ViroPharma Announces Completion of Enrollment in Phase 2 Study Evaluating Subcutaneous Delivery of Cinryze™ (C1 Esterase Inhibitor [Human])

EXTON, Pa., Oct. 25 /PRNewswire-FirstCall/ -- ViroPharma Incorporated (Nasdaq: VPHM) today announced that it has completed enrollment in its Phase 2 study evaluating subcutaneous delivery of Cinryze™ (C1esterase inhibitor [human]). This multi-center, open-label, multi-dose Phase 2 study is designed to evaluate the safety, pharmacokinetics and pharmacodynamics of subcutaneous versus intravenous administration of Cinryze in adolescent and adult subjects with hereditary angioedema (HAE).  The company expects to have preliminary data from this study by the end of this year, which will help inform the next steps of development for this mode of administration.

"The rapid enrollment into this study is indicative of the interest in, and also the potential for, prophylaxis with a subcutaneous form of Cinryze," commented Judy Johnson, ViroPharma's vice president of clinical pharmacology and nonclinical development. "We look forward to completing this important study which will inform our path forward, including the Phase 3 study design. We are excited by the potential of a subcutaneous option for patients who choose prevention of their HAE attacks."

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.  

Clinical Study Design

This is a multi-center, open-label multiple dose study in 24 adolescent and adult HAE patients in the US. All eligible subjects have been randomized into one of two treatment groups:  Patients received Cinryze via IV infusion two times per week for two weeks.  Then, following a 14-day washout period, subjects received Cinryze via subcutaneous administration at one of two dose levels (either 1000U or 2000U) two times per week for two weeks.  Safety and PK/PD assessments are being evaluated throughout each treatment period.  

About Cinryze™ (C1 esterase inhibitor [human])

Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived C1 esterase inhibitor product that has been approved by FDA for routine prophylaxis against angioedema attacks in adolescent and adult patients with HAE. C1 inhibitor therapy has been used acutely for more than 35 years in Europe to treat patients with C1 inhibitor deficiency. Cinryze is not currently approved in the European Union or any of its member states.

The most common adverse reactions observed have been upper respiratory infection, sinusitis, rash and headache. No drug-related serious adverse events (SAEs) have been observed in clinical trials. Severe hypersensitivity reactions may occur. Thrombotic events have occurred in patients receiving high dose off-label C1 inhibitor therapy well above the approved treatment dosage regimen. Monitor patients with known risk factors for thrombotic events. With any blood or plasma derived product, there may be a risk of transmission of infectious agents, e.g. viruses and, theoretically, the CJD agent. The risk has been reduced by screening plasma donors for prior exposure to certain virus infections and by manufacturing steps to reduce the risk of viral transmission including pasteurization and nanofiltration.

Cinryze is for intravenous use only. A dose of 1000 Units of Cinryze can be administered every 3 or 4 days for routine prophylaxis against angioedema attacks in HAE patients. Cinryze is administered at an injection rate of 1 mL per minute.

About Hereditary Angioedema (HAE)

HAE is a rare, severely debilitating, life-threatening genetic disorder caused by a deficiency of C1 inhibitor, a human plasma protein. This condition is the result of a defect in the gene controlling the synthesis of C1 inhibitor. C1 inhibitor maintains the natural regulation of the contact, complement, and fibrinolytic systems, that when left unregulated, can initiate or perpetuate an attack by consuming the already low levels of endogenous C1 inhibitor in HAE patients. Patients with C1 inhibitor deficiency experience recurrent, unpredictable, debilitating, and potentially life threatening attacks of inflammation affecting the larynx, abdomen, face, extremities and urogenital tract. Patients with HAE experience approximately 20 to 100 days of incapacitation per year. There are estimated to be at least 6,000 people with HAE in the United States.

For more information on HAE, visit the U.S. HAE Association's website at: http://www.haea.org/.

About ViroPharma Incorporated

ViroPharma Incorporated is an international biopharmaceutical company committed to developing and commercializing innovative products for physician specialists to enable the support of patients with serious diseases for which there is an unmet medical need, and providing rewarding careers to employees. ViroPharma commercializes Cinryze™ (C1 esterase inhibitor [human]) for routine prophylaxis against angioedema attacks in adolescent and adult patients with hereditary angioedema (HAE). ViroPharma commercializes Vancocin(R), approved for oral administration for treatment of antibiotic-associated pseudomembranous colitis caused by Clostridium difficile and enterocolitis caused by Staphylococcus aureus, including methicillin-resistant strains (for prescribing information on ViroPharma's commercial products, please download the package inserts at http://www.viropharma.com/Products.aspx). ViroPharma currently focuses its drug development activities in diseases including C1 esterase inhibitor deficiency and C. difficile.

ViroPharma routinely posts information, including press releases, which may be important to investors in the investor relations and media sections of our company's web site, http://www.viropharma.com/. The company encourages investors to consult these sections for more information on ViroPharma and our business.

Forward Looking Statements

Certain statements in this press release contain forward-looking statements that involve a number of risks and uncertainties. Forward-looking statements provide our current expectations or forecasts of future events, including the therapeutic indication and use, safety, efficacy, tolerability and potential of Cinryze and our focus, goals, strategy, research and development programs, and ability to develop pharmaceutical products, commercialize pharmaceutical products, and execute on our plans including clinical development activities with Cinryze related to subcutaneous administration. There can be no assurance that that our phase 2 clinical program with Cinryze utilizing subcutaneous administration will yield positive results or support further development of Cinryze for subcutaneous administration. The FDA or EMA may view the data regarding subcutaneous administration of Cinryze as insufficient or inconclusive, request additional data, require additional clinical studies, delay any decision past the time frames anticipated by us, limit any approved indications, or deny the approval of Cinryze for subcutaneous administration. These factors, and other factors, including, but not limited to those described in our annual report on Form 10-K for the year ended December 31, 2009 filed with the Securities and Exchange Commission, could cause future results to differ materially from the expectations expressed in this press release. The forward-looking statements contained in this press release are made as of the date hereof and may become outdated over time. ViroPharma does not assume any responsibility for updating any forward-looking statements. These forward looking statements should not be relied upon as representing our assessments as of any date subsequent to the date of this press release.

SOURCE ViroPharma Incorporated