Kythera Biopharmaceuticals has commenced two pivotal US Phase III trials of its ATX-101, an injectable drug under clinical investigation for the reduction of fat under the chin, known as submental fat.
ATX-101 is a proprietary formulation of sodium deoxycholate that reduces subcutaneous fat through localised fat cell membrane disruption followed by elimination from the treated area.
The two Phase III multi-centre randomised double-blind prospective placebo-controlled trials, known as Randomized Double-blind Evaluation of Submental Fat Reduction In ATX-101 Treated Patients-1 (REFINE-1) and REFINE-2, will enrol a total of 1,000 patients in around 70 centres across the US and Canada.
Both trials are intended to evaluate the efficacy, safety and tolerability of ATX-101 (2mg/cm²) subcutaneous injections versus placebo for the reduction of localised subcutaneous fat in the submental area, as measured from baseline to 12 weeks after final treatment.
Kythera Biopharmaceuticals chief medical officer Patricia Walker said the design for the REFINE trials is based on multiple prior pre-clinical and clinical trials, which to date have shown encouraging efficacy and safety data for ATX-101.
"We hope these Phase III trials, as part of our continued clinical investigation of ATX-101, will ultimately lead to a safe, effective and well-studied treatment for the reduction of unwanted submental fat," Walker added.
The efficacy of ATX-101 is measured using two independent scales, the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS) and the Patient-Reported Submental Fat Rating Scale (PR-SMFRS)
Kythera president and CEO Keith Leonard said: "The initiation of our pivotal REFINE-1 and REFINE-2 clinical trials marks meaningful progress as we continue to assess the efficacy and safety of ATX-101 as a non-surgical alternative for localized fat reduction."
The preliminary results from the first two years of an ongoing five-year, non-treatment follow-up study demonstrated that more than 90% of patients enrolled in the long-term study maintained or improved their response.
The findings from the two Phase III trials are likely to be reported in the first half of this year.