Results from an interim analysis completed after 31 months of follow-up in a five-year prospective multicenter study represent good news about the efficacy and safety of nasolabial fold correction using the current generation of a polymethylmethacrylate (PMMA) nonresorbable filler (Artefill, Suneva). This information may give surgeons the confidence to offer the product to patients interested in a long-term filler option, says Neil S. Sadick, M.D.
INTERIM RESULTS Top-line results from the interim analysis show treatment with the filler was associated with a low rate of histologically confirmed granulomas and high ongoing patient satisfaction. At 31 months, only five histologically confirmed granulomas were reported (0.49 percent); one resolved with no intervention, and the rest cleared with medical treatment. The proportion of patients reporting that they were satisfied or very satisfied with their cosmetic results was 82 percent at six months after the last injection and was nearly the same (80 percent) after 18 months."The FDA asked Suneva to do a five-year prospective safety study because hypersensitivity reactions were reported in the European literature using previous generations of the PMMA-based filler. Now in its third generation, this nonresorbable filler product has evolved in terms of its safety and utilization," says Dr. Sadick, clinical professor of dermatology, Weill Medical College of Cornell University, New York. "This ongoing safety study is the largest and longest prospective clinical study of dermal fillers conducted to date in the U.S. and European Union, as well as the first trial to differentiate clinically and histologically documented true granulomas from ectopic papules. Importantly, the rate of granulomas is very low, findings from histological evaluation show no granulomas were biofilm-related, and none required surgical intervention. There have also been no product recalls and no reported medical device events to date for this product," Dr. Sadick says.
SAFETY PROFILE COMPARISON In the United States, about 22,000 patients have been treated with the third generation of the PMMA-based filler since it was approved in 2006, and the granuloma rate in this post-marketing experience is about
In the prospective safety study, the four patients who received medical intervention for granuloma were treated with a topical or intralesional corticosteroid. In addition, one patient received intralesional 5-fluorouracil, and two patients were treated with oral antibiotics (macrolide alone or with doxycycline), although one of the latter patients had a concomitant respiratory tract infection.
ADDITIONAL AES Data for other adverse events reported in the five-year prospective study show that rates of nodularity of any type, persistent swelling and increased sensitivity after injection are lower compared with those recorded in the U.S. pivotal study of the filler. "The investigators participating in the five-year study have significant experience using intermediate and long-term fillers, but the types of various adverse events associated with this particular product appear to have decreased as the users' experience with the product increased," Dr. Sadick says.
Dr. Sadick says the material can be injected using a tunneling or linear threading technique, but he emphasizes that it must be implanted into the deep dermal or subdermal plane and without attempting to achieve overcorrection. "Most patients require just an initial treatment and a single touch-up at four to six weeks. Then the correction should be maintained for five to seven years," he says.
The longevity of the cosmetic correction achieved with the PMMA-based filler is believed to be secondary to dermal remodeling and fibroplasia development around the injected PMMA microspheres, which provide a scaffold for human collagen deposition and a nidus for upregulation of fibroblast activity.
A paper reporting the results of the 31-month interim analysis is in press in the Journal of Drugs in Dermatology. Dr. Sadick also suggests the following articles: Lemperle G, Knapp TR, Sadick NS, Lemperle SM. ArteFill permanent injectable for soft tissue augmentation: I. Mechanism of action and injection techniques. Aesthetic Plast Surg. 2010;34(3):264-272; Lemperle G, Sadick NS, Knapp TR, Lemperle SM. ArteFill permanent injectable for soft tissue augmentation: II. Indications and applications. Aesthetic Plast Surg. 2010;34(3):273-286).