A Multicenter, Randomized, Double-Blind, Parallel-Grouped, Positive-Controlled, Non-Inferiority Clinical Study to Evaluate the Efficacy and Safety of Injectable Calcium Hydroxylapatite Microsphere Hydrogel Fillers in the Correction of Nasolabial Fold in Chinese Subjects

Background Soft tissue fillers are used to improve the appearance of nasolabial folds (NLFs). This study aimed to compare the efficacy and safety of a new calcium hydroxylapatite microsphere hydrogel filler (Aphranel) versus Restylane for correcting NLFs. Methods In this multicenter, randomized, double-blind, parallel-grouped, positive-controlled, non-inferiority trial, 210 subjects were randomized to bilateral NLF treatment with Aphranel and Restylane on either side of the NLF. NLF was assessed before and right after injection and at the first week, first month, third, sixth, and 12 months. The primary efficacy endpoint was the WSRS improvement rate for the NLF, defined as >= 1 point improvement at Week 24. The secondary efficacy endpoints include the WSRS score assessed by investigators and the independent review committee (IRC) and the Global Aesthetic Improvement Scale (GAIS) evaluated by the subjects, investigators, and IRC over time. Randomization was performed using a computer-generated randomization list. To ensure the double-blind nature of the study, neither the physicians administering the injections nor the patients receiving them were aware of the specific product being used. All syringes were identical in appearance, with labels coded instead of indicating the product name. The preparation of the injection products was handled by nurses who were not involved in the treatment process, thereby maintaining the blinding of both the physicians and the patients to the treatment assignment. Results A total of 188 subjects (168 women and 20 men) completed the 12-month follow-up. The investigator-evaluated improvement rates using WSRS at 24 weeks were 84.04% for Aphranel and 78.72% for Restylane. The IRC-evaluated improvement rates using WSRS at 24 weeks were 72.34% for Aphranel and 70.21% for Restylane. Aphranel was shown to be statistically non-inferior to Restylane (P>0.05). Both the investigator and IRC-assessed WSRS scores over time showed that the mean scores for Aphranel were non-inferior to the mean scores for Restylane (all P>0.05). There was no difference between the Aphranel and Restylane groups according to the subjects, investigators, and IRC-assessed GAIS score at any time point (all P>0.05). Both devices' most frequently reported adverse events were injection site swelling and procedural pain. Conclusion This study confirms that Aphranel is an effective and safe treatment for correcting NLFs in Chinese subjects.