A multi-centre, double-blind, randomized, parallel group, placebo controlled efficacy and safety study of oral CTX-4430 for the treatment of moderate to severe facial acne vulgaris.

Inclusion Criteria:

1. Must provide Informed consent.
2. Male or female aged 16 to 44 inclusive.
3. Moderate to severe facial acne vulgaris as defined in the protocol.

Exclusion Criteria:

1. Positive testing for HIV, HBsAg, or hepatitis C virus (HCV).
2. Females who are pregnant, lactating, or planning to become pregnant during the study.
3. Any systemic medical condition which, in the opinion of the investigator, would put the participant at risk by participation in the study.
4. Any systemic or dermatologic disorder that, in the opinion of the investigator will interfere with the assessment of the study endpoints (e.g. psoriasis).
5. Concurrent or previous use of an investigational drug or device within 30 days prior to screening.
6. The presence of acne conglobata, acne fulminans, secondary acne, or nodulocystic acne.
7. The presence of known or suspicious unresolved dermatological cancerous or pre-cancerous lesions.
8. Hypersensitivity or idiosyncratic reaction to compounds related to CTX-4430 or any of its components.