RT Journal Article
SR Electronic
T1 Imaging of Non-Small Cell Lung Cancers with a Monoclonal Antibody, KC-4G3, Which Recognizes a Human Milk Fat Globule Antigen
JF Cancer Research
JO Cancer Res
FD American Association for Cancer Research
SP 7068
OP 7076
VO 50
IS 21
A1 Dienhart, David G.
A1 Schmelter, Raymond F.
A1 Lear, James L.
A1 Miller, Gary J.
A1 Glenn, Stephan D.
A1 Bloedow, Duane C.
A1 Kasliwal, Ravindra
A1 Moran, Patrick
A1 Seligman, Paul
A1 Murphy, James R.
A1 Kortright, Kenneth
A1 Bunn, Paul A.
YR 1990
UL http://cancerres.aacrjournals.org/content/50/21/7068.abstract
AB To determine the role of lung cancer tumor imaging with monoclonal antibodies directed against high molecular weight human milk fat globule antigens, we administered i.v. 111In-KC-4G3 to 24 patients with advanced non-small cell lung cancer. One mg of 111In-KC-4G3 was mixed with 0, 9, 49, 99, or 499 mg of unlabeled KC-4G3 and infused i.v. over 1 to 5 h. The mean 111In-KC-4G3 radiochemical purity was >97% and the resultant immunoreactivity averaged 62%. Successful imaging of cancer sites was accomplished in 92% of 24 patients, and 57% of 91 total lesions were visualized. Successful localization of tumor sites related to size (P < 0.001), with 81% of lesions >3.0 cm in diameter, 50% of lesions 1.5 to 3 cm, and 6% of lesions <1.5 cm successfully imaging, and to location (P < 0.05), with 69% of pulmonary lesions, 80% of soft tissue lesions, and only 32% of bone metastases being visualized. Nonspecific reticuloendothelial uptake of radioactivity was a major problem. Approximately 35% of 111In was chelated to serum transferrin by 24 and 48 h after infusion. The mean t1/2, for plasma radioisotope and immunoreactive KC-4G3 was 29 and 27 h, respectively. There was no correlation between total infused antibody dose and imaging success or between total dose and effect on 111In and KC-4G3 kinetics. Circulating free KC-4 antigen was measurable in all but one patient before study. Tumor biopsy following infusion could demonstrate antibody presence but not saturable antigen binding. We conclude that (a) 111In-KC-4G3 demonstrates successful tumor localization in non-small cell lung cancers bearing generally high expression of its antigen and (b) further investigations to diminish nonspecific radioactivity for imaging and utilization of high dose radiolabeled antibody for therapeutic intent are warranted. ©1990 American Association for Cancer Research.