Distribution of labelled anti-tenascin antibodies and fragments after injection into intact or partly resected C6-gliomas in rats (original) (raw)
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Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2005
The objective was to perform dosimetry and evaluate dose-response relationships in newly diagnosed patients with malignant brain tumors treated with direct injections of (131)I-labeled anti-tenascin murine 81C6 monoclonal antibody (mAb) into surgically created resection cavities (SCRCs) followed by conventional external-beam radiotherapy and chemotherapy. Absorbed doses to the 2-cm-thick shell, measured from the margins of the resection cavity interface, were estimated for 33 patients with primary brain tumors. MRI/SPECT registrations were used to assess the distribution of the radiolabeled mAb in brain parenchyma. Results from biopsies obtained from 15 patients were classified as tumor, radionecrosis, or tumor and radionecrosis, and these were correlated with absorbed dose and dose rate. Also, MRI/PET registrations were used to assess radiographic progression among patients. This therapeutic strategy yielded a median survival of 86 and 79 wk for all patients and glioblastoma multif...
Cancer research, 1988
Lack of tumor specificity renders current modalities for treating malignant glioma ineffective. The administration of 131I-labeled monoclonal antibody (Mab) 81C6, which reacts with the glioma-associated extracellular matrix antigen, tenascin, to nude mice carrying s.c. human glioma xenografts has resulted in significant tumor growth delay and tumor regression. In this study, we evaluated the therapeutic efficacy of 131I-labeled 81C6 in athymic rats bearing intracranial human glioma xenografts, a more appropriate model for human gliomas. Mab 81C6, an IgG2b immunoglobulin, and an isotype-matched control Mab, 45.6, were labeled at 12.5-23.6 mCi/mg with chloramine-T. The Mabs were given i.v. at 1.25 and 2.5 mCi/animal for 131I-labeled 81C6, and 1.25 mCi for 131I-labeled 45.6 control. Therapeutic response was evaluated by survival prolongation using Wilcoxon rank sum analysis. Three experiments were done. No significant survival prolongation was found in the trial in which the average tu...
Cell Biophysics, 1994
Thirty patients with recurrent glioblastomas (29 brain, 1 spinal cord) received intralesional radioimmunotherapy aiming to control the progression of the tumor after surgery and radiotherapy. The BC-2 and/or BC-4 murine MAbs (Sorin-Biomedica, Saluggia, Italy) were utilized. They strongly react against tenascin (TN), which is an extracellular antigen expressed in large amounts by the stroma of glioblastoma but not by normal brain. The MAbs were labeled with 1-131 and were injected directly into the tumor mass to maximize the antibody concentration in the tumor and to irradiate the neoplastic cells. The dose consisted, on average, of 3 mg antibody and 1100 MBq 1-131. In most cases the radioimmunotherapy (RIT) applications were repeated two, three, or four times. No systemic adverse reactions were recorded. The brain tolerance to direct antibodies injection was quite good. The antibody concentration in the tumor was high and the MAb residence time in neoplastic tumor was prolonged. Consequently the mean radiation dose to the tumor was high: > 25,000
Cancer research, 1995
Two murine monoclonal antibodies, BC-2 and BC-4, raised against tenascin and labeled with 131I were infused locally in the site of neoplastic disease by means of a removable (16 patients) or indwelling (34 patients) catheter. Fifty patients bearing a malignant glioma were treated. Twenty-six of these were suffering from recurrent disease; their tumors relapsed within 9 months (median) after treatment. The remaining 24 cases had a newly diagnosed tumor, and local radioimmunotherapy (RIT) was given immediately after surgery and radiochemotherapy. All efforts were made to reduce the tumor before the infusion of the radiopharmaceutical. Therefore, 22 cases with relapsing glioma underwent additional debulking surgery, which led to total or subtotal removal of tumor in 9 of the patients. Altogether, 28 patients had intralesional RIT when the disease was minimal or microscopic. Conversely, 22 cases underwent local RIT with a tumor the diameter of which was > 2 cm. In many cases, the inf...
Journal of Neuroimmunology, 1987
Radioiodinated murine monoclonal antibodies (Mabs) 81C6, Me 1-14, C12, D12, and E9, made against or reactive with human gliomas but not normal brain, and Mab UJ13A, a pan-neuroectodermal Mab reactive with normal human glial and neural cells, were evaluated in paired label studies in the D-54 MG subcutaneous human glioma xenograft model system in nude mice. Following intravenous injection in the tail vein of mice bearing 200-400 mm 3 tumors, specific localization of Mabs to tumor over time (6 h-9 days) was evaluated by tissue counting; each Mab demonstrated a unique localization profile. The comparison of localization indices (LI), determined as a ratio of tissue level of Mab to control immunoglobulin with simultaneous correction for blood levels of each, showed Mabs 81C6 and Me 1-14 to steadily accumulate in glioma xenografts, maintaining LI from 5-20 at 7-9 days after Mab injection. Mab UJ13A peaked at day 1, maintaining this level through day 2, and declining thereafter. Mabs D12 and C12 peaked at days 3 and 4, respectively, and E9 maintained an LI of > 3 from days 3-9. Percent injected dose localized/g of tumor varied from a peak high of 16% (81C6) to a low of 5% (Me 1-14 and UJ13A). Immunoperoxidase histochemistry, performed with each Mab on a battery of primary human brain neoplasms, revealed that Mabs 81C6 and E9, which demonstrated the highest levels of percent injected dose localized/g of tumor over time, reacted with antigens expressed in the extracellular matrix. This finding suggests that extracellular matrix localization of antigen represents a biologically significant factor affecting localization and/or binding in the xenograft model used. The demonstration of significant localization, varied kinetics and patterns of localization of this localizing Mab panel warrants their continued investigation as potential imaging and therapeutic agents for human trials.
