A study to evaluate the tolerability and the effects on the immune system of a tetanus and diphtheria vaccine which does not need any cold chain distribution or storage
| ISRCTN | ISRCTN17148628 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN17148628 |
| Integrated Research Application System (IRAS) | 1014057 |
| Sponsor's protocol code number | SPL-SPVX02-02 |
| Sponsor | Stablepharma Ltd |
| Funder | Stablepharma Ltd |
- Submission date
- 08/05/2026
- Registration date
- 10/07/2026
- Last edited
- 10/07/2026
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
Plain English summary of protocol
Background and study aims
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).
Who can participate?
Healthy volunteers aged 18 - 60 years.
What does the study involve?
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.
What are the possible benefits and risks of participating?
Benefits:
Not provided at time of registration
Risks:
Risks include local and systemic reactions such as pain, redness, swelling at the injection site, fever, fatigue, headache, or more serious reactions (allergic or anaphylactic reactions). To mitigate this, all participants will be closely monitored for at least 30 minutes post vaccination.
Where is the study run from?
Medicines Evaluation Unit (UK)
When is the study starting and how long is it expected to run for?
June 2026 to February 2027.
Who is funding the study?
Stablepharma Ltd (UK)
Who is the main contact?
Karen O'Hanlon, kohanlon@stablepharma.com
Contact information
Scientific, Public
90 Victoria Street
Bristol
BS1 6DP
United Kingdom
| Phone | +44 07812606184 |
|---|---|
| kohanlon@stablepharma.com |
Principal investigator
The Langley Building, Southmoor Road
Manchester
M23 9QZ
United Kingdom
| Phone | +44 0161 9464071 |
|---|---|
| MKhan@meu.org.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Active |
| Assignment | Parallel |
| Purpose | Prophylaxis |
| Scientific 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 |
| Study objectives | Primary objective: To evaluate the seroprotection rates observed in sera collected from participants on Day 28 post-dose, following administration of a single dose of SPVX02 or Tetadif® Secondary objectives: 1. To evaluate the tolerability of a single dose of SPVX02 of Tetadif® 2. To evaluate the longer-term seroprotection rates observed in sera collected from participants on Day 28 post-dose, following administration of a single dose of SPVX02or Tetadif® 3.To evaluate the post vaccination Geometric Mean Titers (GMT) of anti-TT antibodies and anti-DT antibodies observed in sera collected from participants at Day 28 post-dose, following administration of a single dose of SPVX02 or Tetadif® |
| Ethics approval(s) |
Approved 12/06/2026, London - West London & GTAC Research Ethics Committee (2 Redman Place, Stratford, London, E20 1JQ, United Kingdom; +44 2071048098; westlondon.rec@hra.nhs.uk), ref: 26/LO/0388 |
| Health condition(s) or problem(s) studied | Tetanus and diphtheria preventative vaccination |
| Intervention | Two treatment groups of 80 participants will be randomised 1:1 using a paper-based randomisation process, in a single-blind manner to receive a single dose of SPVX02 or Tetadif®. Both treatment groups will be dosed in parallel and all participants will be followed up for 28 days post-vaccination. |
| Intervention type | Drug |
| Phase | Phase II |
| Drug / device / biological / vaccine name(s) | SPVX02 [Purified Diphtheria Toxoid PDT for human use, Purified Tetanus Toxoid PTT for human use] , Tetadif® [Purified Diphtheria Toxoid PDT for human use, Purified Tetanus Toxoid PTT for human use] |
| Primary outcome measure(s) |
Incidence of seroprotection resulting from a single dose of SPVX02 or Tetadif®, seroprotection is defined as an IgG serum antibody titre ≥0.1 IU/mL, which is the antibody titre level of anti-TT and anti-DT antibodies that are considered to confer protection against diphtheria and tetanus infection, measured using enzyme linked immunosorbent assays (ELISAs) at 28 days post-dose |
| Key secondary outcome measure(s) |
1. Incidence of safety and reactogenicity events which include:, adverse events, serious adverse events, incidence of local and systemic reactogenicity events observed for 7 days post-dose which include: pain, induration /swelling, tenderness, warmth, erythema at the injection site plus feverishness, chills, myalgia, fatigue, headache, arthralgia and rash |
| Completion date | 12/02/2027 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 60 Years |
| Sex | All |
| Target sample size at registration | 160 |
| Key inclusion criteria | 1. Participant is 18-60 years of age at the time of screening with a BMI ≤34.9 kg/m² 2. Participant is able to provide informed consent indicating that they are willing to participate and that they understand the purpose of the study and the assessments they are required to undergo as part of their involvement in the study 3. Participant is considered to be in good health with no current conditions that may significantly impair participant safety or influence the study results, as determined by the Investigator 4. Participant does not have any medical condition that causes primary or secondary immunodeficiency 5. Participant has previously received primary and/or booster immunisation with diphtheria and tetanus vaccines, as confirmed by GP records. Alternatively, in the absence of complete vaccination records, the participant has detectable screening tetanus and diphtheria