ViroPharma initiates Phase 2 clinical study to evaluate Cinryze

ViroPharma Incorporated (Nasdaq: VPHM) today announced that it has initiated an open-label, single-dose Phase 2 study to evaluate doses of Cinryze™ (C1 esterase inhibitor [human)] for treatment of acute angioedema attacks in children less than 12 years of age with hereditary angioedema (HAE).  Cinryze was approved by the U.S. Food and Drug Administration in October 2008 for routine prophylaxis against angioedema attacks in adolescent and adult patients with HAE.  Cinryze is not approved in the US for acute treatment of attacks or in pediatric patients below the age of 12 years.  

The study design was agreed upon with the Pediatric Committee of the European Medicines Agency (EMA) as a component of the Pediatric Investigational Plan (PIP) that was approved prior to the Company's recent submission of a Marketing Authorization Application (MAA) for Cinryze. The objectives of the study are to evaluate the dose response and the PK/PD of IV administration of Cinryze for the treatment of acute angioedema attacks in children less than 12 years of age with HAE; and to determine the safety and tolerability following IV administration of Cinryze in this study population.

"Hereditary angioedema is an autosomal dominant disease, meaning that each child of a parent with HAE has a 50/50 chance of also being afflicted with the disease; so understanding pediatric dosing requirements is essential for such genetic diseases," commented Colin Broom, M.D., ViroPharma's chief scientific officer. "The Cinryze clinical development program includes a pediatric dataset that is among the largest for any HAE therapy.  However, we want to further assess various pediatric dosing regimens, particularly for young children. This study will evaluate the efficacy and safety of a range of doses in children and measure plasma concentrations of C1 esterase inhibitor following administration of Cinryze as treatment of acute HAE attacks."

Clinical Study Design

This multi-center, open-label study will be conducted in 12 pediatric patients. Eligible subjects (2 years to <12 years of age) will receive treatment for a single acute HAE attack.  Cinryze will be administered as a single IV infusion of 500 U, or 1000 U (for subjects 10-25 kg) and 1000 or 1500 U (for subjects >25 kg). Patients will be evaluated for HAE symptom relief and will have blood samples collected for complement levels including antigenic and functional C1 INH and C4.  The primary efficacy assessment will be made based on clinical response observed within 4 hours after dosing.