A Phase 1 Study to Evaluate JCXH-108, an mRNA-based Vaccine Against RSV

April 21, 2026 updated by: Immorna Biotherapeutics, Inc.

A Phase 1 Randomized, Double-Blinded Study to Assess the Safety, Reactogenicity and Immunogenicity of JCXH-108, an mRNA-based Investigational Vaccine Against Respiratory Syncytial Virus (RSV) in Healthy Subjects ≥ 60 Years of Age and 18-45 Years of Age

The goal of this clinical trial is to assess the safety, reactogenicity and immunogenicity of an mRNA-based vaccine, JCXH-108, the prevention of Respiratory Syncytial Virus (RSV) infection and diseases.

Participants will be randomized to receive either JCXH-108 or placebo.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

This Phase 1 study plans to enroll a total of 75 participants.

Three cohorts with two different dose levels will be explored and each cohort will enroll 25 participants. Participants in each cohort will be randomized (4:1) to receive either JCXH-108 (n=20) or placebo (normal saline, n=5). A low dose of JCXH-108 will be explored vs placebo in the 18-45 years of age group first. A high dose will be explored vs placebo in the 18-45 years and ≥ 60 years of age groups once safety data is reviewed for the Sentinel subjects in the low dose cohort. The dose level of JCXH-108 will depend on the time the participant joins the study. Each participant will receive a single dose of JCXH-108 administered intramuscularly (IM) on day 1.

Study Type

Interventional

Enrollment (Actual)

75

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Florida
      • Jupiter, Florida, United States, 33458
        • Health Awareness
    • Louisiana
      • New Orleans, Louisiana, United States, 70115
        • DelRicht - New Orleans
    • Missouri
      • St Louis, Missouri, United States, 63131
        • Sundance Clinical Research

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Main Inclusion Criteria:

  • Sex: Male or female; female subjects may be of childbearing potential or postmenopausal.
  • Age: 18-45 years of age or ≥ 60 years of age at screening
  • Status: Healthy subjects.
  • Subjects must agree to not be vaccinated with any RSV vaccine while participating in this study.
  • Subjects must agree to not be vaccinated with any RNA-based vaccines 30 days before D1 through 30 days after D1.

Main Exclusion Criteria:

  • Subjects with current diagnosis of RSV infection or diseases.
  • Previous vaccination against RSV.
  • Subjects with any respiratory illness deemed clinically relevant by the Investigator within the past month OR hospitalization >24 hours for any reason within the past month prior to Day 1.
  • Subjects with history of myocarditis or pericarditis, or with adverse events (AEs) after mRNA vaccination that are in nature and severity beyond the common expected AEs necessitating medical intervention.
  • Subjects who received any non-live vaccine within 14 days prior to Day 1.
  • Subjects who received within 28 days prior to Day 1: (1) Any live vaccine, (2) Immunomodulators or immune-suppressive medication, (3) Granulocyte or granulocyte-macrophage colony-stimulating factor, and (4) Three or more consecutive days of systemic corticosteroids. Note: subjects on stable dose of steroid replacement (for chronic disease such as iatrogenic deficiency) of prednisone ≤10 mg/day or equivalent are allowed.
  • Subjects who currently receive other investigational agents or devices.
  • Subjects with active or suspected immunosuppression, immunodeficiency, asplenia, recurrent severe infections or autoimmune diseases. Certain immune-mediated conditions (e.g., Hashimoto thyroiditis) that are well controlled and stable are allowed.
  • Subjects receiving systemic antiviral therapy.
  • Subjects with a positive screening test for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies, or anti-human HIV-1 and 2 antibodies, syphilis.
  • Subjects with a positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at Screening or on Day 1 prior to vaccine administration (JCXH-108 or placebo).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Investigational product
Subjects randomized to this arm will be given the investigational product (JCXH-108).
Biological: JCXH-108
IM injection
Placebo Comparator: Placebo
Subjects randomized to this arm will be given a placebo.
Other: Placebo
IM injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
SAE Frequency
Time Frame: Day 1 - Day 180 (6 Months)
Frequency of SAEs characterized by type, severity, duration, and relationship to the JCXH-108 recorded from Day 1 (D1) post-vaccine administration through follow-up completion.
Day 1 - Day 180 (6 Months)
Injection site reaction
Time Frame: Day 1 - Day 30
Solicited local injection site reactions characterized by frequency, severity, and duration recorded within 30 days after administration after vaccine administration (JCXH-108 or Placebo)
Day 1 - Day 30
Solicited systemic reaction frequency
Time Frame: Day 1 - Day 30
Solicited systemic adverse reactions characterized by frequency, severity, and duration recorded within 30 days after vaccine administration (JCXH-108 or Placebo)
Day 1 - Day 30
AE frequency
Time Frame: Day 1 -Day 30
Adverse events (AEs) including unsolicited AEs characterized by type, severity, duration, and relationship to the vaccine (JCXH-108 or Placebo) recorded from Day 1 post-vaccine administration to within 30 days following vaccine administration
Day 1 -Day 30
Medically attended AE frequency
Time Frame: Day 1 - Day 180 (6 Months)
Medically attended AEs (MAAEs) characterized by frequency, severity, duration, and relationship to the vaccine (JCXH-108 or Placebo) recorded from Day 1 post-vaccine administration (JCXH-108 or Placebo) through follow-up completion
Day 1 - Day 180 (6 Months)
Potential immune-mediated adverse events frequency
Time Frame: Day 1 - Day 180 (6 Months)
Potential immune-mediated disease (pIMDs) characterized by frequency, severity, duration, and relationship to the vaccine (JCXH-108 or Placebo) recorded from Day 1 post-vaccine administration (JCXH-108 or Placebo) through follow-up completion
Day 1 - Day 180 (6 Months)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
RSV-A and RSV-B antibody levels
Time Frame: Day 1 - Day 180 (6 Months)
Levels of serum neutralizing antibodies against RSV-A and RSV-B as compared to Day 1 pre-dose (baseline) at Day 29, Month 3 and Month 6 after the vaccine administration
Day 1 - Day 180 (6 Months)
IgG antibody levels
Time Frame: Day 1 - Day 30
Levels of serum RSV pre-F antibodies of IgG1, IgG2, IgG3, and IgG4 as compared to Day 1 pre-dose (baseline) at Day 29, after the vaccine administration. Measured in women of childbearing potential only.
Day 1 - Day 30

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
T-cell responses
Time Frame: Day 1 -Day 180 (6 Months)
T-cell responses to vaccine-encoded antigen in peripheral blood mononuclear cells (PBMCs) determined by enzyme-linked immunosorbent spot (ELISpot) and Intracellular Cytokine Staining (ICS) assays, as compared to baseline (Day 1 pre-dose) at 29 days and 6 months after the vaccine administration (Day 30 and Month 6).
Day 1 -Day 180 (6 Months)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Immorna Biotherapeutics, Inc.

Collaborators

Tigermed Consulting Co., Ltd

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 25, 2024

Primary Completion (Estimated)

June 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

August 19, 2024

First Submitted That Met QC Criteria

August 19, 2024

First Posted (Actual)

August 21, 2024

Study Record Updates

Last Update Posted (Actual)

April 23, 2026

Last Update Submitted That Met QC Criteria

April 21, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • JCXH-108-001

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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