ORLANDO -- Three-fourths of men with moderate to severe Peyronie's disease had clinically and subjectively meaningful improvement a year after treatment with an enzyme that dissolves scar tissue, investigators reported here.
After 52 weeks of follow-up, 25% of patients had penile curvature ≤20° and 75% had curvature ≤45°. The responding patients reported meaningful change, which associated with improvement in penile curvature ranging from 25.5% to 69.8%.
Treatment with collagenase clostridium histolyticum (CCH, Xiaflex) was associated with several cases of corporal rupture due to early resumption of sexual activity, but otherwise the treatment has caused few problems, , reported at the American Urological Association meeting.
"The results appear durable, as we've seen no evidence of recidivism at this point," Hellstrom, of Tulane University in New Orleans, told ľֱ. "We did not formally assess quality of life, but we did use a questionnaire that showed that the patients subjectively corroborated the objective improvement that we observed."
At the 2013 AUA meeting, Hellstrom reported initial findings from two phase III trials of CCH conducted in the U.S. and Australia. The results showed almost half the patients met response criteria after 6 months, defined as at least 20% improvement in penile curvature and at least a 1-point improvement on the validated questionnaire.
Hellstrom presented updated results extended to 52 weeks for 545 men treated with CCH in the two placebo-controlled trials combined. The treatment regimen consisted of as many as eight injections of CCH administered in four treatment sessions 6 weeks apart. The men were instructed in penile bending and stretching to aid in restoring normal shape.
The 52-week assessment consisted of evaluation of penile curvature and change in the Global Assessment of Peyronie's Disease (GAPD). An improvement ≥1 in the GAPD was defined as clinically meaningful.
Patients who responded to the treatment (penile curvature ≤20°) had a mean baseline penile curvature of 41.3°, which improved to a mean of 11.9° after 52 weeks. The patients had a mean score of 2.4 on the GAPD, which has a range of -3 to +3.
Patients with penile curvature of 21° to 30° had mean improvement of 42.7%, and those with curvature of 30° to 45° had a mean improvement of 25.5%.
The ability to achieve erections was a requirement for participation in the study. A year later, all of the men who responded to the treatment reported being able to have erections sufficient for intercourse.
The most notable adverse events were five cases of corporal rupture, three of which required surgical repair. Hellstrom said all three patients had engaged in "vigorous" intercourse within a week of a treatment cycle. Given that CCH has received FDA approval, patients should be advised to wait 1 to 2 weeks after a treatment cycle before engaging in sexual intercourse.
Another report from the same two randomized trials analyzed the effect of time between first and second injection of CCH on penile curvature at 6 weeks. The protocol allowed investigators discretion to administer a second dose of CCH 24 to 72 hours after the first. The analysis showed that 6-week results were similar regardless of the interval between the first and second injection, said , of Baylor College of Medicine in Houston.
Administration of the second dose of CCH 24 hours after the first was associated with mean improvement in penile curvature of 12.1% at 6 weeks. The 6-week change was 13.7% in patients who received the second dose 48 hours after the first, and 12.2% in men who received the second dose 3 days after the first.
Disclosures
The study was supported by Auxilium Pharmaceuticals.
Hellstrom disclosed a relevant relationship with Auxilium, as did most investigators in the current analysis and the two randomized trials.
Primary Source
American Urological Association
Hellstrom WJG, et al "Meaningful change in Peyronie's disease following treatment with collagenase clostridium histolyticum: results from two large, double-blind, randomized, placebo-controlled trials" AUA 2014; Abstract PD22-02.
Secondary Source
American Urological Association
Lipshultz LI, et al "Effect of time between first and second injection of collagenase clostridiumhistolyticum on penile curvature deformity during the first treatment cycle of men with Peyronie's disease" AUA 2014; Abstract PD22-04.