Persistence of nasolabial fold correction with a hyaluronic acid dermal filler with retreatment: results of an 18-month extension study.

BACKGROUND: An 18-month persistence study reported nasolabial fold (NLF) improvements using a small gel-particle hyaluronic acid (SGP-HA) dermal filler lasted up to 18 months after one retreatment.
OBJECTIVE: [corrected] To evaluate the efficacy and persistence of SGP-HA for the correction of NLFs for up to 36 months. METHODS & MATERIALS: Subjects completing the 18-month persistence study were permitted to enroll in an 18-month extension trial. Most required second retreatments to achieve optimal correction of their NLFs. Subjects were followed for up to 36 months after their initial treatment. The primary efficacy measure was a 1-point improvement from baseline Wrinkle Severity Rating Scale (WSRS) score as determined by a blinded evaluator at different time points.
RESULTS: The study enrolled 52 subjects. Forty subjects required a second retreatment for optimum NLF correction. Mean retreatment volume was less than 50% of the initial treatment volume. Twenty-six subjects completed the study. Blinded assessments revealed that 94% to 100% of subjects maintained WSRS scores of 1 point or more higher than baseline throughout the study.
CONCLUSIONS: Participants in the 18-month extension of an 18-month SGP-HA persistence study continued to demonstrate improvement of NLFs up to 36 months after a second retreatment. The mean volume of SGP-HA required for optimum NLF correction decreased substantially with each retreatment. Subjects reported no treatment-related adverse events after the second retreatment.