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| 2. |
- Mårtensson, Linda, et al.
(författare)
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Determining maximal tolerable dose of the monoclonal antibody BR96 labeled with 90Y or 177Lu in rats: establishment of a syngeneic tumor model to evaluate means to improve radioimmunotherapy.
- 2005
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 11:19 Pt 2, s. 7104-7108
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate therapeutic strategies, it is essential to use biological models reflecting important aspects of the clinical situation. The aim of the present study was to compare the maximal tolerable dose of the monoclonal antibody BR96 labeled with Y-90 or Lu-177 in immunocompetent rats. Maximal tolerable dose was defined as the highest activity that allows 100% of the animals to survive without clinical signs, such as infections, bleeding, or diarrhea, and with < 20% loss in body weight. Experimental Design: Increasing activity levels of BR96 labeled with Y-90 or Lu-177 were administered to groups of rats. Blood parameters, body weight, and general performance were monitored for 8 weeks. Results: Two days postinjection, all groups had decreased leukocyte counts down to 5% to 15% of initial values. Initiation of recovery (at 14-21 days) showed a dose-response relationship. All groups, except the group given the highest activity of Y-90 had complete resolution in their leukopenia. The decrease in platelets was delayed to days 7 to 14 postinjection with a dose dependent response regarding both severity of the nadir (10-40% of initial value) and the start of recovery. Animals in the groups given the highest activities of both Y-90 and Lu-177 exhibited skin infections on day 21. Conclusions: The results showed good reproducibility and dose-dependent toxicity for both radionuclides, indicating that the maximal tolerable dose for Lu-177 - BR96 (1,000 MBq/kg) is 1.7 times that for Y-90 - BR96 (600 MBq/kg) in rats. This model makes it feasible to evaluate strategies to escalate therapeutic doses to tumors without increasing normal tissue toxicity.
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| 3. |
- Mårtensson, Linda, et al.
(författare)
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Improved tumor targeting and decreased normal tissue accumulation through extracorporeal affinity adsorption in a two-step pretargeting strategy
- 2007
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 13:18, s. 5572-5576
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Evaluation of the possibilities of reducing the accumulation of radiolabeled streptavidin in radiosensitive organs by extracorporeal affinity adsorption (ECAT). Experimental Design: Rats were injected with biotinylated antibody and subjected to removal of the antibodies from the circulation by ECAT 24 h after injection (avidin column). Animals were then injected with In-111-1,4,7,10-tetra-azacylododecane N,N',N '',N'''-tetraacetic acid (DOTA) streptavidin. In a third step, animals were subjected to a second ECAT 8 h after injection to remove the DOTA-streptavidin from the circulation (biotin column). Biodistribution and tumor targeting of DOTA-streptavidin 24 h after injection was determined. Results: Elimination of biotinylated antibody by ECAT before injection of DOTA-streptavidin increased the tumor targeting by 50%. In addition, the levels of DOTA-streptavidin in liver and lymph nodes were reduced by 60%, which implied a 4.3- and 3.8-fold increase of tumor-to-liver and tumor-to-lymph node ratios, respectively. By doing a second ECAT to remove DOTA-streptavidin from the circulation, accumulation in normal tissues was reduced. However, this latter ECAT also reduced tumor accumulation by 25% (mostly corresponding to radioactivity in the circulation). Conclusions: ECAT was efficient as a means of removing biotinylated antibodies and would probably also be efficient for the clearance of streptavidin-conjugated antibodies. Conversely, the use of ECAT for removal of radiolabeled streptavidin seems not to offer any advantage.
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| 4. |
- Åkervall, Jan, et al.
(författare)
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Genetic and expression profiles of squamous cell carcinoma of the head and neck correlate with cisplatin sensitivity and resistance in cell lines and patients
- 2004
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 10:24, s. 8204-8213
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The choice of treatment for squamous cell carcinoma of the head and neck (SCCHN) is still primarily based on the tumor-node-metastasis classification. However, it is reasonable to believe that biological profiles of SCCHN may be independently associated with response to therapy. The aim of the present study was to examine genetic changes and gene expression profiles that might correlate with sensitivity to cisplatin [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay] in 10 SCCHN cell lines. Experimental Design: Five cisplatin-sensitive and five cisplatin-resistant cell lines [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay] were studied by comparative genomic hybridization, spectral karyotyping, and cDNA microarray analysis (21,632 sequence-validated human cDNA; confirmation by reverse transcriptase-PCR for selected genes). For the MET proto-oncogene, which showed low expression in the chemosensitive cell lines, we did immunohistochemical staining on SCCHN of 29 patients who received induction chemotherapy. Results: The five cisplatin-resistant cell lines showed significantly more genetic imbalances (regions of loss and amplification) and chromosomal abnormalities by comparative genomic hybridization and spectral karyotyping, respectively, than did the five cisplatin-sensitive cell lines. Microarray studies identified similar to60 genes that clearly distinguish between the two groups of cell lines. Some of these genes are known to be involved in tumor progression, metastasis, and drug resistance. We identified low expression of c-met (immunohistochemistry) as a predictive factor for complete response in nondiploid tumors (P = 0.026). Conclusions: We conclude that cisplatin sensitivity and resistance are related to distinctive differences in the genetic and expression profiles in individual SCCHN tumor cell lines and in SCCHN patients. The genes we have identified may serve as potential targets for novel treatment strategies.
