a phase 1 study to evaluate jcxh-108, an mrna-based vaccine against rsv

Conditions: Respiratory Syncytial Virus (RSV); Infectious Disease

Summary: 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.

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.

Eligibility criteria:
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).

Keywords: mrna vaccine rsv vaccination healthy subjects