Damian McNamara

March 14, 2013

MIAMI BEACH, Florida — Deoxycholic acid (ATX-101, Kythera Biopharmaceuticals) improves the appearance of unwanted fat under the chin, results of an open-label phase 3 clinical trial suggest.

The findings, presented here at a late-breaking research session at the American Academy of Dermatology (AAD) 71st Annual Meeting, show that the synthetically derived form of sodium deoxycholate promotes the breakdown of fat.

"ATX-101 causes adipocytolysis, which is the rupture of the fat cells leading to reabsorption in the body," lead investigator Susan Weinkle, MD, a private practice dermatologist in Bradenton, Florida, told Medscape Medical News. "The fat cell dies and is gone forever," she said.

The researchers looked at 165 people treated at 21 centers. Patients received 2 mg/cm2 deoxycholic acid in microinjections using a 30 G needle every 2 mm across a grid pattern on the submental region. Patients received up to 6 sessions spaced 28 days apart.

Physicians and patients rated each treatment session as well as results 3 months after the final injection using a validated scale for mild, moderate, or severe submental fat appearance.

"There was a demonstrated reduction in submental fat from both the clinician and patient perspective," Dr. Weinkle said.

At 12 weeks past the final treatment, physicians reported that 87% of patients achieved a one-point or greater improvement on the rating scale.

In addition, 83% of patients reported "significant improvement" at the follow-up assessment. "That is major," Dr. Weinkle said. "I like having happy patients."

Significant Improvement

Patients said they felt less bothered by their double chin, less self-conscious, and younger, Dr. Weinkle explained. "Some felt they looked like they lost weight even thought their BMI and weight remained the same."

Most patients (86%) reported they were "at least slightly satisfied" with their appearance and 94% reported they were "at least slightly satisfied" with their treatment.

Asked by Medscape Medical News to comment on the findings, Doris Day, MD, a private practice dermatologist in New York City, said, "This is an area of great concern for dermatologists. We can do so much to help our patients look younger and rejuvenate." However, she added, unless you perform liposuction or send patients to plastic surgery, "it's really difficult to get clinically significant, reliable results in the submental area."

Dr. Day says she likes the rigor of this study and other deoxycholic acid research as the product makes its way through the approval process with the US Food and Drug Administration. The clinical trials are blinded, controlled, and properly done, she said. "The outcomes will be reliable and real, and that means so much."

The treatment is not as easy as it sounds, Dr. Day pointed out. The patient goes through a lot. "There is recovery time and there can be some swelling and discomfort right after the procedure," she said.

However, she added, "The results have been impressive and they seem to be lasting." Dr. Day says she is looking forward to this product being approved and available on the market, and she hopes the indication will expand for use under the eye, around the arms, belly, knees, and other areas where patients have concerns.

Skin laxity following the removal of fat is also a concern. The researchers point out that approximately 96% of patients experience unchanged or improved laxity on a grading scale.

Skin Laxity

"We recognize that not only getting rid of fat is important," Dr. Weinkle said. "Histologically you see some collagen septa forming at 28 days, which translates into some skin tightening in that area."

Treatment-related adverse events occurred in 92% of participants. "These were mild to moderate and importantly, transient. Bruising, numbness, pain, edema, and erythema," Dr. Weinkle reported. "These went away quickly and caused only minor bother for patients."

The investigators also assessed vital signs and laboratory measures. They observed no systemic changes as fat cells were being destroyed and presumably removed by macrophages, including no clinically significant changes in blood lipid levels.

The investigators plan to report 12-month, long-term safety and efficacy results next.

This study was funded by Kythera Biopharmaceuticals. Dr. Weinkle is an advisor, consultant, and researcher for Kythera. Dr. Day reported no relevant financial relationships.

American Academy of Dermatology (AAD) 71st Annual Meeting. Late-breaking research presented March 2, 2013.