Kythera Biopharmaceuticals announced that two phase 3 trials investigating its experimental injectable drug, ATX-101, met all primary and secondary endpoints in the reduction of submental fat.
Two identical double blind, randomized trials were conducted at 70 centers in the US and Canada with more than 1,000 patients with moderate to severe submental fat. The efficacy and safety of 2 mg/cm2 ATX-101 vs. placebo were compared for reducing submental fat, which commonly presents as a double chin. The proprietary formulation of a purified synthetic version of deoxycholic acid would be the first-in-class submental contouring injectable drug if approved, Kythera said in a press release.
Five hundred six patients in the REFINE-1 trial and 516 patients in the REFINE-2 trial received up to six treatments approximately 28 days apart. Primary efficacy endpoints were evaluated at 12 weeks after last treatment.
In REFINE-1, 70.3% of ATX-101-treated patients showed improvement of at least one grade from baseline on the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS) and Patient-Reported Submental Fat Rating Scale (PR-SMFRS) compared with 18.7% of placebo patients (P<.001). A simultaneous improvement of at least two grades for both scales was displayed by 13.4% of the ATX-101 cohort compared with 0% of the placebo cohort (P<.001).
In REFINE-2, 66.9% of the ATX-101 treatment arm demonstrated improvement of at least one grade from baseline for both scales compared with 22.4% of the placebo cohort (P<.001). Improvement of at least two grades occurred in 18.7% of the ATX-101cohort and 3.2% of placebo patients (P<.001).
Volume reduction of the submental region as measured by magnetic resonance imaging and improved visual and psychological perception, according to the Patient-Reported Submental Fat Impact Scale (PR-SMFIS), were secondary endpoints. No treatment-related serious adverse events were reported.
“The strong results … are incredibly exciting and consistent with the profile of ATX-101 based on previous data,” Frederick Beddingfield III, MD, PhD, chief medical officer of Kythera Biopharmaceuticals, said in the release. “We look forward to discussing submission plans with US and Canadian regulatory authorities in the near future.”
“An undesirable double chin is often undertreated by aesthetic physicians as there is no proven nonsurgical option to effectively reduce submental fat,” Jean D. Carruthers, MD, FRCSC, FRC, REFINE-1 investigator and clinical professor, department of ophthalmology, University of British Columbia, said in the release. “ATX-101 could … become an important addition to the overall practice of aesthetics.”
Additional study results will be reported at the American Society for Dermatologic Surgery annual meeting Oct. 3-6 in Chicago, according to the release.