Prostate-specific Membrane Antigen Emerging as an Important Therapeutic Target to Deal with Prostate Cancer
Jun 21, 2005, 10:50, Reviewed by: Dr.
|"PSMA is emerging as an important therapeutic target because of its strong expression on prostate cancer and tumor vasculature and its limited presence on normal tissues, making it ideal for use as an ADC therapy."
Seattle Genetics, Inc. (Nasdaq:SGEN) and PSMA Development Company LLC (PDC), a joint venture between Progenics Pharmaceuticals, Inc. (Nasdaq:PGNX) and Cytogen Corporation (Nasdaq:CYTO), announced today that Seattle Genetics has licensed its proprietary antibody-drug conjugate (ADC) technology to PDC.
The license provides PDC with rights to utilize the ADC technology to link cell-killing drug payloads to PDC's fully human monoclonal antibodies that target prostate-specific membrane antigen (PSMA), which is highly expressed on both primary and metastatic prostate cancer cells.
"PSMA is emerging as an important therapeutic target because of its strong expression on prostate cancer and tumor vasculature and its limited presence on normal tissues, making it ideal for use as an ADC therapy," commented Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. "Our industry-leading ADC technology can link synthetic, cell-killing auristatin payloads to the PSMA-targeted antibodies developed by PDC, resulting in compounds that are designed to be more potent and effective in treating prostate cancer."
PSMA is a protein abundantly expressed on the surface of prostate cancer cells, with an increased expression in high-grade cancers, metastatic disease and hormone-refractory prostate cancer. PSMA is also present at high levels on the newly formed blood vessels, or neovasculature, needed for the growth and survival of many solid tumors. In contrast to other prostate-related antigens such as prostate-specific antigen (PSA), prostatic acid phosphatase (PAP) and prostate secretory protein, PSMA is a membrane glycoprotein that is not secreted. This unique expression pattern makes PSMA an excellent antigenic target for monoclonal antibody diagnostic and therapeutic options.
"We are encouraged by preclinical data demonstrating that PSMA can be effectively targeted by antibodies developed through PDC in combination with Seattle Genetics' ADC technology," said Michael D. Becker, Cytogen's President and Chief Executive Officer. "In addition to major ADC collaborations and licenses, Seattle Genetics has itself demonstrated the potential of this technology by advancing multiple ADC compounds into development. As we continue to advance PSMA programs through preclinical development and initiate clinical trials for our first fully human monoclonal antibody, we are building important clinical momentum which will set the stage for additional drugs coming from our unique PSMA technologies."
Under the terms of the multi-year agreement, PDC will pay Seattle Genetics a $2.0 million upfront fee for access to the technology for use with antibodies targeting the PSMA antigen. PDC has also agreed to make progress-dependent milestone payments and pay royalties on net sales of resulting ADC products. PDC is responsible for research, product development, manufacturing and commercialization of all products under the collaboration. Seattle Genetics will receive material supply and annual maintenance fees as well as research support payments for any assistance provided to PDC in developing ADC products.
ADCs utilize the targeting ability of monoclonal antibodies to deliver potent, cell-killing payloads to specific cells. Seattle Genetics has developed improved ADC technology employing synthetic, highly potent drugs that can be attached to antibodies through proprietary linker systems. The linkers are stable in the bloodstream and release the drug payload once inside target cells. ADCs can increase the therapeutic potential of the many antibodies with targeting ability but limited or no inherent cell-killing activity.
About Prostate Cancer
Prostate cancer is the most common type of cancer found in American men, other than skin cancer. The American Cancer Society estimates that there will be about 232,090 new cases of prostate cancer in the United States in the year 2005 and that about 30,350 men will die of this disease. Prostate cancer is the second leading cause of cancer death in men, exceeded only by lung cancer.
- PSMA Development Company LLC
About Seattle Genetics
Seattle Genetics is a biotechnology company focused on the development of monoclonal antibody-based therapies for the treatment of cancer and immunologic diseases. The company is conducting clinical and preclinical development of a diverse portfolio of product candidates in a variety of oncology and immunology settings. In addition, Seattle Genetics has developed proprietary antibody-drug conjugate (ADC) technology comprised of highly potent synthetic drugs and stable linkers for attaching the drugs to monoclonal antibodies. The company currently has license agreements for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including Genentech, Bayer, CuraGen and MedImmune. More information about Seattle Genetics' pipeline and technologies can be found at www.seattlegenetics.com.
About Cytogen Corporation
Founded in 1980, Cytogen Corporation of Princeton, NJ is a product-driven biopharmaceutical company that develops and commercializes innovative molecules that can be used to build leading franchises. Cytogen's marketed products include QUADRAMET(R) (samarium Sm-153 lexidronam injection) and PROSTASCINT(R) (capromab pendetide) kit for the preparation of Indium In-111 capromab pendetide in the United States. Cytogen also has exclusive United States marketing rights to COMBIDEX(R) (ferumoxtran-10) for all applications, and the exclusive right to market and sell ferumoxytol (previously Code 7228) for oncology applications in the United States. Cytogen's development pipeline consists of therapeutics targeting prostate-specific membrane antigen (PSMA), a protein highly expressed on the surface of prostate cancer cells and the neovasculature of solid tumors. Full prescribing information for Cytogen's products is available at http://www.cytogen.com or by calling 1-800-833-3533. For more information, please visit Cytogen's website at http://www.cytogen.com, which is not part of this press release.
