Efficacy and Safety of Two Resilient Hyaluronic Acid Fillers in the Treatment of Moderate-to-Severe Nasolabial Folds: A 64-Week, Prospective, Multicenter, Controlled, Randomized, Double-Blinded, and Within-Subject Study

BACKGROUND: A range of monophasic dermal fillers made of high-molecular-weight hyaluronic acid (HA) chains with reduced cross-linking was developed for aesthetic procedures. OBJECTIVE: The efficacy, durability, and safety of 2 of these resilient HA (RHA) fillers, and their noninferiority to an effective HA comparator available in the United States, were tested in the treatment of dynamic facial wrinkles. METHODS: A 15-month, prospective, multicenter, active-controlled, randomized, double-blinded, split-face clinical trial was carried out on 174 subjects presenting moderate-to-severe bilateral nasolabial folds (NLFs). Assessed parameters included improvement on a proprietary Wrinkle Severity Rating Scale (WSRS) and Global Aesthetic Improvement Scale, according to Blind Live Evaluators, subjects, and treating investigators. Self-perception was evaluated with FACE-Q and satisfaction scales. RESULTS: The per-protocol populations included 67 and 62 subjects of all Fitzpatrick skin-phototypes, in the 2 comparison groups. Significant improvement of mean WSRS scores and associated responder rates established the noninferiority of RHA fillers to their comparator, over 15 months. Aesthetic improvement and subject satisfaction were durably high, with no meaningful differences between the fillers. Treatments were safe and well tolerated. CONCLUSION: The 2 RHA fillers are at least equivalent to a well-established comparator for the correction of NLF in subjects of diverse skin-phototypes.