Collagenase Clostridium Histolyticum for the Treatment of Edematous Fibrosclerotic Panniculopathy (Cellulite), : A Randomized Trial BACKGROUND Edematous fibrosclerotic panniculopathy (EFP; cellulite) is associated with thickening and contraction of collagen-rich subdermal septae. Collagenase clostridium histolyticum (CCH) may disrupt collagen-rich septae. OBJECTIVE To evaluate the safety and efficacy of CCH for treatment of EFP. MATERIALS AND METHODS In a randomized, double-blind study, women with moderate or severe EFP of the buttocks or posterolateral thighs (i.e., Clinician Reported Photonumeric Cellulite Severity Scale [CR-PCSS] and Patient Reported Photonumeric Cellulite Severity Scale [PR-PCSS] ratings of 3 to 4, and Hexsel Cellulite Severity Scale score ≤13) received up to 3 treatment sessions (Days 1, 22, and 43) of subcutaneous CCH 0.84 mg or placebo injections. End points included the percentage of 2-level and 1-level composite responders (i.e., had ≥2-level or ≥1-level improvement in CR-PCSS and PR-PCSS) at Day 71. RESULTS Three hundred seventy-five women (mean age, 46.5 years; 86.4% white) were randomly assigned to CCH (n = 189) or placebo (n = 186). At Day 71, the percentages of 2-level and 1-level composite responders were greater with CCH (10.6% and 44.6%, respectively) versus placebo (1.6% and 17.9%; p < .001 for both). The most common adverse events were injection-site related. CONCLUSION CCH significantly improved EFP appearance versus placebo; further evaluation of CCH for EFP (cellulite) is warranted.