Viragen Files Patent Application for Drug to Target SARS

PLANTATION, Fla. -- Viragen, Inc. announces that it has filed a patent application covering the use of natural human leukocyte-derived alpha interferon for the treatment and prevention of severe acute respiratory syndrome (SARS).

"Previous reports have identified alpha interferon as a prime candidate for the treatment of SARS," stated Viragen's director of research, William H. Stimson. "Groundbreaking research has determined that the main causing agent of SARS belongs to the coronavirus family. Previous studies in experimental coronavirus infections have found that a relatively high dosage of alpha interferon (9 MIU/day), begun shortly before virus challenge, provided protection against both infection and illness.(1) We believe natural, leukocyte-derived interferon is worthy of consideration in the experimental treatment of SARS and we are supporting appropriate research in this important area by providing samples of our product to international research organizations for evaluation."

The majority of alpha interferons that are marketed are single-subtype recombinant interferons. Therapy resistance is not unusual with recombinant interferons with a significant percentage of patients failing to respond to standard therapy. In some instances, recombinant interferon is rejected by the patient's immune system, usually caused by the formation of neutralizing antibodies that may lead to a loss of clinical efficacy. Also, many patients cannot tolerate the adverse side effects sometimes associated with recombinant therapy. High doses of recombinant interferon may cause serious, even life-threatening side effects.

Viragen has observed that in many cases, especially when higher dosages are required, its natural interferon appears to offer many advantages to recombinant interferon regimens, particularly against viral diseases:

* Natural interferon is very similar to interferon secreted by the human

immune system during a normal virus infection, significantly lowering

the risk of the drug being rejected.

* Natural interferon contains the multiple subtype composition that is

characteristic of interferon produced by the human body. It is

believed that this may result in a broader spectrum of anti-viral

activity with each subtype perhaps showing a specific biological

activity.

* Natural interferon does not appear to cause the formation of

neutralizing antibodies.

* Natural interferon is significantly less immunogenic than recombinant

interferon. It should be far better tolerated by patients with fewer

side effects and thus allow for higher doses to be administered to

maximize the benefits of the therapy.

According to the World Health Organization, a cumulative total of 7,864 probable SARS cases with 643 deaths have been reported from 32 countries with the highest concentrations reported in China, Hong Kong and Taiwan. Currently, there is no effective treatment for SARS and global health agencies are seeking to evaluate potential treatment strategies.

Viragen is a biotechnology company specializing in the research, development and commercialization of natural and recombinant protein-based drugs designed to treat a broad range of viral and malignant diseases. These protein-based drugs include human natural alpha interferon, monoclonal antibodies, peptide drugs and therapeutic vaccines.

References:

(1) Hayden, F. Use of interferon for prevention and treatment of respiratory viral infections. In: Antiviral Therapy New Directions for clinical application and research. John Mills and Lawrence Carey Ed. 1986.

Source: Viragen, Inc.