ATX-101 for the reduction of double chin caused by submental fat: Results from the ATX-101-10-16 European phase III study

Background: ATX-101, a proprietary formulation of synthetically derived sodium deoxycholate (salt of deoxycholic acid), is an investigational facial injectable treatment for the reduction of double chin. Double chin is the result of submental fat, and when associated with a predisposition or aging is often unresponsive to diet and exercise. Methods: In this first of 2 pivotal phase III, multicenter, double-blind, placebo-controlled studies, 363 subjects with submental fat rated as moderate or severe were randomly assigned (1:1:1) to receive injections of ATX-101 dosed at 1 mg/cm2 or 2 mg/cm2, or placebo (vehicle). Subjects received up to 4 treatment sessions, spaced at least 28 days apart, and were followed until 12 weeks after their last treatment. Clinicians evaluated submental fat using the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS). Subjects evaluated the amount of their submental fat using the Patient-Reported Submental Fat Rating Scale (PR-SMFRS), the satisfaction with their appearance associated with the face and chin using the Subject Self-Rating Scale (SSRS), and the psychological and visual impact of their submental fat using the Patient-Reported Submental Fat Impact Scale (PR-SMFIS). Satisfaction with treatment was measured using the Global Post-Treatment Satisfaction Scale. Results: At 12 weeks after last treatment, both 1 mg/cm2 and 2 mg/cm2 ATX-101 groups showed a statistically significant greater improvement (P<.001) compared to placebo in mean scores for CR-SMFRS (0.7 and 0.9, respectively, vs 0.2 with placebo), PR-SMFRS (0.8 and 1.0 vs 0.3), and SSRS (2.4 and 2.8 vs 1.4), and psychological and visual impact. Both ATX-101 groups also showed greater satisfaction with treatment compared to placebo (P <.001). The incidence of treatment satisfaction was 79% and 91% compared to 40%. Adverse events related to ATX-101 were mostly mild to moderate in severity, transient, and limited to the injection site. The most common were pain, swelling, numbness, erythema, and induration. Conclusion: ATX-101 treatment was associated with a reduction in submental fat and in its psychological and visual impact, and an improvement in subject satisfaction with appearance and with treatment. These changes were statistically significant compared to placebo. These results confirm those from the second phase III European study and offer evidence that ATX-101 may offer a new pharmacologic option for reducing double chin and improving facial appearance. Supported by Kythera Biopharmaceuticals, Inc.