Study to Evaluate Safety, Efficacy and Immunogenicity of Acne mRNA Vaccine in Adults With Moderate to Severe Acne

The purpose of the trial is to evaluate the safety, efficacy and immunogenicity of up to 3 intramuscular injections of the Acne mRNA vaccine candidate at up to three dose levels in adult participants aged 18 to 45 years with moderate to severe acne.

Acne vulgaris (acne) is a highly prevalent inflammatory skin disease, especially in adolescents and young adults. Acne is estimated to affect 231 million people worldwide, therefore being one of the most prevalent diseases globally. Acne is also one of the top causes of years lived with disability and nonfatal disease burden. Despite being one of the most prevalent diseases worldwide, the mainstays of acne treatment have remained largely unchanged over the past 30 years. To date there is still no safe and effective treatment that can prevent and cure this disease.

The aim of this first-in-human (FIH), Phase I/II trial is to evaluate the safety, efficacy and immunogenicity of the Acne mRNA vaccine candidate at three different dose levels in adults aged 18 to 45 years with moderate to severe acne. The results of this FIH and proof of concept study will allow selection of the vaccine dose level to be used in Phase III pivotal efficacy trial(s) and to generate preliminary data to further select the vaccine regimen.

Eligibility Criteria:
Inclusion Criteria:

* Participants who are overtly healthy as determined by medical evaluation including medical history, physical examination, and laboratory tests as judged by the investigator
* Clinical diagnosis of moderate or severe facial acne vulgaris with Investigator's Global Assessment (IGA) score of Moderate or Severe (grade 3 or grade 4 on the 5-grade IGA scale) and ≥ 25 non-inflammatory lesions (ie, open and closed comedones) and ≥ 20 inflammatory lesions (ie, papules and pustules) and ≤ 2 nodulocystic lesions (ie, nodules and cysts)

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

* Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within 6 months prior to the first study intervention administration; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
* Known systemic hypersensitivity to any of the study intervention components (eg, polyethylene glycol \[PEG\], polysorbate); history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances; any allergic reaction (eg, anaphylaxis) after administration of mRNA coronavirus disease 2019 (COVID-19) vaccine
* Active nodulocystic acne, acne conglobate, acne fulminans, secondary acne (eg, chloracne, drug-induced acne) or other forms of acne (eg, acne mechanica)
* Use of any acne-affecting treatment without an appropriate washout period
* Receipt of any vaccine (other than the study vaccine) in the 4 weeks preceding any study intervention administration or planned receipt of any vaccine (other than the study vaccine) in the 4 weeks following any study intervention administration
* Previous vaccination against C. acnes with an investigational vaccine
* Receipt of immune globulins, blood or blood-derived products in the past 3 months
* Self-reported or documented seropositivity for human immunodeficiency virus (HIV), hepatitis B virus, or hepatitis C virus.

The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.