Immunogenicity and safety of two respiratory syncytial virus vaccine strategies in lung and allogeneic haematopoietic stem cell transplant recipients: A phase 2 trial RSVaxID

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Hospices Civils De Lyon

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Analytical,Diagnostic,Therapeutic Techniques and Equipment [E]-Surgical Procedures, Operative [E04]

Decision date (initial)

2026-07-06

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

No

Funding sources

DGOS et ANRS (Financement Rech-MIE)

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Safety, Others

To evaluate the RSVpreF-binding antibody response to each of the two RSV vaccine strategies one month after completing vaccination, in two distinct subcohorts which will be separately analyzed: LTR and HSCTR

Secondary objectives 9

1. To assess and compare the RSV-A/RSV-B neutralizing antibody response to each vaccine strategy one month after completing vaccination (In LTR and HSCTR)
2. To characterize and compare the systemic humoral immune response to each vaccine strategy and its persistence up to one year post-vaccination (In LTR and HSCTR)
3. To determine and compare the reactogenicity and safety of each vaccine strategy (In LTR and HSCTR)
4. To determine and compare the mucosal (oral fluid) humoral immune response to each vaccine strategy one month after completing vaccination (In LTR and HSCTR)
5. To analyze the determinants of the humoral immune response to each vaccine strategy (In LTR and HSCTR)
6. To describe medically attended RSV infection episodes in vaccinated participants (In LTR and HSCTR)
7. To characterize RSV isolates from medically attended RSV infection episodes occurring in vaccinated participants (In LTR and HSCTR)
8. To characterize the systemic and mucosal humoral immune response to each vaccine strategy at the time of medically attended RSV infection episodes occurring in vaccinated participants (In LTR and HSCTR)
9. To compare the systemic and mucosal humoral immune response to each vaccine strategy in participants with medically attended RSV infection episodes and in matched participants (matching criteria: age, time from transplantation, type of transplantation [LTR or HSCTR], type of vaccine strategy) without medically attended RSV infection episodes

Conditions and MedDRA coding

allogeneic haematopoietic stem cell transplant recipient

Study design 1 period

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 4

1. Prior lung transplantation (including combined transplants) performed ≥3 months before the first vaccine administration (LTR) OR prior allogeneic haematopoietic stem cell transplantation performed within ≥3 months to 5 years before the first vaccine administration (HSCTR)
2. active follow-up at one of the study centres
3. age ≥18 years at inclusion
4. providing written, informed consent

Exclusion criteria 19

1. Previous vaccination with any licensed or investigational RSV vaccine
2. any vaccine administration within two weeks before inclusion or planned receipt within two weeks following each experimental vaccine administration
3. known bleeding disorder which, in the opinion of the investigator, contraindicates intramuscular injection
4. any female participant who is pregnant, lactating or planning to become pregnant during the study period. Female participants of childbearing potential may be enrolled if they have a negative pregnancy test on the day of each vaccine administration and must agree to continue adequate contraception during 12 weeks; (Contraception is considered effective when it consists of one of the following: use of a male condom during all sexual activity and/or efficient oral hormonal contraception (better considered combined contraception) and/or an intrauterine device and/or hormone-releasing intrauterine system and/or history of bilateral tubal ligation and/or history of vasectomy, provided the male partner is the trial participant's only sexual partner and/or sexual abstinence)
5. expected unavailability for the planned study visits
6. concurrent participation in another active clinical study at the time of inclusion which includes the application of investigational products (medication, vaccine) or an interventional research using an invasive medical device during the study period
7. acute, severe febrile illness at the time of inclusion
8. any person deprived of liberty by a judicial or administrative decision
9. any person under legal protection measures
10. any person non affiliated to National French social security system or equivalent
11. History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccines
12. Active malignant disease at inclusion (with the exclusion of non-melanoma skin cancer)
13. Receipt of immunoglobulins and/or any plasma derivatives during the period starting 90 days before the first study vaccine administration, or planned administration during the study period
14. Acute cellular graft rejection episode treated by corticosteroid boli within one month before first vaccine administration (LTR)
15. ongoing plasmapheresis for acute humoral graft rejection (LTR)
16. ongoing, acute graft-versus-host disease of grade II/III/IV (HSCTR)
17. Chronic graft-versus-host disease which is not stable for at least one month prior to first vaccine administration (HSCTR)
18. anti-CD20 and/or anti-CD52 therapy within the last 6 months
19. administration of anti-thymocyte globulin within the last 3 months;

