Sanofi, SK Bioscience Launch Phase III Trial Program to Develop PCV21 for Pneumococcal Conjugate Vaccines

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Sanofi and SK Bioscience announced that they have entered a new collaboration to develop next-generation pneumococcal conjugate vaccines (PCVs) targeting both pediatric and adult populations. According to Sanofi, the joint venture aims to address invasive pneumococcal disease (IPD), driven by serotypes not covered by existing vaccines.

As part of the collaboration, Sanofi and SK will initiate a Phase III trial for PCV21 following positive Phase II results reported in 2023. The new program is expected to include over 7,700 infants, toddlers, young children, and adolescents across the United States, Europe, Australia, Asia, and Latin America.¹

“Given the vast unmet public health needs in IPD, we’re delighted to expand this collaboration and continue our pursuit of innovative work in PCV. Our collaboration leverages SK bioscience’s capabilities and Sanofi’s expertise in developing and bringing innovative vaccines to people worldwide with the collective aim of reducing the global impact of pneumococcal disease,” said Thomas Triomphe, EVP, vaccines, Sanofi, in a press release.

Under terms of the deal, Sanofi will provide an upfront payment of approximately $51 million to SK and will also provide future development and commercial milestone payments. Both companies will co-fund research and development costs. While SK will maintain commercialization rights in South Korea, Sanofi will lead commercialization efforts globally, with SK receiving royalty payments on product sales outside South Korea.¹

In 2023, SK announced positive Phase II trial results for PCV21. The study, which enrolled 140 toddlers aged 12 to 15 months and 712 infants aged 42 to 89 days, demonstrated comparable immunogenicity of GBP410 compared to the control vaccine, following the primary vaccination at two, four, and six months of age as well as the booster vaccination for ages 12 to 15 months. Additionally, data from the trial demonstrated a well-tolerated safety profile, with a comparable reactogenicity profile to the control vaccine and no vaccine-related serious adverse events.²

"The successful Phase II clinical trials of pneumococcal conjugate vaccine signifies that SK bioscience's technology and capability in vaccine development can deliver best in class vaccine candidates,” said Ahn, in a press release.

"We're so proud to collaborate with an excellent partner, Sanofi, and we continue to be committed to developing and manufacturing vaccines based on the global partnership with major pharmaceutical companies.”

According to the Centers for Disease Control and Prevention, children younger than five years of age and adults over 65 years of age are at increased risk for pneumococcal disease. Additionally, common conditions and risk factors include alcoholism; cerebrospinal fluid leak; chronic heart, kidney, liver, or lung disease; cigarette smoking; cochlear implant; decreased immune function from disease or drugs; diabetes mellitus; and chronic lung conditions such as chronic obstructive pulmonary disease, emphysema, and asthma. While it is currently unknown why, individuals of African American, Alaska Native, or American Indian descent have increased rates of pneumococcal disease.³

According to the World Health Organization, there are two classes of pneumococcal vaccines currently available, with one based on olysaccharides and the other based on polysaccharides conjugated to a carrier protein. They noted that the e polysaccharide vaccine consists of purified capsular polysaccharides from the 23 serotypes causing about 90% of invasive pneumococcal infection in industrialized countries. Responses are age-dependent and serotype-dependent.⁴

“We’re thrilled about the expansion of our collaboration with Sanofi, which serves as the core of our strategy to develop new solutions to combat pneumococcal disease. The ongoing expansion of our state-of-the-art manufacturing base, cofinanced by Sanofi, will support launch of PCV21 and future next generation vaccines,” said Jaeyong Ahn, CEO, president, SK Bioscience, in the press release.

References

1. Press Release: Sanofi initiates phase 3 program for PCV21 and expands collaboration with SK bioscience for next-generation pneumococcal conjugate vaccines. Sanofi. December 23, 2024. Accessed January 3, 2025. https://www.sanofi.com/en/media-room/press-releases/2024/2024-12-23-06-00-00-3001006

2. SK bioscience-Sanofi Announce Positive Results from Phase II Study of 21-Valent Pneumococcal Conjugate Vaccine Candidate. PR Newswire. June 29, 2023. Accessed January 3, 2025. https://www.prnewswire.com/news-releases/sk-bioscience-sanofi-announce-positive-results-from-phase-ii-study-of-21-valent-pneumococcal-conjugate-vaccine-candidate-301867294.html

3. Clinical Overview of Pneumococcal Disease. CDC. Accessed January 3, 2025. https://www.cdc.gov/pneumococcal/hcp/clinical-overview/index.html

4. Pneumococcal Disease. WHO. Accessed January 3, 2025. https://www.who.int/teams/health-product-policy-and-standards/standards-and-specifications/norms-and-standards/vaccine-standardization/pneumococcal-disease#:~:text=Two%20classes%20of%20pneumococcal%20vaccines,reducing%20transmission%20in%20the%20community.