ViroPharma Incorporated Release: Nine Abstracts Relating to Cinryze® (C1 Esterase Inhibitor [human]) Data Presented at 30th Congress of the European Academy of Allergy and Clinical Immunology (EAACI)

ISTANBUL, June 13, 2011 /PRNewswire/ -- ViroPharma Incorporated (NASDAQ: VPHM) today announced that data relating to Cinryze® (C1 esterase inhibitor [human]) from nine accepted abstracts were presented as poster presentations at the 30th Congress of the European Academy of Allergy and Clinical Immunology (EAACI), June 11 through 15, in Istanbul, Turkey. Of the nine posters, two contain new data and seven contain data previously presented at the 2010 International Scientific Conference of the World Allergy Organization (WAO), the 2010 Annual Meeting of the American College of Allergy, Asthma & Immunology (ACAAI), and the 2011 American Academy of Allergy Asthma & Immunology (AAAAI) Annual Meeting.

Cinryze is the first and only U.S. FDA-approved C1 esterase inhibitor therapy indicated for routine prophylaxis against angioedema attacks in adolescent and adult patients with hereditary angioedema (HAE), a rare, debilitating and potentially fatal disease. Currently, Cinryze is available only in the United States, and is not approved to treat acute angioedema attacks, for children with HAE, or for pre-procedural administration.

In Europe, the Committee for Medicinal Products for Human Use (CHMP) has adopted a positive opinion for Cinryze for treatment and pre-procedural prevention of angioedema attacks in adults and adolescents with hereditary angioedema (HAE), and routine prevention of angioedema attacks in adults and adolescents with severe and recurrent attacks of hereditary angioedema (HAE), who are intolerant to or insufficiently protected by oral prevention treatments or patients who are inadequately managed with repeated acute treatment.

HAE is a rare, debilitating and potentially life-threatening genetic disorder that affects at least 10,000 people in Europe. HAE is a variable disease due to a deficiency of C1 inhibitor, a human plasma protein that prevents swelling. Patients can experience unpredictable, recurrent, disabling and potentially deadly attacks of swelling that can affect the larynx, abdomen, face, extremities and genitourinary tract. If approved, Cinryze would be the first C1 esterase inhibitor product approved for preventative therapy of HAE across all of Europe.

"As we move closer toward providing Cinryze for HAE patients in Europe, it is important that we expand the awareness among the medical community of the available data on clinical experience with this important drug for patients with hereditary angioedema," commented Mark Sampson, MD, ViroPharma's vice president of clinical development and medical affairs, Europe. "HAE is a variable disease that can be seen by various physician specialties, and Cinryze is poised to be a comprehensive management option for European physicians and patients."

EAACI Poster Presentations (new data)

In a poster entitled, 'Use of Nanofiltered C1 Esterase Inhibitor (Human) [C1 INH-nf] for the Treatment of Gastrointestinal (GI) Attacks in Subjects with Hereditary Angioedema (HAE),' Dr. William Lumry, M.D., of the University of Texas Southwestern Medical School in Dallas, Texas discussed the potential for Cinryze to treat GI-localized HAE attacks. These data were compiled from an open-label, multicenter (29 sites) study that enrolled 113 subjects with a diagnosis of HAE. Gastrointestinal attacks represented the largest proportion (351/598, 59 percent) of HAE attacks in this study. Subjects received treatment with C1 INH-nf 1000U IV and could receive a second dose of C1 INH-nf 1000U if their symptoms had not improved by 60 minutes. The results cited on the poster included the following:

• Seventy-seven subjects experienced a total of 351 GI attacks, with 97 percent (339/351) achieving relief within 4 hours after C1 INH-nf administration; median time to beginning of relief was 30 minutes. This response time was comparable to the overall median response time for all attacks at all anatomic locations in this study (30 minutes).
• Among subjects treated for greater than one GI attack, the efficacy of C1 INH-nf did not diminish with subsequent repeated administration.
• Of the 113 subjects enrolled, the most common (three to five percent of subjects) adverse events were sinusitis, nasopharyngitis, streptococcal pharyngitis, HAE, constipation, cough, rash, and bronchitis.
• There were no hypersensitivity reactions, including anaphylaxis, related to C1 INH-nf. HBV, HCV, and HIV testing revealed no evidence of viral transmission. There was no evidence of development of clinically relevant anti-C1 INH antibodies.

In a poster entitled, 'Use of Nanofiltered C1 Esterase Inhibitor (Human) [C1 INH-nf] for the Treatment of Extremity and Facial Attacks in Subjects with Hereditary Angioedema (HAE),' Dr. Marc Riedl, M.D., of the University of California, Los Angeles, David Geffen School of Medicine presented the experience of 51 subjects who received C1 INH-nf to treat 156 facial and extremity attacks of HAE. Cutaneous attacks of the extremity (N=86) and face (N=70) represented the second largest proportion (156/598, 26 percent) of HAE attacks in this study. Subjects received treatment with C1 INH-nf 1000U IV and could receive a second dose of C1 INH-nf 1000U if their symptoms had not improved by 60 minutes. The results cited on the poster included the following:

• Ninety six percent of these attacks (149/156) achieved relief within 4 hours after C1 INH-nf administration; median time to beginning of relief was 30 minutes. This response time was comparable to the overall median response time for all attacks at all anatomic locations in this study (30 minutes).
• The efficacy of C1 INH-nf did not diminish with subsequent repeated administration. Of the 113 subjects enrolled, the most common (three to five percent of subjects) adverse events were sinusitis, nasopharyngitis, streptococcal pharyngitis, HAE, constipation, cough, rash, and bronchitis.
• There were no hypersensitivity reactions, including anaphylaxis, related to nf-C1 INH. HBV, HCV, and HIV testing revealed no evidence of viral transmission. There was no evidence of development of clinically relevant anti-C1 INH antibodies.

