EXTON, Pa., Aug. 1, 2013 /PRNewswire/ -- ViroPharma Incorporated (NASDAQ: VPHM) today announced that following discussion with the Center for Biologics Evaluation and Research (CBER) division of the U.S. Food and Drug Administration, ViroPharma is going to discontinue this Phase 2 study. The discontinuation of the study is a precaution related to the emergence of an unexpected incidence and titer of non-neutralizing anti-rHuPH20 antibodies in a number of patients with the formulation being used in this study. These antibodies have not been associated with any adverse clinical effects and are of unknown clinical significance.
The study was fully enrolled and 41 patients completed at least one dosing arm of study drug with a total of 20 patients having completed both dosing arms. These data will be informative for design of future subcutaneous administration studies.
In parallel with the conduct of this Phase 2 study, we have developed an optimized, low-volume subcutaneous formulation of Cinryze. As a result, ViroPharma expects to conduct a Phase 3 subcutaneous registration study with this alternative formulation in the same time frame that had been anticipated previously for the combination product.ViroPharma will be conducting a conference call to discuss the second quarter financial results and other business this morning and will provide additional information related to the subcutaneous administration development program. Cinryze is approved in the United States as intravenous (IV) administration for routine prophylaxis against angioedema attacks in adolescent and adult patients with hereditary angioedema (HAE), and in Europe for routine prevention, pre-procedure prevention and acute treatment of angioedema attacks in adolescent and adult patients with HAE. Conference Call and Webcast ViroPharma is hosting a live teleconference and webcast with senior management to discuss the financial announcement, guidance, and all other operational results of the first quarter on August 1, 2013 and discuss developments in the subcutaneous Cinryze clinical development program at 9:00 a.m. Eastern. To participate in the conference call, please dial (800) 874-4559 (domestic) and (302) 607-2019 (international). After placing the call, please tell the operator you wish to join the ViroPharma investor conference call. Alternatively, the live webcast of the conference call can be accessed via ViroPharma's website at http://www.viropharma.com. Windows Media or Real Player will be needed to access the webcast. An audio archive will be available at the same address until August 15, 2013. About Cinryze® (C1 esterase inhibitor [human]) Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived C1 esterase inhibitor product. In the U.S., Cinryze is approved by the FDA for routine prophylaxis against angioedema attacks in adolescent and adult patients with HAE. In the E.U., the product is approved by the EMA for the 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. Cinryze is for intravenous use only. Severe hypersensitivity reactions to Cinryze may occur. Thrombotic events have occurred in patients receiving Cinryze, 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.