A phase I radioimmunolocalization trial of humanized monoclonal antibody huA33 in patients with gastric carcinoma

• Published in: Cancer science 2006-11, Vol.97 (11), p.1248-1254
• Main Authors: Sakamoto, Junichi, Oriuchi, Noboru, Mochiki, Erito, Asao, Takayuki, Scott, Andrew M., Hoffman, Eric W., Jungbluth, Achim A., Matsui, Takanori, Lee, F. T., Papenfuss, Anthony, Kuwano, Hiroyuki, Takahashi, Toshitada, Endo, Keigo, Old, Lloyd J.
• Format: Article
• Language: English
• Subjects: Aged; Antibodies, Monoclonal - blood; Antibodies, Monoclonal - pharmacokinetics; Antibodies, Monoclonal - therapeutic use; Antineoplastic agents; Biological and medical sciences; Dose-Response Relationship, Drug; Female; Humans; Immunotherapy; Iodine Radioisotopes; Male; Medical sciences; Membrane Glycoproteins - immunology; Metabolic Clearance Rate; Middle Aged; Original; Pharmacology. Drug treatments; Radioimmunodetection; Radioimmunotherapy; Stomach Neoplasms - diagnostic imaging; Stomach Neoplasms - drug therapy; Stomach Neoplasms - metabolism; Tissue Distribution; Treatment Outcome; Tumors
• ISSN: 1347-9032; 1349-7006
• DOI: 10.1111/j.1349-7006.2006.00324.x

In order to determine the in vivo characteristics of huA33, an open label dose escalation biopsy‐based phase I clinical trial and radioimmunolocalization study were conducted with a complement determinant region‐grafted humanized monoclonal antibody against the A33 antigen in patients with gastric carcinoma. Thirteen patients were entered onto one of four dose levels (1.0, 2.0, 5.0 or 10.0 mg/m2). Patients with locally advanced (UICC‐TNM [International Union Against Cancer–tumor, node, metastasis] stage over 2 but resectable at clinical diagnosis) gastric carcinoma received a single infusion of 131I‐huA33 1 week prior to surgery. Adverse events were monitored, and imaging studies with gamma camera plus ex vivo scintigraphy of the resected specimen, biodistribution study by dosimetry analysis of the biopsied and resected tissues, and immunohistochemical analysis were carried out and evaluated. No dose‐limiting toxicity was observed during the trial. Therefore, the maximum tolerated dose was not reached. Although cancer tissues with + intensity and 25%) extent by frozen and paraffin sections in the biopsied specimen showed positive ex vivo tumor images and positive antigen expression in resected gastric cancer specimens, and the biodistribution analysis showed tumor uptake of 131I‐huA33. In conclusion, humanized monoclonal antibody huA33 demonstrated selective localization to gastric cancer that expressed A33 antigen strongly. These excellent targeting characteristics of huA33 indicate potential for targeted therapy of advanced gastric cancer that is refractory to cytotoxic therapy, and could also be exploitable for curatively resected early gastric cancer in an adjuvant setting. (Cancer Sci 2006; 97: 1248–1254)