The purpose of this study is to assess safety, reactogenicity, and immune response of the candidate UTI vaccine compared to placebo in adults between and including 18-64 years of age (YOA), and to perform a preliminary evaluation of clinical efficacy in females between and including 18-64 YOA.

This clinical trial consists of 2 parts. Part 1 will consist of antigen dose-escalation (start with least dose with gradual increase in dose) Safety Lead-In (SLI) in healthy participants. Part 2 (Proof of Principle [PoP]) will start after the safety review of all safety data in Part 1 and will consist of participants with history of at least 1 episode of urine culture confirmed E. coli UTI in the last 12 months prior to the study intervention administration.

Inclusion Criteria:

• Participants, who, in the opinion of the investigator, can and will comply with the requirements of the protocol.

• Written informed consent obtained from the participant prior to performance of any study-specific procedure.

• Female participants of non-childbearing potential may be enrolled in the clinical study.

• Female participants of childbearing potential may be enrolled in the clinical study, if the participant:

  • has practiced adequate contraception for 1 month prior to study intervention administration, and
  • has a negative pregnancy test on the day of study intervention administration, and
  • has agreed to continue adequate contraception during the entire treatment period and for at least 1 month after completion of the study intervention administration series.

• Blood sample for simultaneous follicle stimulating hormone (FSH) and estradiol levels may be collected.

Additional inclusion criterion only for participants in Part 1 of the study (SLI):

• Female and male between and including 18 through 64 YOA at the time of ICF signature.
• Healthy participants, according to medical history, laboratory assessment and clinical examination at Screening Visit.

Additional inclusion criterion only for participants in Part 2 of the study (PoP):

• Females between and including 18 through 64 YOA at the time of ICF signature.
• Female participants with documented history of at least 1 episode of urine culture confirmed E. coli uncomplicated UTI in the last 12 months prior to study vaccine administration.

Exclusion Criteria:

Medical conditions:

• History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention(s).
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination.
• Hypersensitivity to latex.
• History of pIMD.
• Acute or chronic clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests.
• History of endocrinologic, hematologic, metabolic, urologic, dermatologic, or gastrointestinal conditions that, in the opinion of the investigator, places the participant at unacceptable risk or would make adhering to study procedures for the duration of the study difficult.
• Recurrent history or uncontrolled neurological disorders or any neuroinflammatory (including, but not limited to demyelinating disorders, encephalitis or myelitis of any origin), congenital neurological conditions, encephalopathies, or seizures.
• Any behavioral or cognitive impairment or psychiatric disease that, in the opinion of the investigator, may interfere with the participant's ability to participate in the study.
• Condition that in the judgment of the investigator would make intramuscular injection unsafe.
• Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.

Additional exclusionary medical conditions only for participants in Part 1 of the study (SLI):

• Any clinically significant hematologic and/or biochemical laboratory abnormality at Screening Visit.

Additional exclusionary medical conditions only for participants in Part 2 of the study (PoP):

• The participant has UTI that is known or suspected to be due to fungal, parasitic, or viral pathogens; or known or suspected to be due to Pseudomonas aeruginosa or any Enterobacter species.

• The participant has symptoms known or suspected to be caused by another disease process, such as asymptomatic bacteriuria, overactive bladder, chronic incontinence, or chronic interstitial cystitis, that may interfere with the clinical efficacy assessments.

• The participant has an anatomical or physiological anomaly that predisposes the participant to UTIs or may be a source of persistent bacterial colonization, including calculi, obstruction or stricture of the urinary tract, primary renal disease or neurogenic bladder, or the participant has a history of anatomical or functional abnormalities of the urinary tract.

• The participant has an indwelling catheter, nephrostomy, ureteral stent, or other foreign material in the urinary tract.

• The participant who, in the opinion of the investigator, has an otherwise complicated UTI or has an active upper UTI.

• Use of any investigational or non-registered product (drug, vaccine or invasive medical device) other than the study intervention(s) during the period beginning 30 days before the first dose of study intervention(s) (Day -29 to Day 1), or their planned use during the study period.

• Previous administration of a vaccine or immunostimulant targeting rUTI.

• Participants currently on a prophylactic agent for rUTI (including antibiotics, methenamine, D-mannose).

• Planned administration and/or administration of a vaccine not foreseen by the study protocol in the period starting 15 days before the first dose and ending 15 days after the last dose of study intervention(s) administration.

• Administration of immunoglobulins and/or any blood products or plasma derivatives during the period starting 90 days before the study intervention or planned administration during the study period.

• Chronic administration of immune-modifying drugs (defined as more than 14 consecutive days in total) and/or planned use of long-acting immune modifying treatments at any time up to the end of the study.

  • Up to 3 months prior to the study intervention administration:
  • For corticosteroids, this will mean prednisone equivalent >=20 mg/day for adult participants. Inhaled and topical steroids are allowed.
  • Up to 3 months prior to study intervention administration: long-acting immune-modifying drugs including among others immunotherapy (e.g., TNF-inhibitors), monoclonal antibodies, antitumoral medication.

• Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention (drug, vaccine or invasive medical device).

• Pregnant or lactating female participant.

• Female participant planning to become pregnant or planning to discontinue contraceptive precautions before 1 month after completion of the study intervention administration series.

• History of chronic alcohol consumption and/or drug abuse, based on investigator judgment.

• Persons under guardianship or trusteeship.

• Persons deprived of liberty.

• Any study personnel or their immediate dependents, family, or household members.

Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/About\_GSK\_Patient\_Level\_Data\_Sharing\_Final\_13July2023.pdf

Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or terminated asset(s) across all indications.

Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension may be granted, when justified, for up to 6 months.

Data will be collected in an observer-blind manner