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Proportion of participants in each group who achieve a seroresponse one month after completion of vaccination (V2). A seroresponse is defined as either (1) seroconversion or (2) a ≥4-fold rise in RSVpreF-binding serum IgG concentration from baseline, as measured by enzyme immunoassay (EIA).

Secondary endpoints 9

1. RSV-A and RSV-B serum 50% neutralizing geometric mean titres (GMT) and corresponding neutralizing titre geometric mean fold rises (GMFR), measured by an RSV neutralization assay [time frame: baseline (visit 1), one month after completing vaccination (V2)].
2. Geometric mean concentrations (GMC) and corresponding geometric mean fold rises (GMFR) of RSVpreF-binding serum IgG, measured by standard EIA; proportion of participants in each group achieving a ≥2-fold rise in RSVpreF-binding serum IgG between baseline and visit 2, as measured by standard EIA; Log (serum dilution) for 50% signal inhibition in D25- and palivizumab-competitive EIA [time frame: baseline, pre-dose-2 (only arm B, visit 1b), v2 and one-year after first vaccine dose (v3)
3. Descriptive: frequency, type and severity of local and systemic solicited adverse events within 7 days following each vaccine administration; frequency, type and severity of unsolicited adverse events within 30 days following each vaccine administration; severe adverse events and adverse events of special interest until the end of study
4. Geometric mean titres (GMT) and corresponding geometric mean fold rises (GMFR) of RSVpreF-binding oral fluid IgA, measured by EIA in oral fluid [time frame: baseline, visit 2]
5. Analysis of determinants of humoral immunogenicity: [Time frame: baseline, V1b, V2, V3] age, time from transplantation, acute rejection episode(s) before and during the study period, type of induction immunosuppression, ongoing immunosuppressive treatment at the time of vaccination (in LTR); age, time from transplantation, stem cell source, type of donor, acute/chronic GVHD before and during the study period, ongoing immunosuppressive treatment at the time of vaccination (in HSCTR)
6. Descriptive: frequency and severity (overall survival, need for hospitalization, ICU hospitalization, type of treatment, respiratory deterioration [in LTR only] until the end of study) of RT-PCR confirmed, medically attended RSV infection episodes
7. Full-length genome sequencing and sequence analysis of any clinical RSV isolate
8. Geometric mean concentrations (GMC) of RSVpreF-binding serum IgG, geometric mean titres (GMT) of RSV-A/RSV-B serum neutralizing antibodies (NAbs) and GMT of RSVpreF-binding oral fluid IgA in vaccinated participants with medically attended RSV infection [Time frame: at the time of medically attended RSV infection]
9. Geometric mean concentrations (GMC) of RSVpreF-binding serum IgG, geometric mean titres (GMT) of RSV-A/RSV-B serum neutralizing antibodies (NAbs) and GMT of RSVpreF-binding oral fluid IgA in participants with medically attended RSV infection and matched participants without medically attended RSV infection episodes [Time frame: baseline, visit 2]

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 2

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Hospices Civils De Lyon

Sponsor organisation

Hospices Civils De Lyon

Address

3 Quai Des Celestins, Bp 2251 Bp 2251

City

Lyon Cedex 02

Postcode

69229

Country

France

Scientific contact point

Organisation

Hospices Civils De Lyon

Contact name

CONRAD Anne

Public contact point

Organisation

Hospices Civils De Lyon

Contact name

CONRAD Anne

Locations

1 EU/EEA country · 16 investigational sites

By country

Investigational sites

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 12 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

1 submissions — initial application plus substantial / non-substantial modifications