Additional EAACI Poster Presentations (previously presented data)

1. Open-Label Use of Nanofiltered C1 Esterase Inhibitor (Human) (C1 INH-nf) for the Treatment of Hereditary Angioedema (HAE) Attacks
2. Open-Label Use of Nanofiltered C1 Esterase Inhibitor (Human) (C1 INH-nf) for the Prophylaxis of Hereditary Angioedema (HAE) Attacks
3. Pre-procedure Administration of C1 Esterase Inhibitor (Human) (C1 INH-nf) for the Prevention of Hereditary Angioedema (HAE) Attacks after Medical, Dental, or Surgical Procedures
4. Site of Care of Nanofiltered C1 Esterase Inhibitor (Human) (C1 INH-nf) in Patients With Hereditary Angioedema (HAE)
5. Safety and Efficacy of Nanofiltered C1 Esterase Inhibitor (Human) (C1 INH-nf) for the Treatment of Laryngeal Attacks in Subjects with Hereditary Angioedema (HAE)
6. Open-Label Use of Nanofiltered C1 Esterase Inhibitor (Human) (C1 INH-nf) for Treatment of Acute Attacks of Hereditary Angioedema (HAE) in Pediatric Subjects
7. Open-Label Use of Nanofiltered C1 Esterase Inhibitor (Human) (C1 INH-nf) for Treatment or Prophylaxis of Acute Attacks of Hereditary Angioedema (HAE) in Pregnant Subjects

EAACI Symposium

ViroPharma is also sponsoring a scientific symposium on Monday June 13th at 13.30 hrs (1:30 PM) local time entitled, "New Strategies for Preventing Hereditary Angioedema (HAE) Attacks." This symposium, sponsored by ViroPharma through an independent educational grant, will be webcast live, and all content will be available for three additional months. It can be accessed at the following URL: http://go.podia.net/viropharma_istanbul_symposium_2011

About Cinryze® (C1 esterase inhibitor [human])

Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived C1 esterase inhibitor product that is approved by U.S. FDA for routine prophylaxis against angioedema attacks in adolescent and adult patients with HAE. In Europe, on March 17, 2011, the CHMP adopted a positive opinion for Cinryze for treatment and pre-procedure prevention of angioedema attacks in adults and adolescents with hereditary angioedema (HAE), and routine prevention of angioedema attacks in adults and adolescents with severe and recurrent attacks of hereditary angioedema (HAE), who are intolerant to or insufficiently protected by oral prevention treatments or patients who are inadequately managed with repeated acute treatment. The CHMP positive opinion forms the scientific basis for the European Commission to issue a binding decision for a Centralized Marketing Authorization, which is expected in the second quarter of 2011.

Severe hypersensitivity reactions to Cinryze may occur. Thrombotic events have occurred in patients receiving Cinryze for routine prophylaxis, and in patients receiving off-label high dose C1 inhibitor therapy. 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 donors for prior exposure to certain virus infections and by manufacturing steps to reduce the risk of viral transmission including pasteurization and nanofiltration. 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.

Cinryze is approved for intravenous use only.

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 6,500 people with HAE in the United States, and at least 10,000 people across Europe.

For more information on HAE, visit the U.S. HAE Association's website at: www.haea.org or the HAEi (International Patient Organization for C1 Inhibitor Deficiencies) at www.haei.org.

About ViroPharma Incorporated

ViroPharma Incorporated is an international biopharmaceutical company committed to developing and commercializing novel solutions for physician specialists to address unmet medical needs of patients living with diseases that have few if any clinical therapeutic options, including C1 esterase inhibitor deficiency, pediatric epilepsy and C. difficile infection (CDI). Our goal is to provide rewarding careers to employees, to create new standards of care in the way serious diseases are treated, and to build international partnerships with the patients, advocates, and health care professionals we serve. ViroPharma's commercial products address diseases including hereditary angioedema (HAE) and CDI; for prescribing information on our products, please download the package inserts at http://www.viropharma.com/Products.aspx.

ViroPharma routinely posts information, including press releases, which may be important to investors in the investor relations and media sections of our company's website, 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. There can be no assurance that that the data presented during the 30th Congress of the European Academy of Allergy and Clinical Immunology (EAACI) regarding Cinryze is predictive of how Cinryze will perform in commercial usage. Cinryze is currently available only in the United States. Cinryze is not approved in the U.S. for acute treatment of attack, children with HAE or for pre-procedure prophylaxis. We cannot assure that current or future studies with Cinryze in the patient populations described in the EAACI presentations will demonstrate the same or similar safety and efficacy profile of Cinryze as described in the data presented during the 2011 EAACI. 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, 2010 and 10-Q for the quarter ended March 31, 2011 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