Cytogen Corporation Receives Patent Covering Oral Drug Delivery Agents

PRINCETON, N.J., Nov. 27 /PRNewswire-FirstCall/ -- Cytogen Corporation today announced that it has been issued United States patent number 7,135,457 covering its oral drug delivery agents - random peptide compositions that bind to gastro-intestinal tract (GIT) transport receptors.

The patent specifically covers compositions of Cytogen's oral delivery agents that are capable of facilitating transport of an active agent through a human or animal gastro-intestinal tract (GIT), and derivatives and analogs thereof, and nucleotide sequences coding for said proteins and derivatives. The oral delivery agents have use in facilitating transport of active agents from the lumenal side of the GIT into the systemic blood system, and/or in targeting active agents to the GIT.

By binding (covalently or noncovalently) one of Cytogen's delivery agents to an orally administered drug or by coating the surface of nanoparticles or liposomes with the delivery agent, the drug can be targeted to specific receptor sites or transport pathways which are known to operate in the human gastrointestinal tract, thus facilitating its systemic absorption into the bloodstream.

The binding of Cytogen's delivery agents to these receptors has been confirmed in preclinical models, and successful in vivo delivery of both insulin and leuprolide in animal models have been demonstrated. Based on these results, the Company is seeking partnerships for oral drug delivery.

"Cytogen's proprietary technology may represent an important advancement for patients with a variety of disorders who can greatly benefit from the availability of an oral dosing option," said Vernon Alvarez, Ph.D., listed inventor on the patent and currently a consultant to Cytogen. "Through future collaborations, we look forward to the development of products for oral administration that, until now, could only be administered by injection."

Dr. Alvarez is responsible for advancing Cytogen's oral delivery technology and other technology resulting from the Company's proprietary phase display platform. Dr. Alvarez has over 18 years of biotechnology and R&D experience in antibodies, peptides, immunotherapeutics, radiopharmaceuticals, and novel drug delivery technologies. He was formerly employed by Cytogen where he held various positions, including vice president of discovery research and vice president of drug discovery. He was a primary contributor to the successful development of several of Cytogen's commercialized products.

For more information, a white paper titled "Active-transport peptides induce GIT transport of nanoparticles containing leuprolide and insulin in an in vivo rat model" is available under the Licensing Opportunities section of Cytogen's website.

About Oral Drug Delivery

The common routes of therapeutic drug administration are oral ingestion or parenteral (intravenous, subcutaneous and intramuscular) routes of administration. Intravenous drug administration suffers from numerous limitations, including (i) the risk of adverse effects resulting from rapid accumulation of high concentrations of drug, (ii) repeated injections which can cause patient discomfort; and (iii) the risk of infection at the site of repeated injections. Subcutaneous injection is not generally suitable for delivering large volumes or for irritating substances. Whereas oral administration is generally more convenient, it is limited where the therapeutic agent is either unstable in the harsh intestinal environment or not efficiently absorbed by the gastrointestinal tract, or both. To date, the development of oral formulations for the effective delivery of peptides, proteins and macromolecules has been an elusive target. Poor membrane permeability; enzymatic instability, large molecular size, and hydrophilic properties are four factors that have remained major hurdles for peptide and protein formulations. In order to develop an efficacious oral formulation, the peptide must be protected from the enzymatic environment of the GIT, presented to the absorptive epithelial barrier in a sufficient concentration to effect transcellular flux, and if possible "smuggled" across the epithelial barrier in an apical to basolateral direction.

Cytogen's technology is unique in that it is based on proprietary peptides that facilitate the transport of macromolecules across membranes while preserving the structure and biological effects of the drug as well as the integrity of the intestinal membrane. Additionally, the technology is broadly applicable to several different types of drugs, including proteins, small charged molecules, and carbohydrates.

ABOUT CYTOGEN CORPORATION

Founded in 1980, Cytogen is a biopharmaceutical company dedicated to advancing the care of cancer patients by building, developing, and commercializing a portfolio of specialty pharmaceutical products. The Company's specialized sales force currently markets QUADRAMET(R), PROSTASCINT(R), and SOLTAMOX(TM) to the U.S. oncology market. QUADRAMET is approved for the treatment of pain in patients whose cancer has spread to the bone, PROSTASCINT is a PSMA-targeting monoclonal antibody-based agent to image the extent and spread of prostate cancer, and SOLTAMOX is the first liquid hormonal therapy approved in the U.S. for the treatment of breast cancer in adjuvant and metastatic settings. In early 2007, Cytogen plans to introduce its fourth approved oncology product to the U.S. market, CAPHOSOL(R), a prescription medical device for the treatment of oral mucositis and dry mouth. The Company is also developing CYT-500, a third-generation radiolabeled antibody to treat prostate cancer. Cytogen's product-focused strategy focuses on attaining sustainable growth through clinical, commercial, and strategic initiatives.

A copy of the full prescribing information for CAPHOSOL, QUADRAMET, PROSTASCINT, and SOLTAMOX, including box warnings, may be obtained in the U.S. from Cytogen Corporation by calling toll free 800-833-3533 or by visiting Cytogen's web site at www.cytogen.com. The Company's website is not part of this press release.

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 successfully marketing SOLTAMOX and CAPHOSOL; 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. All information in this press release, including 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 this information to reflect subsequent events or circumstances.

CONTACT: Susan Mesco of Cytogen Corporation, +1-609-750-8213

Web site: http://www.cytogen.com//