A Phase 2b Non-Inferiority Clinical Study to Evaluate the Immunogenicity of SPVX02

  • Research type

    Research Study

  • Full title

    A Phase 2b, Randomised, Single-Blind, Non-Inferiority Clinical Study to Evaluate the Immunogenicity and Tolerability of SPVX02, a Tetanus and Diphtheria Booster Vaccine, Against Tetadif Comparator Vaccine in Healthy Adults

  • IRAS ID

    1014057

  • Contact name

    Karen O'Hanlon

  • Contact email

    kohanlon@stablepharma.com

  • Sponsor organisation

    Stablepharma Ltd

  • ISRCTN Number

    ISRCTN17148628

  • Clinicaltrials.gov Identifier

    NA

  • Research summary

    Stablepharma is developing a thermostable lyophilized tetanus and diphtheria (Td) vaccine (SPVX02) based on a reformulation of
    Tetadif vaccine. This Phase 2b study will be run in at least 1 site in England and aims to compare the immunogenicity and tolerability of SPVX02 against a comparator vaccine, Tetadif, using a randomised, single-blind design. The study aims to demonstrate that
    SPVX02 and Tetadif generate comparable anti-tetanus and anti-diphtheria post-boost immune responses in healthy
    adults. The study will be conducted in 160 healthy participants (aged 18-60) who have previously received a primary vaccination
    against tetanus and diphtheria but who have not received a booster vaccination in the last 10 years. Two cohorts of 80 participants
    will be randomised 1:1 in a single-blind manner to receive a single vaccination of either SPVX02 or Tetadif. The primary objective of the study is to compare post-dose antibody titres to obtain immunogenicity data (seroprotection rates). The secondary objectives of the study are to evaluate the tolerability of a single dose of SPVX02 or Tetadif, and to evaluate additional immunogenicity data (longer term seroprotection rates). Informed consent will be obtained before any study specific procedures are performed. Participants will be screened from Day -42 to Day 0. Eligible participants will attend the clinic to receive a single dose of SPVX02 or Tetadif on Day 1. On Day 1, an electronic diary , tape measure and thermometer will be provided to perform self-assessments of local and systemic safety and tolerability up to, and including, Day 7. Participants will have a follow-up telephone call on Day 2 (if required at the discretion of the site team based on their eDiary card entries at that time) and will return to the clinic for study assessments on Day 28. End of study visit procedures will be performed at the final clinic visit on Day 28.

  • REC name

    London - West London & GTAC Research Ethics Committee

  • REC reference

    26/LO/0388

  • Date of REC Opinion

    12 Jun 2026

  • REC opinion

    Further Information Favourable Opinion