Progenics Pharmaceuticals' Published Study Describes Benefits of Combining Two Investigational Drugs to Block HIV Infection

- Progenics' Viral-entry Inhibitor Synergistic with

Trimeris/Roche Compound in Vitro -



Apr 05, 2001, 01:00 ET from Progenics Pharmaceuticals, Inc.

    TARRYTOWN, N.Y., April 5 /PRNewswire/ --
 Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX) announced the publication of a
 scientific article showing that the investigational drugs PRO 542 and T-20
 significantly enhanced anti-HIV activity when used in combination in
 laboratory studies.  Progenics' scientists and researchers at the Albert
 Einstein College of Medicine reported that the combination of the two
 compounds potently blocked HIV entry into cells. The activity of each agent
 was enhanced by the presence of the other, resulting in synergistic or
 supra-additive antiviral effects.  Progenics is developing PRO 542, and
 Trimeris, Inc. (Nasdaq: TRMS) and its partner F. Hoffmann-La Roche Ltd are
 developing T-20. The article appears in the current issue of the Journal of
 Infectious Diseases (volume 183, issue 7).
     "The 15 currently approved anti-HIV drugs all target viral enzymes that
 the virus uses for replication after it has infected a cell," explained
 William C. Olson, Ph.D., Vice President of Research and Development at
 Progenics and senior author of the paper, "but unlike other agents, PRO 542
 and T-20 are designed to block the virus prior to infection. When combined in
 vitro, these compounds demonstrated potent synergy against diverse viral
 isolates, a result that is important for combination use of these agents in
 patients.  Our findings further predict that synergies may be observed for
 combinations that include other entry inhibitors, such as Progenics' PRO 140."
     "The unusually strong synergy observed between PRO 542 and T-20 bodes well
 for development of powerful combination therapies to block HIV infection by
 preventing its entry into the cell," said Dani P. Bolognesi, Ph.D., Chief
 Executive Officer of Trimeris. "Furthermore, the combination of entry
 inhibitors with existing therapies that target virus replication within the
 cell, would provide a one-two punch that should translate into significant
 benefits for HIV infected patients."
     HIV infection is a multi-step process that affords various promising
 targets for therapy.  First, the virus attaches to a receptor on surface of
 the host cell. This complex then interacts with a coreceptor, and finally
 fusion with the cell membrane occurs, thus allowing the virus to infect the
 cell. By commandeering the cell's reproductive machinery, the virus creates
 thousand of copies of itself which are then released from the host and may
 infect new cells.
     Progenics' PRO 542 is currently in Phase II clinical trials and Trimeris'
 lead product candidate, T-20, which inhibits fusion of HIV with host cells, is
 currently in Phase III clinical trials.  PRO 542 directly neutralizes HIV,
 thereby preventing the attachment of the viral surface envelope glycoprotein
 gp120 to CD4, the primary receptor for HIV.  PRO 542 is a hybrid protein that
 incorporates four HIV binding regions of CD4 into a human antibody-like
 molecule.
 
     Progenics Pharmaceuticals, Inc., is a biopharmaceutical company focusing
 on the development and commercialization of products for the treatment and
 prevention of viral, cancer, and other life-threatening diseases. The Company
 applies its immunological expertise to develop biopharmaceuticals to fight
 viral diseases, such as human immunodeficiency virus (HIV) infections, and
 cancers, such as malignant melanoma and prostate cancer.  The Company has
 initiated Phase II clinical trials of its lead HIV product, PRO 542, a
 viral-entry inhibitor.  The Company is developing follow-on product candidates
 in HIV infection: PRO 367 has completed a Phase I study, PRO 140 is preparing
 to commence Phase I/II trials, and a lead therapeutic candidate has been
 selected from a novel class of anti-HIV compounds known as sulfated CCR5
 peptides.  The Company is also engaged in programs to discover and develop
 small-molecule HIV therapeutics that target the fusion co-receptors of the
 virus and other programs focusing on HIV attachment and fusion. The Company is
 developing cancer immunotherapies based on PSMA (prostate specific membrane
 antigen) technology.  The Company's most clinically advanced product, GMK, is
 a cancer vaccine in a pivotal Phase III clinical trial for the treatment of
 malignant melanoma.  Progenics is also prepared to commence Phase II trials
 with a second cancer vaccine, MGV, with broad application to a variety of
 cancers. The Company is also developing a novel small-molecule antioxidant,
 dehydroascorbic acid (DHA), to treat stroke and other disorders.
 