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| 5. |
- Wang, Zhongmin, et al.
(författare)
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Blood pharmacokinetics of various monoclonal antibodies labeled with a new trifunctional chelating reagent for simultaneous conjugation with 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid and biotin before radiolabeling.
- 2005
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 11:19 Pt 2, s. 7171-7177
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Knowledge of the blood pharmacokinetics of monoclonal antibodies is crucial in deciding the optimal time for starting the administration of a "clearing agent"or using a "clearing device." The primary purpose was to investigate whether the pharmacokinetics of various antibodies labeled with the same chelator and In-111 differed significantly after i.v. injection in immunocompetent rats. A new trifunctional chelator called "1033" containing a biotin and a radiometal chelation moiety is introduced, making it possible to use only one conjugation procedure for the antibody. Experimental Design: Sixty-five non - tumor-bearing rats were included and divided into four groups (I-IV). The blood pharmacokinetics was investigated for rituximab, BR96, and trastuzumab labeled with 1033 and In-111 (I-III). The whole-body activity and activity uptake in muscle, liver, and kidney, which might explain differences in the early pharmacokinetics in blood, were also measured. hMN14 labeled with another chelator [1,4,7,10 -tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)], but with the same radionuclide ((111) In-biotin-DOTA-hMN14), was studied (IV).The blood pharmacokinetics from another 15 tumor-bearing rats was compared with those of non-tumor-bearing rats (III) by injection of In-111-1033-BR96. Results: No statistical difference was detected between the groups regarding the blood pharmacokinetics of rituximab, BR96, or trastuzumab. The pharmacokinetics and biodistribution of In-111-biotin-DOTA-hMN14 exhibited a clear difference compared with others. There were no significant differences in the blood pharmacokinetics of In-111-1033-BR96 between tumor-bearing rats and non-tumor-bearing rats. Conclusions: Different antibodies labeled with the trifunctional chelator 1033 and In-111 did not exhibit different blood pharmacokinetics, which means that the pharmacokinetics could be predicted irrespective of the IgG1 antibody chosen. A small tumor burden did not change the pharmacokinetics of the radioimmunoconjugates.
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| 7. |
- Lindén, Ola, et al.
(författare)
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Radioimmunotherapy using 131I-labeled anti-CD22 monoclonal antibody (LL2) in patients with previously treated B-cell lymphomas
- 1999
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 5:10 Suppl, s. 3287-3291
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Tidskriftsartikel (refereegranskat)abstract
- Experience in using rapidly internalizing antibodies, such as the anti-CD22 antibody, for radioimmunotherapy of B-cell lymphomas is still limited. The present study was conducted to assess the efficacy and toxicity of a 131I-labeled anti-CD22 monoclonal antibody (mAb), LL2, in patients with B-cell lymphomas failing first- or second-line chemotherapy. Eligible patients were required to have measurable disease, less than 25% B cells in unseparated bone marrow, and an uptake of 99mTc-labeled LL2Fab' in at least one lymphoma lesion on immunoscintigram. Eight of nine patients examined with immunoscintigraphy were unequivocally found to have an uptake, and therapy with 131I-labeled anti-CD22 [1330 MBq/m2 (36 mCi/m2)] preceded by 20 mg of naked anti-CD22 mAb was administered. Three patients achieved partial remission (duration, 12, 3, and 2 months), and one patient with progressive lymphoma showed stable disease for 17 months. Four patients exhibited progressive disease. The toxicity was hematological. Patients with subnormal counts of neutrophils or platelets before therapy seemed to be more at risk for hematological side effects. Radioimmunotherapy in patients with B-cell lymphomas using 131I-labeled mouse anti-CD22 can induce objective remission in patients with aggressive as well as indolent lymphomas who have failed prior chemotherapy.
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