antibody titres of ≥0.01 IU/mL 6. Participants who were born female and are of child-bearing potential must be practicing an acceptable, effective method of contraception for the duration of the study. Acceptable methods for this study include: 6.1. Hormonal contraception (use of hormonal contraception should start at least 28 days before the first administration of the study IMP) 6.2. Intrauterine device (IUD) 6.3. Intrauterine hormone-releasing system (IUS) 6.4. Bilateral tubal occlusion/ligation 6.5. Male or female condom with or without spermicide 6.6. Cap, diaphragm or sponge with a vaginal spermicide 6.7. Vasectomised partner (the vasectomised partner should be the sole partner for that volunteer and have received a medical assessment of surgical success) 6.8. Sexual abstinence (sexual abstinence is considered an effective method only if defined as refraining from heterosexual intercourse from signing the icf until the end of the study) 7. Participants who were born female and are not of child-bearing potential must be: 7.1. Postmenopausal: amenorrhea (no menstrual periods) for at least 12 months without an alternative medical cause 7.2. Permanently sterile: permanent sterilization methods include hysterectomy (removal of the womb), bilateral salpingectomy (surgical removal of the fallopian tubes), and bilateral oophorectomy (surgical removal of both ovaries). 8. Male participants must be willing to use a contraception method upon enrolment, during the course of the study, and for 1-month post-dose |
| Key exclusion criteria | 1. Serious and uncontrolled chronic disease (i.e., cardiac, pulmonary, renal, neurologic, metabolic, rheumatologic, etc.) 2. Known or suspected autoimmune disease or impairment of immunological function of any cause. Immune-mediated conditions that are stable and well-controlled (e.g.. Hashimoto thyroiditis) as well as those that do not require systemic immunosuppressants (e.g.. asthma, psoriasis, or vitiligo) may be permitted at the discretion of the Investigator and following discussion with the Medical Monitor. In participants with stable, treated hypothyroidism, mildly abnormal thyroid function tests may not be clinically significant and may be accepted at the discretion of the Investigator 3. Acute medical illness, with or without fever, or an oral or tympanic temperature >38°C within the 72 hours prior to dosing 4. Administration of immunoglobulin or other blood products within the last three months prior to screening; administration of corticosteroids (injected or oral) or other immunomodulatory therapy within 42 days prior to Day 1 5. A positive test result at screening for HIV, hepatitis C virus or hepatitis B virus. HIV-positive participants on antiretroviral therapy with CD4 count ≥500 cells/mm3 and HIV RNA ≤500 copies/mL within the past 365 days, are permitted at the discretion of the Investigator. Hepatitis C or Hepatitis B infection, if well controlled on stable therapy, with normal liver function and no evidence of immunosuppression, may be permitted at the discretion of the Investigator and following discussion with the Medical Monitor 7. History of allergic disease or any suspected or known hypersensitivity to any of the SPVX02 or Tetadif components 8. Any history of anaphylaxis in reaction to a vaccination 9. Unable to attend scheduled visits or unable to comply with the study procedures 10. Enrolled in another interventional clinical study or has received an investigational intervention in the last 6 months, or within 5 half-lives, whichever is longer 11. Any condition that would pose a health risk to the participant or interfere with the evaluation of either vaccine in the opinion of the Investigator 12. Female and of childbearing potential who does not agree either to remain abstinent or to use effective birth control during the period of the study 13. Intending to become pregnant or breast feeding during the period of the study 14. A history of Guillain-Barré syndrome 15. Receipt of a tetanus or diphtheria vaccination within the 10 years prior to enrolment, as determined from medical review of GP records 16. A previous history of diphtheria or tetanus disease within the last 25 years 17. History of Arthus-type hypersensitivity reaction 18. History of alcohol or substance abuse within the last 5 years. Participants with a positive DOA result at screening may be included at the discretion of the Investigator only if the result is attributable to prescribed or over-the-counter medication or other legitimate use, and there is no evidence of substance abuse or dependency. All decisions must be justified and documented 19. Unable to fulfil all the requirements of the study in the opinion of the Investigator 20. Significant psychiatric history in the last 2 years 21. Presence of permanent body art on both right and left upper arms that would obstruct the ability to observe local reactions at the injection site 22. Any other finding that, in the opinion of the Investigator or Sponsor, deems the subject unsuitable for the study |
| Date of first enrolment | 25/08/2026 |
| Date of final enrolment | 12/01/2027 |
Locations
Countries of recruitment
- United Kingdom
Study participating centre
Southmoor Road
Wythenshawe
Manchester
M23 9QZ
England
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|
Editorial Notes
07/07/2026: ISRCTN received notification of combined HRA/MHRA approval for this trial on 07/07/2026.
08/05/2026: Study's existence confirmed by Health Research Authority (HRA) (UK).
