A Double Blind Study to Evaluate the Safety and Efficacy of Collagenase Clostridium Histolyticum (AA4500) in the Treatment of Lipoma

This study will evaluate the safety and efficacy of a Food and Drug Administration (FDA) approved drug (XIAFLEX) in the treatment of lipoma (fatty tumors). The fat in the lipoma is like normal fat except that it is enclosed in a balloon-like structure which is made of collagen (fibrous tissue). Treatment of the lipoma with an injection of XIAFLEX (a protein that breaks down collagen fibers) may dissolve the collagen/fibrous strands thereby decreasing the size of the lipoma or removing it. Each subject must have two lipomas; one lipoma to be treated with placebo and one lipoma to be treated with study drug, both to be observed similarly throughout the trial.