Auxilium announces analyses of Xiaflex from Phase 3 studies Highlights of the information presented include: 75% of men with PD treated with XIAFLEX in the IMPRESS pivotal studies had a clinically meaningful improvement in their penile curvature deformity by the end of the trials. These subjects reported an improvement of 25% or greater in penile curvature deformity. Peyronie's plaque tissue was excised and exposed to XIAFLEX in vitro. XIAFLEX preferentially degraded type I and type III collagen, predominant collagen types in PD plaques, while sparing type IV collagen present within connective tissues that surround arteries, large veins and nerves. There was no detectable effect of XIAFLEX on the structure of blood vessels, nerves, and fibroblasts at any dose evaluated.