KYTHERA presents long-term results from ATX-101 Phase 2 study at ASDS 2011

Nov 7 2011

KYTHERA Biopharmaceuticals, Inc. ("KYTHERA"), a privately-held biotechnology company focused on the development and commercialization of prescription products in aesthetic medicine, presented results from a long-term follow up study assessing persistence of efficacy and post-treatment safety of ATX-101, a first-in-class, injectable drug that is under investigation for the reduction of submental ('under the chin') fat. Kevin C. Smith, MD, FAAD, FRCPC presented study results from the first two years of a 5-year follow up on Phase 2A patients at the 2011 Annual Meeting of the American Society for Dermatologic Surgery (ASDS) in Washington, DC.

As of mid-2011, 45 responders, defined as ATX-101 treated subjects who exhibited a ≥1-point improvement based on physician assessment (CR-SMFRS) at the completion of Phase 2A studies, have enrolled in the long-term follow-up study. Preliminary results demonstrate that at a 2-year follow up visit, >90% of these subjects sustained or improved their response based on physician evaluation using the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS). Additionally, 80% of these subjects demonstrated sustained or improved satisfaction based on patient evaluation using the Subject Satisfaction Rating Scale (SSRS). No new adverse events were reported during the 2-year follow up evaluation period.

"These results from such a rigorously controlled study are encouraging as they address key questions in terms of long-term safety and durability of the aesthetic correction with ATX-101," said Kevin C. Smith, a board-certified dermatologist in private practice in Niagara Falls, Ontario, Canada and an investigator in the Phase 2A and long-term follow up studies. "Treatment results with ATX-101 appear to be sustained and well-tolerated, which illustrates its potential as a novel, non-surgical approach to reducing submental fat."

Results from two randomized, double-blind, placebo-controlled, dose-ranging Phase 2A studies were originally presented at the Scientific Session during the 2009 American Society for Dermatologic Surgery (ASDS) and American Society of Cosmetic Dermatology and Aesthetic Surgery (ASCDAS) Joint Annual Meeting. In both studies, clinical response was evaluated by physician assessment using a validated, 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS) and by subject assessment using a 7-point Subject Satisfaction Rating Scale (SSRS). Results demonstrated that ATX-101 was well tolerated and the most common adverse events were mild pain, swelling, numbness, bruising and induration. Additionally, ATX-101 yielded statistically significant reductions on both physician and subject assessments versus placebo in all dose groups (baseline to week 16, p<0.05).

Subjects who completed participation in the Phase 2A studies were eligible to enroll in a long-term follow-up study allowing evaluation of safety and efficacy measures for up to 5 years. Efficacy measures include physician and subject assessment using CR-SMFRS and SSRS, respectively.

"While these results are still preliminary, they support our expectation that ATX-101 may result in a long-term aesthetic correction," said Patricia Walker, MD, PhD, KYTHERA's Chief Medical Officer. "We look forward to continuing to follow these patients and to further characterizing the long-term safety and efficacy profile of ATX-101."

A poster highlighting results from a Phase 2B study with ATX-101 using investigator, subject and magnetic resonance imaging assessments was also presented by Jeffrey S. Dover, MD, FRCPC, a board-certified dermatologist in private practice in Chestnut Hill, MA and an investigator in the ATX-101 Phase 2B study.

KYTHERA has completed extensive development work on ATX-101 for the reduction of submental fat, completing seven clinical trials in more than 350 subjects. European Phase 3 studies of ATX-101 were initiated in late 2010 (with completed enrollment of more than 700 subjects) in collaboration with Bayer's Dermatology unit, which has licensed rights to ATX-101 outside of the U.S. and Canada.