ImClone Systems Inc. of New York said it has signed anagreement with E. Merck of Germany for the research,development and commercialization of anti-idiotypic antibodiesand recombinant antigens for melanoma therapy.

ImClone will receive more than $10 million from Merck overfour years, said Samuel Waksal, ImClone's president. Itreceived an initial payment of "some millions" from Merckwhen the agreement was signed in December, Waksal said.

Merck received sole marketing rights to the products forEurope, Australia and New Zealand. ImClone is to get licensingfees, research support and royalties on Merck's sales of relatedproducts. ImClone retained rights in the United States and willseek a marketing partner for the Far East.

Antibodies are proteins produced by white blood cells thatbind to foreign molecules, or antigens. The specific antigen-binding sites on antibodies are called idiotypes. Researcherscan create antibodies to antibodies, or anti-idiotype antibodies.These "anti-ids" mimic the original antigen by binding to thesame antibody site as the original antigen.

ImClone has developed an anti-id antibody that mimics theGD3 glycolipid found on the surface of melanoma cells, Waksalsaid. ImClone said it believes that the GD3 glycolipid is thecrucial antigen in melanoma. ImClone's antibody fools theimmune system into producing an immune response to thecancer.

Tricking the immune system is necessary because it often failsto react to cancer cells, which can grow so slowly that theimmune system develops a tolerance to them. Also, the antigenmay not be presented to the immune system in a way thatenables the immune system to recognize it as foreign. Anti-idseither break this tolerance or bypass the presentation problem,Waksal said.

Phase I clinical trials of Imclone's product against melanomaare set to start July 1 at New York's Memorial Sloan KetteringCancer Center.

Already under way are Phase III clinical trials of anti-idproducts developed by Idec Pharmaceuticals Corp. of La Jolla,Calif., against B-cell lymphoma and Phase I clinicals onmelanoma, said William Rastetter, Idec's president. No data hasbeen released. -- Karen Bernstein

(c) 1997 American Health Consultants. All rights reserved.