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Biotech / Medical : progenics -- Ignore unavailable to you. Want to Upgrade?

To: keokalani'nui who wrote (58)	10/26/2001 10:51:15 AM
From: keokalani'nui	Read Replies (2) \| Respond to of 139

Progenics Enters Collaboration With Formatech to Develop Improved Dosing Formulations For Investigational HIV Drug Pro 542 - Collaboration Leverages New Efficacy Data in HIV Animal Model - SAN FRANCISCO, Oct. 26 /PRNewswire/ -- Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX - news) announced the initiation of a collaboration with Formatech, Inc., Andover, MA, to develop improved product formulations for PRO 542, an investigational drug currently in Phase II clinical testing for the treatment of HIV (human immunodeficiency virus) infection. The announcement accompanies the release of new findings that PRO 542 possesses potent antiviral activity when given by multiple routes of administration, including subcutaneous injection. The new studies demonstrated that PRO 542 reduced viral load to undetectable levels in a well-recognized animal model of HIV infection and may point the way towards simplified dosing regimens in man. The findings were presented today at the 39th Annual Meeting of the Infectious Diseases Society of America in San Francisco. ``We welcome the opportunity to work with Progenics,'' said Benjamin S. Isaacs, Ph.D., President, Formatech. ``This collaboration allows us to leverage our core expertise and past successes in developing optimized clinical formulations for this important new agent for HIV-infected individuals. Formatech is a leader in formulation science and has a proven track record in developing highly optimized dosage forms for protein therapeutics like PRO 542.'' PRO 542 belongs to a new class of drugs, viral entry inhibitors, which are intended to prevent HIV from entering and infecting cells. PRO 542 is an antibody-like molecule which is designed to neutralize HIV by directly binding to gp120, a protein on the surface of the virus, thereby preventing HIV attachment to healthy cells within the immune system. In previous Phase I/II studies in HIV-infected patients, intravenously administered PRO 542 mediated dose-dependent and statistically significant reductions in plasma HIV RNA, a measure of HIV ``viral load.'' PRO 542 is currently in Phase II clinical testing in HIV-infected adults and children. Before testing subcutaneously administered PRO 542 in patients, Progenics' scientists and their collaborators at the Scripps Research Institute, San Diego, used SCID (severe combined immunodeficiency) mice to model HIV infection. This model uses naturally occurring HIV and human immune cells to mimic human infection. PRO 542 decreased viral loads to undetectable levels (<400 copies/ml, the lower limit of detection of the assay) in all animals treated. The viral-load reductions exceeded 10-fold in certain animals. The viral levels remained at or below the detection limit throughout the course of treatment. This potent antiviral activity was seen when the animals were treated with PRO 542 by subcutaneous injection as well as by more conventional methods. ``PRO 542 has a profound effect on viral loads in this model, and was much more effective than the best available HIV-neutralizing antibodies,'' said William C. Olson, Ph.D., Progenics' Vice President of Research and Development and co-author of the presentation. ``We are encouraged by the findings that PRO 542's ability to control an established infection is not limited to a particular dosing strategy. In future studies, we plan to investigate additional approaches to simplifying therapy. PRO 542 is currently the subject of dose-ranging Phase II studies that are designed to support Phase III clinical trials.'' Progenics also announced the publication of a scientific article describing an experimental and theoretical study on the structure of PRO 542 as it binds to HIV and inactivates it. As reported in the Journal of Virology, Progenics scientists and their collaborators at Florida State University, Tallahassee, FL, used immuno electron microscopy to visualize the structure of PRO 542. They observed PRO 542, both alone and in complex with the HIV envelope glycoprotein gp120, which resides on the surface of the virus and mediates its attachment to target cells. PRO 542 was discovered to possess a remarkably extended and flexible structure that enables it to bind four molecules of gp120 at once. Using molecular modeling to complement the experimental findings, the researchers simulated the binding of PRO 542 to the gp120 spikes that stud the viral surface. The size or ``wingspan'' of PRO 542 is significantly larger than that of a naturally occurring human antibody. Therefore, the researchers concluded that PRO 542 possesses a unique ability to cross link multiple gp120 spikes. These findings provide insight into PRO 542's capability to potently neutralize wild-type strains of HIV. The article appears in the Journal of Virology (Vol. 75, No. 14), a leading peer-reviewed journal.