Cytogen leaps hurdles with progress in Europe

The regulatory logjam delaying commercialization of monoclonalantibody imaging agents is beginning to disintegrate. Cytogenof Princeton, NJ, has received the first approvals in Europe forcancer-imaging monoclonals.

The European approvals should provide the boost for this newimaging technology that the field of nuclear medicine has beenawaiting. Monoclonal antibody agents expand the clinical utilityof nuclear imaging by providing a method of targeting specificsites with radiotracers.

Cytogen obtained market approval this month in the U.K. andHolland for OncoScint CR103, a monoclonal-antibody-based imagingagent for colorectal cancer. The latest national approvals forOncoScint follow initial positive rulings last month in Germanyand Luxembourg.

Cytogen received a recommendation of approval for the agentfrom the Committee for Proprietary Medicinal Products (CPMP) ofthe European Community in June (SCAN 7/3/91).

OncoScint is the first monoclonal antibody cancer imaging agentto receive EC national approvals. Centocor started selling itsmyocardial infarction agent, Myoscint, in Europe in 1989. EuroCetuswill sell OncoScint for Cytogen in Europe. No monoclonal-basedimaging agents have been approved in the U.S.

"This is the first new product of its type to enter practice,"said Thomas J. McKearn, Cytogen president. "We think it willallow the nuclear medicine physician to become an integral partof the decision-making team for colon cancer patients."

Cytogen's clinical work has shown that nuclear scans usingthe colorectal-cancer-targeted agent are often able to detectdisease not seen on CT or MRI scans. The nuclear imaging techniqueis particularly useful when trying to determine if colon cancerhas recurred after an operation, McKearn said.

"The patient may start developing a rising serum markerbut have no clear-cut evidence of (colon cancer) recurrence onany of the anatomic scanning methods," he said. "Determiningif (anatomic) change is in fact recurrence of malignancy is difficult.So the antibody-based scan has been particularly useful in thissetting."

Cytogen will have a window of opportunity to sell the imagingagent before other companies--such as Hybritech and Immunomedicsin the U.S.--receive approvals for their colorectal agents. Thefour EC countries that have approved the agent account for 60%of the colorectal cancer market in Europe, McKearn said.

OncoScint has also been tested for use in targeting ovariancancer, although the company did not include those results inits original application to the CPMP. An amendment seeking approvalof the agent for ovarian cancer applications should be filed withthe CPMP in the next few months, he said.

Applications for market approval of OncoScint in both colorectaland ovarian indications have been on file with the Food and DrugAdministration for about two years. Cytogen hopes to obtain favorableFDA action on these applications "in the relatively nearfuture," McKearn said.

The company is about to enter phase three trials at the FDAwith a prostate cancer agent. Trials for lung and breast imagingagents are in initial stages.

"We have agents under study now that cover about 55% ofthe approximately 1.1 million new cases of cancer that will bediagnosed in the U.S. this year," he said.

About 160,000 new cases of colorectal cancer are discoveredeach year in this country. When monitoring for recurrence of thedisease is factored in, the number of colorectal cases is threeor four times the incidence figure, he said.

Cytogen will co-market OncoScint in the U.S. with Knoll Pharmaceuticalof Whippany, NJ. Knoll is the U.S. subsidiary of Knoll AG of Germany,which in turn is owned by BASF AG (SCAN 5/22/91).

While EuroCetus will work alone in Europe to expand approvalsand sell the product, Cytogen is gearing up for an active rolein U.S. sales once FDA approval is obtained, McKearn said.

McKearn, who helped found the biotechnology company in 1981,was promoted in September from senior vice president for scientificaffairs to president. He serves under chairman and CEO GeorgeW. Ebright.

In addition to his past supervision of basic research, clinicalwork, regulatory affairs and manufacturing, McKearn will haveauthority over sales and marketing as well as finance. His expansionin personal responsibilities parallels the company's gearing-upprocess as commercialization becomes a reality, McKearn said.

"The two functions that have to become fully operationalwithin the next year are sales and marketing and manufacturing,"he said.

BRIEFLY NOTED:

• Molecular Biosystems' Japanese marketing partner, Shionogi& Co. of Osaka, has filed a New Drug Application in Japanfor Albunex, MBI's cardiac perfusion ultrasound contrast agent.The filing is a necessary milestone for the San Diego contrastdeveloper to receive a $4 million payment under its developmentagreement with Shionogi. Review of Albunex by the Japanese Ministryof Health may take up to two years, MBI said.