Efficacy, Safety, and Durability of Response of Collagenase Clostridium Histolyticum-aaes for Treating Cellulite

Background: Collagenase clostridium histolyticum-aaes (CCH) enzymatically releases fibrous septa that contribute to the skin dimpling characteristic of cellulite. Long-term safety/duration of efficacy (durability) results from an open-label extension (OLE) of a randomized, double-blind, placebo-controlled trial (RCT) evaluating CCH efficacy/safety for moderate-to-severe cellulite of the buttocks or posterolateral thighs in women was assessed. Efficacy/safety of CCH treatment/retreatment during OLE was also evaluated. Methods: After RCT unblinding, women could enroll in OLE for assessment of long-term CCH durability (observation only, up to day 720) or CCH treatment/retreatment, the latter in women with moderate-to-severe buttock/posterolateral thigh cellulite [Clinician Reported Photonumeric Cellulite Severity Scale (CR-PCSS) and Patient Reported PCSS (PR-PCSS) scores of 3/4; Hexsel Cellulite Severity Scale score ≤13]. A treatment/retreatment course comprised 1 or 2 courses of 3 sessions (0.84-mg CCH injected at days 1, 22, and 43). CCH efficacy/safety was assessed at baseline, days 22, 43, 71, and quarterly at day 360. Results: Of the 259 OLE participants, 53 were observed for long-term CCH durability. For those who were ≥2-level composite responders during RCT (≥2-point CR-PCSS/PR-PCSS score improvements), CCH effect was durable (scores did not reach RCT baseline levels) in all women on days 180 (19/19), 360 (16/16), and 720 (7/7). Of the 200 women receiving CCH treatment/retreatment, more than 75% had ≥1-level improvement in patient and clinical assessments at day 71. The most common adverse events were injection-site bruising and pain. Conclusions: CCH treatment provided durable improvement in moderate-to-severe buttock/thigh cellulite and was generally well tolerated. Repeated CCH exposure did not increase adverse event risk or reduce efficacy.