International Journal of Radiation Oncology Biology Physics, 2000
Purpose: The objective of this study was to perform the dosimetry and evaluate the dose-response relationships in newly diagnosed patients with malignant brain tumors treated by direct injections of 131 I-labeled 81C6 monoclonal antibody (MAb) into surgically created resection cavities (SCRCs). Methods and Materials: Absorbed doses to the 2-cm-thick shell as measured from the margins of the resection cavity interface were estimated for 42 patients with primary brain tumors. MR images were used to assess the enhanced-rim volume as a function of time after radiolabeled MAb therapy. Biopsy samples were obtained from 15 patients and 1 autopsy. Results: The average absorbed dose [range] to the 2-cm shell region was 32 [3-59] Gy. For the endpoint of minimal time to MR contrast enhancement, the optimal absorbed dose and initial dose-rate were 43 ؎ 16 Gy and 0.41 ؎ 0.10 Gy/h, respectively. There was a correlation between the absorbed dose and dose rate to the shell region and biopsy outcome (tumor recurrence, radionecrosis, and tumor recurrence and/or radionecrosis). In this Phase I study, the maximum tolerated dose (MTD) was 120 mCi. At this MTD, the estimated average absorbed dose and initial dose rate to the 2-cm shell were 41 [9 -89] Gy and 0.51 [0.24 -1.13] Gy/h, respectively. These values are in agreement with the optimal values based on the time to MR lesion rim enhancement. Conclusions: The average absorbed dose to the 2-cm shell region varied considerably and mainly depended on cavity volume. In future clinical trials, the administered activity of 131 I-labeled 81C6 MAb may be adjusted based on cavity volume in order to deliver the optimal absorbed dose of 43 Gy rather than giving a fixed administered activity. © 2000 Elsevier Science Inc.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2006
Results from animal experiments have shown that human IgG2/mouse chimeric antitenascin 81C6 (ch81C6) monoclonal antibody exhibited higher tumor accumulation and enhanced stability compared with its murine parent. Our objective was to determine the effect of these differences on the maximum tolerated dose (MTD), pharmacokinetics, dosimetry, and antitumor activity of (131)I-ch81C6 administered into the surgically created resection cavity (SCRC) of malignant glioma patients. In this phase I trial, eligible patients received a single injection of (131)I-ch81C6 administered through a Rickham catheter into the SCRC. Patients were stratified as newly diagnosed and untreated (stratum A), newly diagnosed after external beam radiotherapy (XRT) (stratum B), and recurrent (stratum C). (131)I-ch81C6 was administered either before (stratum A) or after (stratum B) conventional XRT for newly diagnosed patients. In addition, chemotherapy was prescribed for all patients after (131)I-ch81C6 administra...
Clinical cancer research : an official journal of the American Association for Cancer Research, 1999
A Phase I radioimmunotherapy trial was conducted in which radioconjugated monoclonal antibody (MAb) was directly infused into the tumor or postoperative tumoral bed in patients with high-grade malignant glioma. BC-4, a murine MAb that recognizes tenascin, was used in these studies. The MAb was labeled with 90Y, a pure beta emitter with maximum energy of 2.284 MeV, which can penetrate into tissue up to 0.5-0.7 cm. Stable 90Y-labeled MAb conjugates were prepared using the chelator p-isothiocyanatobenzyl derivative of diethylenetriaminepentaacetic acid (ITC-Bz-DTPA), obtaining >95% labeling efficiency and conserving the antibodies' immunoreactivity (>85%). Twenty patients, 2 with anaplastic astrocytoma and 18 with glioblastoma, were included in the study. All of the patients had been treated previously with conventional therapies (surgery, external radiotherapy, and chemotherapy) and presented with progressive disease not amenable to further treatment. A dose-escalation study...
Biochemistry (moscow) Supplement Series B: Biomedical Chemistry, 2008
Employment of radiolabeled antibodies in biological studies, allows their specific accumulation in organs and tissues to be accurately detected. However, stability of such radiolabeled antibodies depends on both the method of labeling and particular experimental conditions. Therefore, stability of labeled antibodies should be determined in every particular experiment. In this study we have investigated stability of the 125I-labeled monoclonal antibodies