Safety and Effectiveness Evaluation of the High-intensity Focused Ultrasound Device for Lifting Lax Submental and Neck Tissue

This prospective, multicenter, randomized, evaluator-blinded, parallel-controlled, non-inferiority clinical investigation is conducted under an FDA Investigational Device Exemption (IDE #G250041) to evaluate the safety and effectiveness of the ULTRAFORMER MPT PLUS (Class II high-intensity focused ultrasound system) for aesthetic improvement of submental and neck tissue laxity. A total of approximately 273 subjects aged 30-65 years with mild-to-moderate skin laxity in the submental and neck areas will be enrolled across up to 5 U.S. investigational sites. Subjects will be randomized 1:1 to receive either ULTRAFORMER MPT PLUS or the comparator device (ULTHERA® System, Merz Aesthetics, USA). Primary endpoints include blinded investigator-assessed improvement using the validated Facial Laxity Grading Scale and safety outcomes based on the incidence and severity of device-related adverse events. Secondary endpoints include participant-reported improvement scores, digital image analysis, and durability of effect at 8-week and 12-week follow-ups. The study consists of two sequential safety stages (Stage 1A and 1B; 20 subjects total) followed by the pivotal Stage 2 phase (approximately 253 subjects). Data from the safety stages will be reviewed by an independent Data Safety Monitoring Board (DSMB) prior to progression to Stage 2. All treatments will be performed by trained investigators according to the protocol-defined parameters. Subjects will be evaluated at baseline, post-treatment, and during follow-up visits up to 6 months. The final statistical analysis will assess non-inferiority of ULTRAFORMER MPT PLUS to the predicate device with respect to the primary efficacy endpoint and confirm overall safety.