Background: This is a report of the secondary endpoints, Subject Global Evaluation (overall improvement) and Subject Satisfaction scores, from a study designed to examine the efficacy of injectable poly-l-lactic acid for the correction of nasolabial fold wrinkles over 25 months.
Methods: A randomized, subject-blinded, parallel-group, multicenter clinical study was conducted to compare the effects of injectable poly-l-lactic acid with those of human collagen for the treatment of nasolabial fold wrinkles at 13 months following the last treatment. Injectable poly-l-lactic acid–treated subjects were followed for 25 months.
Results: From month 3 through month 13 following the last treatment, injectable poly-l-lactic acid–treated subjects (n = 116) reported significantly higher Subject Global Evaluation scores compared with human collagen–treated subjects (n = 117; p < 0.001). Overall Subject Global Evaluation scores for injectable poly-l-lactic acid–treated subjects were 99 percent at week 3, 91 percent at month 13, and 81 percent at month 25 (all times following the last treatment). In contrast, for human collagen–treated subjects, overall Subject Global Evaluation scores declined by 84 percent, from 96 percent at week 3 to 15 percent at month 13. Subject Satisfaction scores were significantly different (p < 0.01) between treatment groups beginning week 3 and continuing through month 13. Overall Subject Satisfaction scores were maintained for over 80 percent of injectable poly-l-lactic acid–treated subjects (n = 106) at month 25 after the last treatment.
Conclusions: Treatment of nasolabial fold wrinkles with injectable poly-l-lactic acid resulted in statistically significantly higher Subject Global Evaluation and Subject Satisfaction scores compared with human collagen at 13 months. Injectable poly-l-lactic acid–treated subjects maintained improvements for up to 25 months after treatment.