KYTHERA BIOPHARMACEUTICALS INITIATES PHASE II STUDY OF ITS ADIPOLYTIC AGENT FOR REDUCTION OF SUBMENTAL FAT

Kythera Biopharmaceuticals Initiates Phase II Study of Its Adipolytic Agent for Reduction of Submental Fat

LOS ANGELES -- Kythera Biopharmaceuticals, Inc. (“Kythera”) announced today that it has initiated a Phase II study of its proprietary product, ATX-101, for the reduction of unwanted submental (under chin) fat. This is the first in a series of planned studies of ATX-101 in aesthetic applications aimed at proving the product’s safety and effectiveness as a “liposculpting” agent.

This is also the first prospective, placebo-controlled, study on an adipolytic agent under an active registration program. The study is designed as part of a package aimed at achieving registration of ATX-101 as an approved prescription drug in the U.S., Europe and Asia. The Phase II multi-national, randomized, double-blind, placebo-controlled, study will enroll 72 patients and assess safety, tolerability and efficacy across three concentrations of ATX-101 in reducing small volumes of submental fat. The study will assess multiple physician and patient measured endpoints and is being conducted at centers in the United Kingdom and Australia.

“We hope ATX-101 will ultimately provide a safe, effective, and well-characterized treatment for the cosmetic reduction of small volumes of fat,” said Patricia Walker, MD, PhD, Kythera’s Chief Medical Officer. “Today, many individuals who are not otherwise overweight seek treatment to reduce undesired fat in spot areas; unfortunately some opt for unproven treatments, often delivered through inconsistent procedures with no or poorly characterized safety and effectiveness profiles. This trial and development program are important and positive steps toward providing these individuals with a safe and clinically proven treatment for localized fat reduction.”

ATX-101 is currently completing a multi-dose, dose-escalating, Phase I/II safety and pharmacokinetic study under a U.S. IND for the treatment of superficial lipomas. “We are very pleased with the safety results seen to date,” said Walker.

“The initiation of the ATX-101 submental fat trial is another important milestone for Kythera and for individuals who seek less-invasive options for reduction in small volumes of unwanted fat,” said Keith Leonard, Kythera’s President and CEO. “There has been explosive growth in use of injectable adipolytic agents, yet none have been studied in well-controlled trials or subjected to the rigorous review process required by public health regulators. This has led to these treatments being banned in several countries around the world. Kythera is committed to bringing patients products with proven safety and efficacy and is investing the time, money and effort required to bring safe, effective, well characterized, and approved products to market.”

Kythera established its adipolytic agent program through a broad licensing agreement with Los Angeles Biomedical Institute at Harbor-UCLA Medical Center in 2005. Under the terms of the agreement, Kythera obtained the exclusive rights to develop, manufacture and commercialize the ATX-101 compound for all applications in all markets, worldwide.

About Kythera Biopharmaceuticals

Kythera is a privately held biopharmaceutical company focused on science and innovation in aesthetic and restorative dermatology. These markets are expanding rapidly driven by an aging population, increasing discretionary income, and an evolution of patient preference toward restorative and preventative care. The company uses the tools of biotechnology to develop prescription therapeutics for these emerging markets. Kythera has active or exploratory programs in adipolysis, photoaging and dermal contouring and topical neuromodulation.

For more information about Kythera, please visit the company’s Web site at www.kytherabiopharma.com.