A Retrospective Analysis of Safety in Participants Treated with a Hybrid Hyaluronic Acid and Calcium Hydroxyapatite Filler.

Background: Limited long-term safety data are published on HA/CaHA/L, a hybrid dermal filler combining hyaluronic acid (HA), calcium hydroxyapatite (CaHA), and lidocaine (L). Methods: This retrospective multicenter study assessed treatment-emergent adverse events (TEAEs) in adults treated with HA/CaHA/L. The full analysis set (FAS) included eligible consented adults (N = 403); the long-term safety analysis (LTSA) set included FAS participants with greater than or equal to 12-months HA/CaHA/L exposure (n = 243). Results: Participants were majority female (94.0%), with Fitzpatrick skin phototypes II/III (80.1%) and a mean age of 50.1 years. Most participants (86.4%) received one HA/CaHA/L treatment. The median time between participants' first HA/CaHA/L treatment and chart review was 15.4 months. Participants received a mean of 2.2 mL (0.5-8.9 mL) filler per treatment. Treated areas were predominantly malar (71.2%) and mandible (69.7%) regions. Most participants (95.0%) had one or more aesthetic treatments other than HA/CaHA/L [eg, other dermal fillers (84.1%), botulinum toxin (63.3%)]. Nineteen (4.7%) FAS participants had 20 documented TEAEs; most (3.5%, n = 14 participants) were mild in severity. Twelve TEAEs in 11 participants (2.7%) were related to HA/CaHA/L: induration (three, 0.7%), edema (3, 0.7%), and implant site nodules (five, 1.2%), which were noninflammatory and likely related to product placement. Among the LTSA, 15 (6.2%) participants had 16 documented TEAEs (six edema, five implant site nodules, one inflammation, three skin induration, one hypersensitivity); most were mild in severity. Nine TEAEs in eight participants (3.3%) were HA/CaHA/L-related. No treatment-emergent serious AEs were reported. Conclusion: The data from this noninterventional retrospective study support the favorable longer term (>12 month) safety profile of HA/CaHA/L.