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Myriad Genetics Submits IND on Vivecon New HIV Maturation Inhibitor
  Novel Mechanism of Action, Active Against Drug-Resistant HIV Salt Lake City, UT, December 04, 2007-Myriad Genetics, Inc. (NASDAQ: MYGN) announced today that it has submitted an Investigational New Drug (IND) application to the United States Food and Drug Administration to begin human clinical trials with its drug candidate, Vivecon■ (MPC-9055), for the treatment of AIDS.
Vivecon is a novel, small-molecule drug candidate that Myriad has designed to be taken orally and to inhibit viral maturation. The drug candidate inhibited viral particles from reaching maturity, so they were incapable of infecting other cells, by targeting the capsid-SP1 cleavage site in the HIV Gag protein. One of the last steps in viral maturation is the enzymatic cleavage of capsid from SP1 by the viral protease. Vivecon is believed to inhibit this cleavage step by binding with the capsid-SP1 junction in Gag, leading to inhibition in development of the viral core. It does not inhibit HIV protease itself. Vivecon is the first Myriad anti-viral drug candidate, among several in development, to advance into human clinical trials. Myriad's anti-viral drug discovery program began with the discovery of the interaction between the HIV Gag protein and the human host protein, TSG101, in the viral budding/maturation pathway of HIV. This research was published in the October 5, 2001 issue of the scientific journal CELL, where it was featured as the cover article. Myriad scientists have made subsequent discoveries regarding the biology of HIV viral particle maturation, viral fusion with host cells and intra-cellular events in the life cycle of HIV which has enabled Myriad to identify additional novel targets which may inhibit HIV infection.
This work resulted in the development of Vivecon, which Myriad believes is a unique viral maturation inhibitor, and MPI-451936, a novel, orally-available, small molecule fusion inhibitor against HIV virus. MPI-451936 targets viral Gp41 protein and uniquely inhibits fusion of HIV virus that utilizes the CXCR4 co-receptor, instead of the more common CCR5 co-receptor.
Vivecon has been tested extensively for anti-viral activity and safety with both in-vitro and in-vivo models, in preclinical studies. It demonstrated anti-viral activity of less than 10 nanomolar IC50 against the HIV virus, with at least a 1,000-fold therapeutic safety index. Vivecon was also shown to be active against viral strains that are resistant to the currently marketed anti-HIV drugs, including nucleoside reverse transcriptase inhibitors such as AZT■, non-nucleoside reverse transcriptase inhibitors such as Efavirenz■ and protease inhibitors such as Ritonavir■. Vivecon has also shown a well-tolerated safety profile in a variety of preclinical studies.
"We are very pleased to begin human clinical trials with this exciting new drug candidate for the treatment of AIDS," said Adrian Hobden, Ph.D., President of Myriad Pharmaceuticals, Inc. "Vivecon is an important addition to our pipeline of drug candidates in development to treat some of the most serious, costly and devastating diseases of our time. It is also the first in a series of compounds that we hope to develop for the treatment of viral diseases."
The current clinical development plan for Vivecon is designed to expedite the drug candidate through the clinical development path. The first Phase 1 trial is intended to assess the pharmacokinetics, absorption and tolerability of the compound. This trial is formatted as a single ascending dose in healthy volunteers. Assuming successful completion of Phase 1, the plan calls for the rapid initiation of a Phase 2a multiple ascending dose trial in HIV-infected individuals to evaluate safety, pharmacokinetics and Vivecon's ability to inhibit viral replication. Myriad believes this should permit Vivecon to skip the more conventional Phase 2 clinical trial and potentially move more quickly into Phase 3 studies.
According to the U.S. Centers for Disease Control and Prevention (CDC), there are approximately 1.1 million persons in the United States living with HIV/AIDS. In 2005, the estimated number of new diagnoses of AIDS in the United States and dependent areas was 41,897 per year. The estimated number of deaths in 2005 of persons with AIDS in the United States and dependent areas was 17,011. According to the United Nations UNAIDS program, over 33 million people throughout the world are living with HIV/AIDS, and over 22 million people have died from the disease. Some 2.5 million people were newly infected with the virus in 2007, or 6,800 new infections every day.
While the widespread availability of antiretroviral and other drugs in North America has helped the number of AIDS-related deaths there to remain relatively low, the challenge has become managing these patients, due to the increase in viral resistance to the current classes of drugs. There is a strong need for drugs that can stop the resistant virus from spreading.
About Myriad
Myriad Genetics, Inc. is a biotechnology company focused on the development and marketing of novel therapeutic and molecular diagnostic products. Myriad's news and other information are available on the Company's Web site at Flurizan, Azixa and Vivecon are trademarks of Myriad Genetics, Inc. in the United States and other countries.
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