ViroPharma Initiates Phase 2 Study of VP 20621 for Prevention of Recurrence of Clostridium difficile Infection (CDI)

EXTON, Pa., May 19, 2011 /PRNewswire/ -- ViroPharma Incorporated (Nasdaq: VPHM) today announced initiation of a Phase 2 dose-ranging clinical study to evaluate the safety, tolerability, and efficacy of VP 20621 for prevention of recurrence of Clostridium difficile infection (CDI) in adults previously treated for CDI.

The objectives of this randomized, double-blind, placebo-controlled, dose ranging study are to evaluate the safety and tolerability of VP 20621 dosed orally for up to 14 days in adults previously treated for CDI; characterize the frequency and duration of stool colonization with VP 20621 strain of C. difficile; evaluate the efficacy of VP 20621 for prevention of recurrence of CDI; and select a dose regimen of VP 20621 to be used in future studies.  Eligible subjects will have been diagnosed with CDI and treated with metronidazole or oral vancomycin.  Subjects will be randomized into four different therapy groups, with study drug administered once daily after completion of CDI antibiotic treatment and continuing for up to 14 days.  Each subject will be followed for a total of 6 months.  The study will enroll at least 240 subjects, and will be conducted in North America and Europe.  

"Recurrence of CDI represents a therapeutic challenge with substantial associated morbidity, mortality and compromised quality of life, often requiring prolonged and repeated treatment courses," commented Colin Broom, M.D., ViroPharma's chief scientific officer.  "There are no immediate solutions on the horizon for prevention of recurrent CDI following antibiotic treatment.  However, based on the Phase 1 data with VP 20621, we are encouraged that this novel approach may one day fill this unmet clinical need."

About VP 20621

Antibiotics including those used to treat acute C. difficile infection (CDI) disrupt the normal gastrointestinal flora which renders individuals susceptible to C. difficile colonization.  Orally-dosed liquid VP 20621 utilizes non-toxigenic spore-based technology as a potential means of recolonization and protection. The goal of VP 20621 dosing following antibiotic exposure is to colonize with this non-toxigenic strain of C. difficile and to prevent colonization and infection with toxigenic strains, thereby preventing disease. VP 20621 may have therapeutic utility in the prevention of recurrence following treatment of acute CDI and in the primary prevention of CDI.  A Phase 1 escalating dose study included healthy subjects above 60 years of age who were pre-dosed with oral vancomycin to disrupt their gastrointestinal flora and render them potentially susceptible to C. difficile colonization. In this study, all subjects who received VP 20621 had positive non-toxigenic C. difficile stool cultures by day 6, suggesting that VP 20621 rapidly colonizes the susceptible GI tract.  The most common side effects observed following multiple doses of VP 20621 were mild loose or watery stools on a single study day that resolved despite continued dosing, mild burning sensation on the tongue, and mild dyspepsia.

About Vancocin® (vancomycin hydrochloride capsules, USP)

Vancocin® Capsules (vancomycin hydrochloride capsules, USP) is the only antibiotic approved to treat two significant bacterial infections of the lower digestive tract. It is administered orally for treatment of enterocolitis caused by Staphylococcus aureus (including methicillin-resistant strains) and antibiotic-associated pseudomembranous colitis caused by Clostridium difficile. Vancocin Capsules are contraindicated in patients with known hypersensitivity to vancomycin.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Vancocin Capsules and other antibacterial drugs, Vancocin Capsules should only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. Adverse events include nephrotoxicity, ototoxicity, reversible neutropenia and "Red Man's Syndrome." Infrequently, allergic reactions have been reported. Clinically significant serum concentrations have been reported in some patients treated with Vancocin Capsules for pseudomembranous colitis caused by C. difficile. It is noteworthy that total systemic and renal clearance of vancomycin are reduced in the elderly. Monitoring of serum concentrations may be appropriate in patients with renal insufficiency and/or colitis.

About Clostridium difficile

One of the most serious problems facing the U.S. healthcare system today is hospital-acquired infections (HAIs) and Clostridium difficile infection is one of the most common and devastating HAIs.  The incidence of C. difficile observed in U.S. healthcare facilities more than doubled approximately every five years since 1999 and the  reported mortality rates from C. difficile in the U.S. have more than quadrupled in the last decade to 23.7 per million.  Elderly patients exposed to antibiotics, long-term care patients, or those who have a serious underlying illness are at greatest risk to contract the disease.  Typical symptoms include diarrhea (which can be severe), fever, nausea, abdominal pain, and dehydration, though cases can lead to life-threatening complications such as megacolon, peritonitis and perforation of the colon.

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 the Company's current expectations or forecasts of future events. Forward-looking statements in this press release include statements regarding the timing and nature of ViroPharma's clinical development programs, including statements that VP 20621 may potentially protect a patient from colonization with toxin-producing strains of C. difficile and VP 20621 may significantly reduce the incidence of recurrent disease for patients with CDI. Our actual results could differ materially from those results expressed in, or implied by, these forward-looking statements. The development and commercialization of pharmaceutical products is subject to risks and uncertainties. The studies described in this press release represent the initial human studies with VP 20621 and the results of the Phase 2 study may not be predictive of how VP 20621 will perform in future studies. There can be no assurance that we will conduct additional studies with VP 20621 in the timeframes we expect or at all, or that VP 20621 can significantly reduce the incidence of recurrent disease for patients with CDI. The FDA or EMA may view the data regarding VP 20621 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 VP 20621. These factors, and other factors, including, but not limited to those described in ViroPharma's annual report on Form 10-K and quarterly reports on Form 10-Q filed with the Securities and Exchange Commission during 2010, could cause future results to differ materially from the expectations expressed in this press release. The forward-looking statements contained in this press release 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