EXTON, Pa., May 28, 2013 /PRNewswire/ -- ViroPharma Incorporated (Nasdaq: VPHM), an international biopharmaceutical company committed to developing and commercializing innovative products that address unmet medical needs and rare diseases, today announced results of new data analyses from the randomized, placebo-controlled and open label clinical trials of Cinryze® (C1 esterase inhibitor [human]), the first and only C1 esterase inhibitor therapy approved for routine prevention of angioedema attacks in patients with HAE. Since neither of these clinical trials excluded patients who were on anabolic androgens (AA; attenuated androgens), analyses were conducted to evaluate how the use of AA impacted the outcome of subjects while on Cinryze.
In the randomized, placebo-controlled trial, 36.4 percent of subjects (8 of 22) were using AA for prophylaxis with a mean historical attack rate of 13.88 per 12 weeks. Five of these eight patients discontinued AA use prior to randomization. Among these five, the mean number of attacks over the 12-week placebo period was 15, compared to 6.8 attacks during the Cinryze treatment period; this represents a 54.7 percent decrease in attack rate which is similar to the reduction in attack rate (52 percent) from the overall study population.
In the open label study, 28.8 percent of subjects (42 of 146) were using AA for prophylaxis at screening and 23 of them discontinued AA during the study. The median number of attacks/month in subjects who discontinued AA was 3.00 (1.25, 11; interquartile range, IQR) at study entry which decreased to 0.00 (0.00, 0.31) during an average of 257 days in the study while taking Cinryze. Eight subjects continued on a stable dose of AA during open label treatment. The attack frequency/month of those subjects went from 3.5 (2.75, 4) at study entry to 0.26 (0.06, 0.71) after treatment with open label Cinryze. The other 11 subjects reduced but did not stop using AA; their median monthly attack frequency went from 2 (2, 3) to 0.24 (0, 0.67) at study completion. No drug interaction studies of Cinryze and AA have been conducted.