ImClone Systems Inc. is expanding Phase I trials of its BEC-2therapeutic vaccine to treat malignant melanoma, the companysaid Monday.

The new protocol includes earlier-stage patients, as well aspatients who have developed human anti-mouse antibodies(HAMA) as a result of previous cancer therapies usingmonoclonal antibodies. The original protocol enrolled stage 4patients, who have a heavy tumor load. Stage 3 patients havehad tumors excised and have an 80 percent chance ofrecurrence of the tumor within a year.

ImClone hopes that BEC-2, when administered after surgicalremoval of tumors, may stimulate the immune system toprevent or delay the onset of recurrent primary tumors ormetastases.

The drug is a monoclonal anti-idiotypic antibody that mimics aglycolipid structure, GD3, found on the surface of certain cancercells. Anti-ids are useful when the antigen being mimickeddoesn't naturally elicit a sufficient immune response or can't beproduced in quantity. GD3 fits both those criteria.

The New York company has always intended to add earlier-stage patients, said Brooks Boveroux, chief financial officer. "Wewant earlier-stage patients without the heavy tumor load toget a better idea of responses at various dosages," he said.

Safety data to date shows no visible side effects, the companysaid. The trial began in November.

ImClone shares (NASDAQ:IMCL) closed unchanged at $17.75. --Karen Bernstein

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