CHICAGO The first large-scale trial of calcium hydroxylapatite in patients with Fitzpatrick skin types IV-VI showed no keloid formation, hypertropic scarring, or skin discoloration when used to treat nasolabial folds.
Although the reasons for scarring and keloids are not clear, anecdotally these side effects appear to present more in patients with darker skin types, lead investigator Dr. Ellen Marmur, chief of dermatologic surgery at Mount Sinai School of Medicine, New York, said in an interview.
"This study liberates many women and men with darker skin types to undergo cosmetic filler treatments with calcium hydroxylapatite," she said. "Past concerns about keloid scarring and discoloration now can be minimized, if not totally alleviated, for these patients.
"Their safety profiles matched those of the larger safety studies in lighter skin types showing this filler is safe to use in all skin types," she added.
The open-label, multicenter, nonrandomized prospective trial enrolled 100 patients with moderate to severe nasolabial folds and Fitzpatrick skin types IV (24%), V (35%), and VI (41%). Calcium hydroxylapatite 0.6 mL2.8 mL (mean 1.24 mL) was injected subdermally with a 25- to 27-gauge needle using a linear threading/fanning technique.
The mean patient age was 52 years and 94 were female; 85% were African American, 12% were Hispanic, 2% were Asian, and 1%, other.
Evaluation of 100 patients at 3 months and 98 patients at 6 months revealed no keloid formation, hypertrophic scarring, hypopigmentation, hyperpigmentation, or other clinically significant adverse events, Dr. Marmur and her associates reported in a poster at the American Academy of Dermatology's Academy 2008 meeting.
The study did not objectively evaluate efficacy, but treatment benefit, based on physician assessment, persisted for up to 6 months. Radiesse contains calcium-based microspheres suspended in a water-based gel that absorbs in 24 weeks, and builds volume by stimulating collagen growth around the implanted material.
Calcium hydroxylapatite (Radiesse) is approved for HIV-associated facial lipoatrophy, and is used as a cosmetic dermal filler.
The study was sponsored by BioForm Medical Inc., the maker of Radiesse. Dr. Marmur is on the medical education faculty for BioForm.