     This press release contains forward-looking statements. Any statements
 contained herein that are not statements of historical fact may be
 forward-looking statements. When the Company uses the words "anticipates,"
 "plans," "expects" and similar expressions they are identifying
 forward-looking statements. Such forward-looking statements involve risks and
 uncertainties which may cause the Company's actual results, performance or
 achievements to be materially different from those expressed or implied by
 forward-looking statements. Such factors include, among others, the
 uncertainties associated with product development, the risk that clinical
 trials will not commence when or proceed as planned, the risks and
 uncertainties associated with dependence upon the actions of the Company's
 corporate, academic and other collaborators and of government regulatory
 agencies, the risk that products that appear promising in early clinical
 trials do not demonstrate efficacy in larger-scale clinical trials, the
 uncertainty of future profitability and other factors set forth more fully in
 the Company's Annual Report on Form 10-K for the fiscal year ended December
 31, 2000 and other periodic filings with the Securities and Exchange
 Commission to which investors are referred for further information. In
 particular, the Company cannot assure you that any of the their programs will
 result in a commercial product. The Company does not have a policy of updating
 or revising forward-looking statements, and thus it should not be assumed that
 the Company's silence over time means that actual events are bearing out as
 expressed or implied in such forward-looking statements.
 
     Editor's Note:
     Additional information Progenics Pharmaceuticals is available at
 http://www.progenics.com.
     This release is available on the Internet at http://www.noonanrusso.com.
 
 

SOURCE Progenics Pharmaceuticals, Inc.
    TARRYTOWN, N.Y., April 5 /PRNewswire/ --
 Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX) announced the publication of a
 scientific article showing that the investigational drugs PRO 542 and T-20
 significantly enhanced anti-HIV activity when used in combination in
 laboratory studies.  Progenics' scientists and researchers at the Albert
 Einstein College of Medicine reported that the combination of the two
 compounds potently blocked HIV entry into cells. The activity of each agent
 was enhanced by the presence of the other, resulting in synergistic or
 supra-additive antiviral effects.  Progenics is developing PRO 542, and
 Trimeris, Inc. (Nasdaq: TRMS) and its partner F. Hoffmann-La Roche Ltd are
 developing T-20. The article appears in the current issue of the Journal of
 Infectious Diseases (volume 183, issue 7).
     "The 15 currently approved anti-HIV drugs all target viral enzymes that
 the virus uses for replication after it has infected a cell," explained
 William C. Olson, Ph.D., Vice President of Research and Development at
 Progenics and senior author of the paper, "but unlike other agents, PRO 542
 and T-20 are designed to block the virus prior to infection. When combined in
 vitro, these compounds demonstrated potent synergy against diverse viral
 isolates, a result that is important for combination use of these agents in
 patients.  Our findings further predict that synergies may be observed for
 combinations that include other entry inhibitors, such as Progenics' PRO 140."
     "The unusually strong synergy observed between PRO 542 and T-20 bodes well
 for development of powerful combination therapies to block HIV infection by
 preventing its entry into the cell," said Dani P. Bolognesi, Ph.D., Chief
 Executive Officer of Trimeris. "Furthermore, the combination of entry
 inhibitors with existing therapies that target virus replication within the
 cell, would provide a one-two punch that should translate into significant
 benefits for HIV infected patients."
     HIV infection is a multi-step process that affords various promising
 targets for therapy.  First, the virus attaches to a receptor on surface of
 the host cell. This complex then interacts with a coreceptor, and finally
 fusion with the cell membrane occurs, thus allowing the virus to infect the
 cell. By commandeering the cell's reproductive machinery, the virus creates
 thousand of copies of itself which are then released from the host and may
 infect new cells.
     Progenics' PRO 542 is currently in Phase II clinical trials and Trimeris'
 lead product candidate, T-20, which inhibits fusion of HIV with host cells, is
 currently in Phase III clinical trials.  PRO 542 directly neutralizes HIV,
 thereby preventing the attachment of the viral surface envelope glycoprotein
 gp120 to CD4, the primary receptor for HIV.  PRO 542 is a hybrid protein that
 incorporates four HIV binding regions of CD4 into a human antibody-like
 molecule.
 
