Over the past several decades, much progress has been made in the area of targeted therapy where a carrier molecule selectively seeks out cancerous tissue. Rather than affecting all cells, normal and abnormal, targeted therapy can be directed at specific cells.

A variety of carrier molecules, such as cell specific antibodies, hormones, drugs, signal transmitters and metabolites, have be tested in animal models and in the clinical setting for selective targeting. Since the turn of the century, at least three drugs which are antibody-based have received FDA clearance and are available to treatment mainly blood borne diseases, such as non-Hodgkins B-lymphoma. These include the drugs Rituxan, which is a biologically active cell surface antibody delivered as a native antibody and is rapidly becoming frontline therapy for low-grade lymphoma.

Also approved are Zevelin and Bexxar, both of which are radiolabeled antibodies that selectively bring a potentially lethal dose of radiation to cancer cells through a localized radionuclide. Currently, there are several hundred clinical trials conducted world wide for virtually every type of blood borne and solid tumors using radiolabeled antibody targeted therapy.

At University Hospitals, there are several outstanding efforts in this area including:

• Original discovery of a biologically active antibody, labeled 3F8, which specifically targeted neuroblastoma and carried an I-131 therapy payload.
• The availability of radiolabeled antibodies or targeting agents which are in use or are proposed:

1. As a diagnostic imaged-guided scanning agent labeled with In-111 to direct external beam boost therapy to prostate cancer
2. For the treatment of low-grade lymphoma treatment (3 agents)
3. In support of a multi-centered clinical trial for the treatment of glioblastoma through the direct infusion of an antibody into the tumor bed by the placement of catheter in the brain to deliver the agent
4. For Ho-166 therapy used as a preparative regime for bone marrow transplant for patients with multiple myeloma

• The establishment of a core laboratory to evaluate multi–centered dosimetric information for patients treated with radiolabeled antibodies.