Hybritech plans exit from MoAb imaging arena

One of the pioneers in monoclonal antibody research has droppedout of the in vivo imaging market. Hybritech of San Diego is phasingout the development of its Hybri-CEAker product, which was beingdeveloped to image colorectal cancer.

Hybritech's board of directors voted last month to discontinuethe company's discovery and development efforts in radioimmunotherapyand in vivo imaging. The projects are to be terminated by year-end.

Also last month, Hybritech's parent company, Eli Lilly of Indianapolis,IN, announced plans to cut 4000 salaried and contract jobs throughearly retirements and reassignments. The move reportedly is partof a broad reexamination by Lilly of its business pursuits.

Hybritech staff refused comment on whether the decision byHybritech to exit the in vivo market was part of this reexamination,referring inquiries to the parent company. It was learned, however,that the decision to exit the imaging market was precipitatedby Hybritech's electing to abandon cancer therapeutics.

Donald W. Grimm, Hybritech chairman, said in a prepared statementthat management was no longer able to justify the continued financialinvestment in cancer therapeutics.

"Without a commitment to therapeutic research, a continuedinvestment in imaging, particularly to create the infrastructurenecessary to build an imaging business, cannot be sustained,"he said.

Hybritech, like many imaging agent developers, had been pursuingthe matched-pair approach, in which a delivery system, such asa monoclonal antibody or peptide, is matched to one isotope forimaging and another for therapy. Economies of scale in developmentand marketing for the imaging and therapy markets increase thevalue of the effort.

"But when it was no longer in its strategic directionto pursue in vivo therapeutics, that set off kind of a chain reaction,in which the investment needed to (continue pursuing) the in vivoimaging product was too high," said David Pomfret, a spokespersonfor Eli Lilly.

The decision to abandon radioimmune therapy and in vivo imagingcomes at a time when the business potential for targeted imagingagents, such as monoclonal antibodies and peptides, appears onthe verge of being realized. One agent, OncoScint from Cytogenof Princeton, NJ, is on the market and others are expected soon.

Hybri-CEAker, which targets the carcinoembryonic antigen (CEA),although promising, has been in the Food and Drug Administrationreview process since 1989 and shows no signs of being clearedfor market in the near future. As Hybritech concludes its in vivoimaging and therapeutics efforts, it is actively searching forcompanies interested in licensing the technology.