     Progenics Pharmaceuticals, Inc., is a biopharmaceutical company focusing
 on the development and commercialization of products for the treatment and
 prevention of viral, cancer, and other life-threatening diseases. The Company
 applies its immunological expertise to develop biopharmaceuticals to fight
 viral diseases, such as human immunodeficiency virus (HIV) infections, and
 cancers, such as malignant melanoma and prostate cancer.  The Company has
 initiated Phase II clinical trials of its lead HIV product, PRO 542, a
 viral-entry inhibitor.  The Company is developing follow-on product candidates
 in HIV infection: PRO 367 has completed a Phase I study, PRO 140 is preparing
 to commence Phase I/II trials, and a lead therapeutic candidate has been
 selected from a novel class of anti-HIV compounds known as sulfated CCR5
 peptides.  The Company is also engaged in programs to discover and develop
 small-molecule HIV therapeutics that target the fusion co-receptors of the
 virus and other programs focusing on HIV attachment and fusion. The Company is
 developing cancer immunotherapies based on PSMA (prostate specific membrane
 antigen) technology.  The Company's most clinically advanced product, GMK, is
 a cancer vaccine in a pivotal Phase III clinical trial for the treatment of
 malignant melanoma.  Progenics is also prepared to commence Phase II trials
 with a second cancer vaccine, MGV, with broad application to a variety of
 cancers. The Company is also developing a novel small-molecule antioxidant,
 dehydroascorbic acid (DHA), to treat stroke and other disorders.
 
     This press release contains forward-looking statements. Any statements
 contained herein that are not statements of historical fact may be
 forward-looking statements. When the Company uses the words "anticipates,"
 "plans," "expects" and similar expressions they are identifying
 forward-looking statements. Such forward-looking statements involve risks and
 uncertainties which may cause the Company's actual results, performance or
 achievements to be materially different from those expressed or implied by
 forward-looking statements. Such factors include, among others, the
 uncertainties associated with product development, the risk that clinical
 trials will not commence when or proceed as planned, the risks and
 uncertainties associated with dependence upon the actions of the Company's
 corporate, academic and other collaborators and of government regulatory
 agencies, the risk that products that appear promising in early clinical
 trials do not demonstrate efficacy in larger-scale clinical trials, the
 uncertainty of future profitability and other factors set forth more fully in
 the Company's Annual Report on Form 10-K for the fiscal year ended December
 31, 2000 and other periodic filings with the Securities and Exchange
 Commission to which investors are referred for further information. In
 particular, the Company cannot assure you that any of the their programs will
 result in a commercial product. The Company does not have a policy of updating
 or revising forward-looking statements, and thus it should not be assumed that
 the Company's silence over time means that actual events are bearing out as
 expressed or implied in such forward-looking statements.
 
     Editor's Note:
     Additional information Progenics Pharmaceuticals is available at
 http://www.progenics.com.
     This release is available on the Internet at http://www.noonanrusso.com.
 
 SOURCE  Progenics Pharmaceuticals, Inc.