An Integrated Phase 1a/1b, First-in-human, Randomized, Double-blinded, Placebo-controlled Split-scar Study in a Cohort of Adult Participants with Hypertrophic Sternotomy Scars to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics

Exclusion Criteria15

• Clinically significant gastrointestinal, renal, hepatic, neurologic, hematologic, endocrine, oncologic, pulmonary, immunologic, psychiatric, or skin disease or any other condition, that, in the opinion of the Investigator, would jeopardise the safety of the participant or impact the validity of the study results;
• Current acute skin condition (e.g. eczema, psoriasis, broken skin, wounds) or large tattoos, scars (with exception of sternotomy scar for Part 2) or excess hair at the study product application site. Normal hair coverage and small blemishes are acceptable at the discretion of the Investigator;
• History of keloid scarring or hypertrophic scarring (except for Part 2);
• History of immediate hypersensitivity to any medication or currently suffers from clinically significant systemic allergic disease;
• Has received or is anticipated to receive any prescription systemic or topical medication within 14 days or 5 half-lives, whichever is longer, prior to commencement of study product, or use of any over-the-counter, complementary, or alternative medicine within 48 hours prior to commencement of study product. Note: paracetamol up to 2 grams per day, intranasal and inhaled corticosteroids, killed and inactive vaccines, contraceptives, antihistamines, vitamins, and dietary supplements are permitted. Topically administered treatments may be permitted at Investigator discretion and if not applied within the treatment zone of SNT-9465/placebo;
• Positive screening test for hepatitis panel (HBsAg, anti-HCV) or human immunodeficiency virus (HIV). Positive anti-HCV antibody is allowed if HCV PCR is negative;
• History of drug abuse in the 2 years prior to screening;
• Receipt of blood donation, or loss or donation of blood greater or equal to 450 mL, within 30 days prior to commencement of study product, or plasma donation within 14 days before commencement of study product;
• Has received an experimental therapy within 30 days or 5 half-lives, whichever is longer, prior to commencement of study product;
• Systemic infection, other than the common cold, in the 7 days prior to commencement of study product.
• Active skin infection or inflammatory condition within or adjacent to the scar treatment area;
• Prior treatment to the target scar within 3 months (e.g., corticosteroids, laser therapy, cryotherapy, radiotherapy, surgical revision);
• Use of systemic anti-fibrotic agents, immunosuppressants, or medications affecting collagen metabolism (e.g., methotrexate, cyclosporine) within 3 months of screening;
• Uncontrolled diabetes (HbA1c greater or equal 8%) or current smoking, which may impair scar remodelling;
• Recent cardiac events (e.g. myocardial infarction or unstable angina within 6 months of screening).