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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. |
- Thorek, Daniel L.J., et al.
(författare)
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Harnessing androgen receptor pathway activation for targeted alpha particle radioimmunotherapy of breast cancer
- 2019
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 25:2, s. 881-891
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The impact of androgen receptor (AR) activity Results: D-Norgestrel and DHT activated the AR pathway, in breast cancer biology is unclear. We characterized and while 17b-Estradiol did not. Competitive binding for AR tested a novel therapy to an AR-governed target in breast protein showed similar affinity between DHT and D-Norges-cancer. trel, indicating direct AR–ligand interaction. In vivo production Experimental Design: We evaluated the expression of of hK2 was sufficient to achieve site-specific delivery of ther-prototypical AR gene products human kallikrein 2 (hK2) apeutic radionuclide to tumor tissue at >20-fold over back- and PSA in breast cancer models. We screened 13 well-ground muscle uptake; effecting long-term local tumor characterized breast cancer cell lines for hK2 and PSA control. production upon in vitro hormone stimulation by testoster-Conclusions: [225Ac]hu11B6 targeted radiotherapy one [dihydrotestosterone (DHT)]. AR-positive lines were was potentiated by DHT and by D-Norgestrel in murine further evaluated by exposure to estrogen (17b-Estradiol) xenograft models of breast cancer. AR activity in and the synthetic progestin D-Norgestrel. We then evaluated breast cancer correlates with kallikrein-related peptidase-2 an anti-hK2–targeted radiotherapy platform (hu11B6), and can be activated by D-Norgestrel, a common con-labeled with alpha (a)-particle emitting Actinium-225, to traceptive, and AR induction can be harnessed for hK2-specifically treat AR-expressing breast cancer xenografts targeted breast cancer a-emitter radiotherapy. under hormone stimulation.
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| 5. |
- Veach, Darren R., et al.
(författare)
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PSA-Targeted Alpha-, Beta-, and Positron-emitting immunotheranostics in murine prostate cancer models and nonhuman primates
- 2021
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 27:7, s. 2050-2060
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Most patients with prostate cancer treated with androgen receptor (AR) signaling inhibitors develop therapeutic resistance due to restoration of AR functionality. Thus, there is a critical need for novel treatment approaches. Here we investigate the theranostic potential of hu5A10, a humanized mAb specifically targeting free PSA (KLK3). Experimental Design: LNCaP-AR (LNCaP with overexpression of wildtype AR) xenografts (NSG mice) and KLK3-Hi- Myc transgenic mice were imaged with 89Zr- or treated with 90Y- or 225Ac-labeled hu5A10; biodistribution and subcellular localization were analyzed by gamma counting, PET, autoradiography, and microscopy. Therapeutic efficacy of [225Ac]hu5A10 and [90Y]hu5A10 in LNCaP-AR tumors was assessed by tumor volume measurements, time to nadir (TTN), time to progression (TTP), and survival. Pharmacokinetics of [89Zr]hu5A10 in nonhuman primates (NHP) were determined using PET. Results: Biodistribution of radiolabeled hu5A10 constructs was comparable in different mouse models. Specific tumor uptake increased over time and correlated with PSA expression. Treatment with [90Y]/[225Ac]hu5A10 effectively reduced tumor burden and prolonged survival (P ≤ 0.0054). Effects of [90Y]hu5A10 were more immediate than [225Ac]hu5A10 (TTN, P < 0.0001) but less sustained (TTP, P < 0.0001). Complete responses were observed in 7 of 18 [225Ac]hu5A10 and 1 of 9 mice [90Y]hu5A10. Pharmacokinetics of [89Zr]hu5A10 were consistent between NHPs and comparable with those in mice. [89Zr]hu5A10-PET visualized the NHP-prostate over the 2-week observation period. Conclusions: We present a complete preclinical evaluation of radiolabeled hu5A10 in mouse prostate cancer models and NHPs, and establish hu5A10 as a new theranostic agent that allows highly specific and effective downstream targeting of AR in PSAexpressing tissue. Our data support the clinical translation of radiolabeled hu5A10 for treating prostate cancer.
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| 6. |
- 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. |
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| 8. |
- 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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