About Progenics Pharmaceuticals, Inc.
Progenics Pharmaceuticals, Inc., of Tarrytown, N.Y. is a biopharmaceutical company focusing on the development and commercialization of innovative therapeutic products to treat the unmet medical needs of patients with debilitating conditions and life-threatening diseases. The Company's principal programs are directed toward symptom management and supportive care and the treatment of HIV infection and cancer. The Company has five product candidates in clinical development and several others in preclinical development. In symptom management and supportive care, the Company is developing methylnaltrexone (MNTX) to treat the constipation associated with opioid-based pain relievers without interfering with pain relief. MNTX is in pivotal phase 3 clinical testing for treatment of opioid-induced constipation in patients with advanced medical illness. MNTX is also being studied for the management of patients with post-operative bowel dysfunction and relief of opioid-induced constipation in patients with chronic pain. In the area of HIV infection, the Company is developing viral-entry inhibitors, including PRO 140, a humanized monoclonal antibody targeting the HIV coreceptor CCR5 (in phase 1 studies), and PRO 542, a genetically engineered molecule designed to neutralize HIV (in phase 2 studies). In addition, the Company is conducting research on ProVax, a novel prophylactic HIV vaccine. The Company, in collaboration with Cytogen Corporation, is developing immunotherapies for prostate cancer, including a human monoclonal antibody directed against prostate-specific membrane antigen (PSMA), a protein found on the surface of prostate cancer cells. The Company is also developing vaccines designed to stimulate an immune response to PSMA. A recombinant PSMA vaccine is in phase 1 clinical testing. The Company is also developing a cancer vaccine, GMK, in phase 3 clinical trials for the treatment of malignant melanoma. For more information, please visit our website at www.progenics.com.
For Seattle Genetics:
Certain of the statements made in this press release are forward-looking, such as those, among others, relating to the therapeutic potential of products utilizing Seattle Genetics' ADC technology. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include risks related to adverse clinical results as our product candidates move into and advance in clinical trials, risks inherent in early stage development and failure by Seattle Genetics to secure or maintain relationships with collaborators. More information about the risks and uncertainties faced by Seattle Genetics is contained in the Company's filings with the Securities and Exchange Commission. Seattle Genetics disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.
This press release contains certain "forward-looking" statements within the meaning of the Private Securities Litigation Reform Act of 1995 and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical facts, included in this press release regarding our strategy, future operations, financial position, future revenues, projected costs, prospects, plans and objectives of management are forward-looking statements. Such forward-looking statements involve a number of risks and uncertainties and investors are cautioned not to put any undue reliance on any forward-looking statement. There are a number of important factors that could cause Cytogen's results to differ materially from those indicated by such forward-looking statements. In particular, Cytogen's business is subject to a number of significant risks, which include, but are not limited to: the risk of obtaining the necessary regulatory approvals; the risk of whether products result from development activities; the risk of shifts in the regulatory environment affecting sales of Cytogen's products such as third-party payor reimbursement issues; the risk associated with Cytogen's dependence on its partners for development of certain projects, as well as other factors expressed from time to time in Cytogen's periodic filings with the Securities and Exchange Commission (the "SEC"). As a result, this press release should be read in conjunction with Cytogen's periodic filings with the SEC. The forward-looking statements contained herein are made only as of the date of this press release, and Cytogen undertakes no obligation to publicly update such forward-looking statements to reflect subsequent events or circumstances.
The information contained in this document is current as of June 20, 2005. 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, it is 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 or proceed as planned, the risks and uncertainties associated with dependence upon the actions of our corporate, academic and other collaborators and of government regulatory agencies, the risk that our licenses to intellectual property may be terminated because of our failure to have satisfied performance milestones, the risk that products that appear promising in early clinical trials do not demonstrate efficacy in larger-scale clinical trials, the risk that we may not be able to manufacture commercial quantities of our products, 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, 2004 and Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2005 and other reports filed with the Securities and Exchange Commission, to which investors are referred for further information. In particular, the Company cannot assure you that any of its programs will result in a commercial product.
Progenics does not have a policy of updating or revising forward-looking statements and assumes no obligation to update any forward-looking statements contained in this document as a result of new information or future events or developments. 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.
Contact Seattle Genetics Peggy Pinkston, 425-527-4160 [email protected] or Cytogen Corporation Jonathan Fassberg of The Trout Group 212-477-9077 ext. 16 [email protected] or Progenics Pharmaceuticals Richard W. Krawiec, Ph.D., 914-789-2800 [email protected]
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