COMPARISON OF THE BIODISTRIBUTION AND THE EFFICACY OF MONOCLONAL-ANTIBODY 323 A3 LABELED WITH EITHER I-131 OR RE-186 IN HUMAN OVARIAN-CANCER XENOGRAFTS/
E. Kievit et al., COMPARISON OF THE BIODISTRIBUTION AND THE EFFICACY OF MONOCLONAL-ANTIBODY 323 A3 LABELED WITH EITHER I-131 OR RE-186 IN HUMAN OVARIAN-CANCER XENOGRAFTS/, International journal of radiation oncology, biology, physics, 38(4), 1997, pp. 813-823
Citations number
31
Categorie Soggetti
Oncology,"Radiology,Nuclear Medicine & Medical Imaging
Purpose: The radionuclide Re-186 has favorable physical characteristic
s for use in radioimmunotherapy, including the emission of beta-partic
les of a high energy and a low-abundance of gamma-emission, The gamma-
emission, in particular, is ideal for tumor imaging and poses less haz
ards to the patient and the medical personnel when compared with the g
amma-emission of the widely used radionuclide I-131, In the present st
udy, we determined whether Re-186-labeled monoclonal antibody 323/A3 m
ay be better suited for the treatment of ovarian cancer than I-131-323
/A3. Methods and Materials: We compared the biodistribution and the ef
ficacy of Re-186- and I-131-labeled 323/A3 in nude mice bearing s.c. t
he human ovarian cancer xenografts FMa, OVCAR-3 and Ov.Pe. Re-186 was
conjugated to 323/A3 with the use of the S-benzoylmercaptoacetyltrigly
cine (S-benzoyl-MAG3) chelate. Results: A molar ratio of Re-MAG3:323/A
3 of 3:1 did not affect the integrity and the pharmacokinetic behaviou
r of the MAb, The tumor uptake and the retention of Re-186- and I-131-
labeled 323/A3 were comparable, but the cumulative absorbed radiation
dose in the tumor delivered by Re-186-323/A3 was 1.3-fold higher than
that of I-131-323/A3, When mice were treated with equivalent radionucl
ide doses, the tumor growth inhibition induced by Re-186-323/A3 was si
milar or slightly better when compared with the efficacy of I-131-323/
A3, When mice were treated with radionuclide doses that were adjusted
to obtain equal cumulative absorbed radiation doses in the tumor for b
oth conjugates, I-131-323/A3 was slightly more effective in the inhibi
tion of the growth of FMa and OVCAR-3 xenografts. Conclusions: The fav
orable physical characteristics of Re-186 as well as its efficacy when
conjugated to a MAb indicate Re-186 as an attractive radionuclide in
radioimmunotherapy of ovarian cancer patients, (C) 1997 Elsevier Scien
ce Inc.