Meningococcal group B vaccine(Pfizer Inc.)

Delonix Bioworks, a clinical-stage biotechnology company based in Shanghai and Perth, has initiated first-in-human dosing of the DX-104 vaccine, a MenB OMV vaccine candidate built on the company’s proprietary OMV Plus platform. As per a clinicaltrials.gov listing, the Phase I clinical trial is a randomized, double-blinded, positive-controlled study evaluating safety and immunogenicity in healthy adults in Perth, Australia. The enrollment target is 30 with participants to receive DX-104 or Bexsero at months 0, 1, and 6, with primary completion expected in May 2027. DX-104 uses genetically engineered outer membrane vesicles to present bacterial antigens, targeting serogroup B Neisseria meningitidis. The specific molecular antigens displayed on the OMVs have not been disclosed. The first-in-human DX-104 trial also serves as a platform validation event for the OMV Plus technology, which Delonix intends to apply across a broader pipeline including vaccines for pertussis, N. gonorrhoeae, and K. pneumoniae. Research context The scientific rationale for an OMV-based meningococcal B vaccine rests on decades of clinical and immunological evidence. Outer membrane vesicles derived from N. meningitidis contain native surface proteins in their natural conformation, stimulating bactericidal antibodies—the accepted correlate of protection against invasive meningococcal disease. Earlier OMV vaccines developed for outbreak control in Norway, Cuba, and New Zealand demonstrated strain-specific efficacy but limited breadth. Advances in genetic engineering now allow modification of OMVs to display optimized or additional antigens and reduce reactogenicity. This trajectory underpins the OMV Plus platform, though peer-reviewed data specific to DX-104’s engineered antigen composition are not yet available. The current standard of care for MenB prevention centers on two licensed vaccines: GSK’s Bexsero, a four-component vaccine combining recombinant proteins (fHbp, NadA, NHBA) with an OMV component, and Pfizer’s Trumenba, a bivalent recombinant fHbp vaccine. Both have been in use since the mid-2010s. More recently, the field has consolidated around pentavalent combination products: Pfizer’s Penbraya (approved October 2023) and GSK’s Penmenvy (approved February 2025) each combine MenB and MenACWY components into a single vaccination series for individuals aged 10–25. Despite commercial validation—Bexsero reported approximately USD 1.58 billion in 2025 sales—gaps persist. Strain coverage estimates for existing vaccines vary by region, ranging from roughly 60% to 91%. Manufacturing complexity contributes to per-dose costs that limit access in low- and middle-income countries, where meningococcal disease burden is concentrated. Adolescent MenB vaccination rates in the United States remain around 30%-35%, well below MenACWY uptake. The WHO’s “Defeating Meningitis by 2030” roadmap has called for broader access to affordable MenB vaccines. Competitive landscape DX-104 enters a field where no novel MenB vaccine candidates beyond the established GSK and Pfizer franchises appear to be in late-stage clinical development. Bexsero and Trumenba remain the only MenB-specific vaccines with active clinical programs, primarily consisting of post-marketing and life-cycle management studies. An earlier nine-valent OMV vaccine (NonaMen, Norwegian Institute of Public Health) targeting multiple PorA subtypes completed early trials but is not currently recruiting. Regional outbreak-response OMV vaccines such as MeNZB and VA-MENGOC-BC are no longer in active development. The absence of clinical-stage competitors pursuing new OMV-based or recombinant MenB approaches means DX-104 occupies a relatively uncrowded space for a next-generation candidate, though it faces a long development timeline against entrenched products with extensive real-world evidence. The differentiation Delonix claims—broader strain coverage, simplified manufacturing, and lower cost—will require clinical data to substantiate. The company has not disclosed which antigens are engineered into its OMVs, making it difficult to assess immunological differentiation from Bexsero’s existing OMV component. Your email address will not be published. Required fields are marked * Comment * Name * Email * Website

SHANGHAI, Feb. 6, 2026 /PRNewswire/ -- Delonix Bioworks, a clinical-stage biotechnology company developing next-generation bacterial vaccines, recently announced that its Group B meningococcal (MenB) vaccine candidate, DX-104, has received Investigational New Drug (IND) clearance from China's National Medical Products Administration (NMPA). This follows the successful completion of Clinical Trial Notification (CTN) procedures and ethics committee approval in Australia in January 2026. Delonix plans to initiate Phase I clinical trials in the near term to evaluate the safety and immunogenicity of DX-104 in human subjects. Invasive meningococcal disease (IMD) is a life-threatening bacterial infection that disproportionately impacts infants, adolescents, and young adults. Serogroup B has emerged as a predominant cause of IMD globally, accounting for approximately 50% of cases with a rising prevalence trend. While vaccines like GSK's Bexsero® and Pfizer's Trumenba® have established the commercial and clinical value of MenB prevention—with Bexsero recording approximately $1.58 billion in sales in 2025—significant global gaps in access and strain coverage remain. DX-104 is an engineered MenB vaccine candidate developed using Delonix's proprietary OMV Plus® platform. The platform leverages precisely engineered outer membrane vesicles (OMVs) with intrinsic adjuvant properties to optimize immunogenicity. In preclinical studies, DX-104 induced robust serum bactericidal antibody (SBA) responses without the need for external adjuvants. Furthermore, DX-104 has achieved commercial-scale production with high batch-to-batch consistency, ensuring a reliable global supply chain as the candidate advances toward potential commercialization. "The dual regulatory clearances in China and Australia mark a transformative milestone for Delonix Bioworks as we transition into a clinical-stage company," said Qiubin Lin, CEO and Founder of Delonix Bioworks. "This is a crucial step in our global strategy to deploy engineered bacterial vaccines that are designed to be highly immunogenic, well-tolerated, and scalable. We are committed to addressing the urgent unmet medical needs of patients worldwide." About Delonix Bioworks Delonix Bioworks is a clinical-stage biotechnology company at the forefront of developing next-generation genetically engineered bacterial vaccines. Leveraging its proprietary OMV Plus® platform, the company produces high-yield, cost-effective, and precisely engineered outer membrane vesicles (OMVs) designed for superior antigen presentation and immunogenicity. Delonix is dedicated to advancing a robust pipeline of first-in-class and best-in-class programs addressing critical unmet needs, including vaccines for Meningococcal B, pertussis, gonorrhoeae, and K. pneumoniae. For more information, please visit or contact [email protected] SOURCE Delonix Bioworks 21% more press release views with Request a Demo