The Restylane package insert will be amended to include the study results. The company anticipates using this information in its promotional activities.
This randomized, evaluator-blinded, multi-center study enrolled 75 patients to study the safety and effectiveness of two different retreatment schedules, including duration of correction. Following a bilateral (split-face) design, each patient had both nasolabial folds corrected with Restylane. One side of the face was randomly selected to be corrected with Restylane and then re-treated at 4.5 months; the opposite side was re-treated at nine months.
Patients were evaluated using the Wrinkle Severity Rating Scale (WSRS), a five-point scale to measure visual severity of wrinkles where five is the most severe rating (extreme).
Restylane’s effective correction of nasolabial folds persisted for up to 18 months post initial treatment, regardless of re-treatment schedule. A vast majority of patients (97%) had at least one grade improvement on the WSRS at 18 months when retreated at 4.5 months. The study showed no significant difference between 4.5-month and nine-month re-treatment schedules for effectiveness and safety assessment, the company said.