The purpose of this study is to assess the safety profile of intramuscular injections of the Acne mRNA vaccine at 3 dose levels compared with placebo in 12 to 17 years old participants with moderate to severe acne.
An early safety data review (ESDR) will be conducted after each subcohort has completed an injection round; enrollment of the next higher dose level subcohort or progression of a subcohort to the subsequent injection round will only proceed if no safety concerns are identified. This sequential process will allow a cautious approach to vaccine injection in the adolescent population.
Study details are as follows:
* Before being enrolled in the study, participants complete a 4-week (ie, 1-month) screening period during which they will be called over the telephone approximately in the middle of the screening period to check they are not using prohibited medications and to remind them about the facial hygiene requirements. * Once the screening period has been completed, the study duration will be up to 13 months for each participant * Participants will be invited to a long-term extension study through a separate protocol.
Aged 12 to 17 years on the day of the first study intervention administration
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)
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 study intervention components or history of life-threatening reaction to study intervention(s) or products with the same substances
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 wash-out period
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Treatment groupsSee each treatment group below.