Reduction of submental fat continues beyond 28 days after ATX-101 treatment: results from a post-hoc analysis

Reduction of submental fat continues beyond 28 days after ATX-101 treatment: results from a post-hoc analysis

Presenters: Dover JS¹, Shridharani SM², Bloom JD³, Somogyi C⁴, Gallagher CJ⁴

Affiliations: ¹SkinCare Physicians, Chestnut Hill, MA; ²LUXURGERY, New York, NY; ³Main Line Center for Laser Surgery, Ardmore, PA; ⁴Allergan plc, Irvine, CA

Background/Objective: ATX-101 (deoxycholic acid injection) is approved in the United States, Australia, Canada, and Europe for reduction of submental fat (SMF). When injected into subcutaneous fat, ATX-101 results in adipocytolysis, which induces a localized inflammatory response to clear cellular debris and lipids liberated from the injection site. In ATX-101 clinical trials, subjects received 4 to 6 treatments spaced at intervals of 28 ± 5 days. A post-hoc analysis was conducted to characterize the response after a single ATX-101 treatment using data from a patient experience management study (NCT02007434).

Methods: Adults aged 18 to 65 years with a moderate or large amount of SMF (as assessed via the validated 5-point Clinician-Reported and Patient-Reported SMF Rating Scales) who were dissatisfied with the appearance of their face or chin were enrolled. Subjects were randomized to one treatment with either ATX-101 (area-adjusted dose: 2mg/cm²) or placebo. This post-hoc analysis evaluated efficacy among ATX-101-treated subjects (n=68); subjects with moderate SMF at baseline based on clinician assessment (n=49) received 6mL of ATX-101 while subjects with severe SMF (n=19) received 8mL. Outcomes, evaluated at Days 28 and 84 following ATX-101 treatment, included the percentage of subjects who achieved at least a 1-grade improvement in SMF from baseline based on clinician assessment (CR-1 response), percentage of subjects who achieved at least 1-grade improvement in SMF from baseline based on clinician and subject assessment (composite CR-1/PR-1 response), and mean change in SMF thickness from baseline (measured with calipers).

Results: Most ATX-101-treated subjects were female (62%) and Caucasian (79%). At baseline, 72 percent versus 28 percent of subjects had a moderate versus large amount of SMF, respectively. At Day 28, the CR-1 response rate was 14.1 percent. By Day 84, the CR-1 response rate increased to 47.0 percent. Similarly, the composite CR-1/PR-1 response rate was 7.8 percent at Day 28, and increased to 37.9 percent by Day 84. SMF thickness increased from baseline by 2.1mm at Day 28, which might be related to residual swelling and/or induration within the treatment area. However, SMF thickness decreased from baseline by 1.3mm at Day 84.

Conclusion: Results from this analysis demonstrate that reduction of SMF continues in 2 to 3 months following ATX-101 treatment. Overall, these data provide evidence of a progressive reduction in SMF beyond the 28-day retreatment interval used in the pivotal clinical trials and suggest that benefit might be gained by extending the interval between ATX-101 treatments beyond 28 days.

Funding: Funded by Allergan plc.