IMPRESS I and II support the clinical efficacy and safety of collagenase C. histolyticum for the physical and psychological aspects of Peyronie disease.

The natural history of Peyronie's disease was evaluated in 97 men by means of a questionnaire. Disease duration ranged from 3 months to 8 years. Questions addressed pain, bending, ability for intercourse, over-all effect of the disease, psychological effects, treatments received and degree of disease progression. Approximately 40% of the patients found pain, bending, ability for intercourse and over-all effects to be unchanged during the course of the disease. Bending and ability for relations worsened in 40% of the patients during the same interval, while only 6% had worsening of pain. Of the patients 77% reported psychological effects due to Peyronie's disease, which improved in 28%, did not change in 36% and worsened in 36%. Over-all, 13% of the patients believed the disease to be one of gradual resolution, 47% believed there had been little or no change and 40% believed that the disease pattern was one of gradual progression. We found no statistically significant association between disease duration and spontaneous improvement in penile bending. A similar lack of statistical significance was found when improvement in a variety of categories was compared in patients who received no therapy versus those who received a variety of conventional medical therapies.

We investigated 49 men with Peyronie's disease in a prospectively randomized placebo controlled double-blind study, comparing the effects on plaque size and penile deformity of intralesional purified clostridial collagenase and saline placebo. For the group as a whole, treatment out-performed placebo (p < 0.007). When patients were analyzed with respect to disease severity, those with lesser deformity responded more favorably to treatment. The absolute angular change in patients responding to treatment was small. No significant side effects were noted within a 3-month followup.

Collagenase C. histolyticum treatment was well tolerated. We noted significant improvement in penile curvature and patient reported outcome symptom bother scores, suggesting that this may be a safe, nonsurgical alternative for Peyronie disease.