ATX-101 (deoxycholic acid injection; Kythera Biopharmaceuticals, Inc., Westlake Village, CA [an affiliate of Allergan plc, Dublin, Ireland]) was recently approved for submental fat (SMF) reduction in the United States (Kybella) and Canada (Belkyra). The pivotal trials supporting these approvals revealed that ATX-101 is associated with common injection-site treatment reactions consistent with its mechanism of action and administration procedure.OBJECTIVE
The purpose of this study was to evaluate 4 patient experience management paradigms targeting the common injection-site adverse events of pain, swelling/edema, and bruising after a single treatment session with ATX-101.METHODS
In this double-blind, parallel-group, exploratory Phase 3b study (ClinicalTrials.gov identifier: NCT02007434), subjects with moderate to severe SMF were randomized 4:1 within each paradigm to receive ATX-101 2 mg/cm2 or placebo. In Paradigm 1, subjects received a cold pack application to the treatment area. In Paradigm 2, in addition to cold pack application, subjects were treated with topical lidocaine and injectable lidocaine containing epinephrine. In Paradigm 3, in addition to the interventions of Paradigm 2, subjects received loratadine and ibuprofen. Subjects in Paradigm 4 received the same interventions in Paradigm 3, plus application of a chin strap.RESULTS
Eighty-three subjects were treated. In ATX-101–treated subjects, peak pain occurred within 1 to 5 minutes of treatment, with median values at these time points ranging from 21.4 to 35.7 mm on a 100-mm pain visual analog scale (“mild”). Pain ratings reduced substantially by 15 minutes; at 4 hours after injection, pain was characterized as mild tenderness or mild achiness. Compared with cold alone, treatment with topical and injectable lidocaine reduced median peak pain by 17%. Addition of ibuprofen and loratadine resulted in a total reduction in pain by 40%. Peak swelling/edema in ATX-101–treated subjects was “modest,” with mean values ≤1.7 (on a 0–5 scale) across all paradigms. Swelling/edema was not substantially mitigated by the interventions, including ibuprofen, loratidine, and the use of a chin strap. Bruising associated with ATX-101 treatment was confined to the treatment area, with mean values between 1.0 and 1.4 on a 0-to-5 scale. Bruising was modestly reduced by injectable lidocaine with epinephrine.CONCLUSION
Results from this study support the safety of ATX-101 for SMF reduction, and demonstrate that pain and bruising associated with ATX-101 treatment can be mitigated by a series of simple measures.