https://doi.org/10.1016/j.vaccine.2023.04.009), further evaluating neutralizing antibodies induced at 1 month following 3 doses of Walrinvax™ as the primary endpoint, as well as adverse events (AEs) observed among Chinese females aged 9-45 years, with immune persistence explored in those aged 9-17 years. Key findings of the phase 2 clinical study are as below: 

Walrinvax™ induces high levels of neutralizing antibodies against HPV 16 and 18 at 1 month post 3 doses (Month 7) in females aged 9-45 years

• Vaccinees demonstrated a marked response against both HPV16 and 18 by Month 7, with seroconversion rates (SCR) of ~100% observed across all age strata (9-17 years, 18-26 years, and 27-45 years).
• Higher GMTs were noted in the younger group. GMTs were the highest in subjects aged 9-17 years (8571 and 5826 for HPV types 16 and 18, respectively), which were 3.4- and 2.3-fold higher than those in subjects aged 27-45 years, suggesting promising protection incurred by Walrinvax™ in the target population for massive vaccination campaigns.
• Responses persisted in all age groups until Month 12.

Walrinvax™ yields protection up to 4 years after Dose 1 given among girls aged 9-17 years

• Seropositivity rates maintained at 98.5% and 97.6% against HPV types 16 and 18, respectively, during the 4-year long-term follow-up, verifying persistence over 48 months of the neutralizing antibody responses in subjects injected with the first dose at the age of 9-17 years.

Walrinvax™ is well-tolerated in females across all age groups

• The most frequently reported solicited local reaction was injection site pain, with an incidence rate of 16.5% and 11.8% in Walrinvax™ and placebo recipients, respectively; and the most common systemic reaction was fever, reported by 35.2% and 35.7%   participants in Walrinvax™ and placebo groups, respectively, most of these were transient.
• Incidence rates of AEs decreased as the number of doses increased.
• The severity of AEs was generally mild and moderate, and few were categorized as grade 3. No vaccine-related SAEs were reported throughout the 12-month follow-up period.

About the Phase 2 Clinical Study (311-HPV-1002)

The Phase 2 clinical study 311-HPV-1002, registered on clinicaltrials.gov (NCT02740790), was a randomized, double-blind, placebo-controlled study with 1200 healthy females aged 9–45 years enrolled in Guangxi, China, who were stratified into 3 age cohorts (600 aged 9–17 years; 240 aged 18–26 years; 360 aged 27–45 years) and randomized in a 1:1 ratio to receive 3 doses of Walrinvax™ or placebo in a 0, 2, 6 months schedule. Participants were observed for at least 30 minutes for immediate adverse reactions following each dose. Solicited local and systemic adverse reactions (ARs) within 7 days post each vaccination were monitored using diary cards. Unsolicited adverse events (AEs) within 30 days following each vaccination were collected and SAEs were followed up through 6 months after full-course vaccination (Month 12). Blood samples for immunogenicity assessment were obtained at baseline, 1 month after full-course vaccination (Month 7), and 6 months after full-course vaccination (Month 12) to measure anti-HPV neutralizing antibody using a pseudovirion-based neutralizing assay (PBNA). In addition, to further evaluate the immune persistence, after unblinding at the follow-up in Month 12, additional blood samples were collected at Months 24, 36, and 48 from subjects in 9-17 years cohort.

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.