AVR118 Suppresses Progression of Disease in Animal Model of Multiple Sclerosis Developed at The Weizmann Institute of Science.

Business Editors/Health/Medical Writers

YONKERS, N.Y.--(BUSINESS WIRE)--Dec. 9, 2003

Advanced Viral Research Corp. (OTCBB: ADVR) today announced that administration of its novel immunomodulator AVR118 (formerly known as Product R) in animals with induced experimental allergic encephalomyelitis (EAE) suppressed progression of this demyelinating neurological disease.

This animal model, developed by the Weizmann Institute of Science in Rehovot, Israel, serves as a potential model for the use of AVR118 in the treatment of the human auto-immune demyelinating disease, multiple sclerosis (MS).

EAE is a demyelinating disease of the central nervous system that serves as an animal model for multiple sclerosis. In experiments conducted at the Weizmann Institute, AVR118 was delivered to the animals through subcutaneously implanted infusion pumps for fourteen days concomitantly with the induction of the disease in rats by injection of basic myelin protein. AVR118 markedly inhibited the progression of experimental allergic encephalomyelitis in all the rats treated. Effects on the disease ceased when treatment with AVR118 was discontinued. Furthermore, when AVR118 was fed orally to experimental rats there was a dose-dependent suppression of the demyelination that marks EAE.

"The positive results observed with AVR118 in the animal model emphasizes the broad potential for treatment of auto-immune diseases based on the anti-inflammatory properties of this novel drug," said Maribel de Diego, Ph.D., ADVR's head of immunology. "It is likely that the therapeutic activity of AVR118 in EAE is due to the drug's modulating effects on cytokines and chemokines. The strong effects of AVR118 in suppressing the progression of the demyelinating disease in the model in rats serve as an impetus for future clinical study of the possible therapeutic role for AVR118 in multiple sclerosis."

Multiple Sclerosis

The prevalence rate of multiple sclerosis is 1 in 700 (0.14%) according to the National Institute of Allergy and Infectious Disease (NIAID); thus there are approximately 388,000 patients with the disease in the United States. The sex ratio of incident cases is about 2.3 to 1, women to men. The age of onset peaks between 20 and 30 years. Approximately 70% of patients manifest symptoms between the ages of 21 and 40. The risk of multiple sclerosis is higher both in temperate climates and among people of northern European decent.

"These animal studies provide clinicians with critical information necessary for future approval for human trials," said James T. D'Olimpio M.D., a clinical consultant to ADVR. "These results are highly relevant in validating the scientific principles that will lead the medical community into understanding a potentially new therapeutic class of drugs. These tests are an important first step in translating meaningful basic science to the bedside, where the resulting medications may help a wide variety of patients suffering the consequences of chronic disease and the inflammatory mechanisms that modulate this suffering."

ADVR's AVR118 (formerly known as Product R) represents a biopolymer chemistry that possesses novel immunomodulator activity. This peptide-nucleic acid, which to date has shown no indication of human toxicity, appears to stimulate the proinflammatory responses required to combat viral infections such as AIDS and human papilloma virus and to dampen aberrant autoimmune-type inflammatory responses, such as occur in patients with rheumatoid arthritis. Therefore, AVR118 has been termed a "switch-type" immunomodulator. AVR118 is in clinical trials in Israel for the treatment of cachexia (body wasting) in patients with AIDS.

For further information regarding Advanced Viral Research Corp., please visit our website at www.adviral.com.

Advanced Viral Research Corp., based in Yonkers, New York, is a biopharmaceutical firm dedicated to improving patients' lives by researching, developing and bringing to market new and effective therapies for viral and other diseases.

Note: This news release contains forward-looking statements that involve risks associated with clinical development, regulatory approvals, including application to the FDA, product commercialization and other risks described from time to time in the SEC reports filed by the Company. AVR118 (Product R) is not approved by the U.S. Food and Drug Administration or any comparable agencies of any other countries. There is no assurance that the Company will be able to secure the financing necessary to continue and/or complete the clinical trials of AVR118 or satisfy certain other conditions relating to clinical trials including obtaining adequate insurance on terms acceptable to the Company. The Company undertakes no obligation to update or revise the information contained in this announcement whether as a result of new information, future events or circumstances or otherwise.