New hyaluronic acid gel outperforms bovine collagen

Key Points

White Plains, N.Y. - A new cohesive polydensified matrix hyaluronic acid (CPMHA, Belotero Balance; Merz) has outlasted bovine collagen in a 24-week study of nasolabial fold (NLF) correction and performed well in a 1.5-year follow-up study, according to Rhoda S. Narins, M.D., director of the Dermatology Surgery and Laser Center, White Plains, N.Y.; clinical professor of dermatology, New York University School of Medicine; and lead author of the studies.

Belotero is awaiting approval by the Food and Drug Administration. Meanwhile, Allergan will discontinue its collagen products - human-derived CosmoPlast and CosmoDerm and bovine products Zyderm and Zyplast - at the end of 2010. The company halted production of the products in 2009 but manufactured sufficient inventory to meet estimated market demand through the end of this year, according to Kelly Lao, manager of corporate communications. Johnson & Johnson announced in late 2009 that it was discontinuing Evolence (porcine collagen).

For the 24-week study, investigators randomized 118 subjects with moderate-to-severe bilateral NLFs to receive CPMHA and bovine collagen on opposite sides of the face. Before treating patients, investigators evaluated their NLFs using the Wrinkle Severity Rating Scale (WSRS) and tested patients for allergy to bovine collagen.

Investigators at six U.S. sites used any HA injection technique they preferred - such as cross-hatching, serial injection or tunneling - to achieve optimal aesthetic correction. They also gave pain-sensitive patients topical anesthetic or infraorbital nerve blocks before performing injections. Local anesthetic infiltration was not allowed, Dr. Narins says.

Researchers then evaluated results of initial treatments after two weeks and gave patients an optional touch-up treatment if needed, Dr. Narins says. Patients subsequently returned at weeks two, four, eight, 12, 16 and 24 after their last treatment for evaluation. Researchers also assessed safety through adverse event (AE) reports.

A dozen subjects failed to complete the study for various reasons. The study population was mainly female (92.4 percent) and Caucasian (96.6 percent), with skin type predominantly Fitzpatrick II or III and a mean age of 52.4 years.

Initial injection volumes averaged 1.16 mL for CPMHA, compared to 1.37 mL for collagen. Mean CPMHA injected at touch-up treatments was 0.81 mL (n = 94), versus 0.94 mL for collagen (n = 92).