* Cytogen Corp., of Princeton, N.J., signed a letter of intent for the sale of its manufacturing plant. Negotiations are in late-stage discussions, with closure expected soon. Under the proposed agreement, Cytogen will receive an up-front cash payment and would continue to have its ProstaScint and OncoScint products manufactured there for a defined time.

* Guilford Pharmaceuticals Inc., of Baltimore, reported that the Gliadel Wafer, the company's treatment for malignant brain cancer, received regulatory approval from the Canadian Health Protection Branch, and marketing authorization from the French Drug Agency, for use in the treatment of glioblastoma multiforme, a common and rapidly fatal form of malignant brain cancer. Gliadel is a biodegradable polymer wafer that is implanted in the cavity created when a brain tumor is surgically removed. There the wafer releases carmustine, a chemotherapeutic drug, directly to the site. Rhone-Poulenc SA, of Paris, through its subsidiary Rhone-Poulenc Rorer Inc. (RPR), of Collegeville, Pa., has a deal with Guilford, under which Guilford Pharmaceuticals Inc. will receive $2 million as a milestone payment from RPR, upon approval of Gliadel for marketing in Canada.

* Human Genome Sciences Inc. (HGS), of Rockville, Md., received clearance from the FDA to start Phase I/II studies of vascular endothelial growth factor-2 for patients suffering from critical limb ischemia. HGS is collaborating on the product with Vascular Genetics Inc., of Research Triangle Park, N.C. HGS owns 33.9 percent of Vascular Genetics. (See BioWorld Today, Nov. 16, 1998, p. 4.)

* Immunomedics Inc., of Morris Plains, N.J., said the FDA granted orphan drug designation to its CEA-Cide cancer therapeutic for pancreatic cancer. CEA-Cide is a humanized monoclonal antibody against the carcinoembryonic antigen, which is expressed in several solid tumors.

* Medarex Inc., of Annandale, N.J., will expand its collaboration with Merck KgaA, of Darmastadt, Germany, for the anticancer bispecific antibody MDX-4476. Merck paid a $1.5 million fee for the exclusive option to negotiate for worldwide licensing rights, with Medarex retaining U.S. rights, and agreed to pay for Phase II trials. MDX-447 is a bispecific antibody that targets the epidermal growth factor receptor, which is overexpressed in many solid tumors.

* Progenitor Inc., of Menlo Park, Calif., requested a voluntary delisting of its common stock and warrants from the Nasdaq stock exchange, effective Dec. 23. As a result of the voluntary delisting, the company's common stock will be eligible for quotation on the OTC Bulletin Board or the National Quotation Bureau's Pink Sheets, beginning Dec. 24. The company took this action in response to the indefinite trading halt in both its common stock (NASDAQ:PGEN) and warrants (PGENW) by Nasdaq Dec. 18. (See BioWorld Today, Dec. 19, 1998, p. 1.)

* Sugen Inc., of South San Francisco, filed an investigational new drug application with the FDA for the clinical testing of SU6668 with oral and IV formulations. SU6668 potentially offers multiple mechanism of action for the treatment of cancer in a single agent, by selectively targeting the receptors for Flk-1/KDR, platelet derived growth factor, and fibroblast growth factor. The first Phase I trial will take place at the University of California, Los Angeles Medical Center, in the first quarter of 1999 in patients with advanced solid tumors.