| 1. |
- Andersson, Håkan, 1944, et al.
(författare)
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Astatine-211-labeled antibodies for treatment of disseminated ovarian cancer: an overview of results in an ovarian tumor model
- 2003
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Ingår i: Clin Cancer Res. - 1078-0432. ; 9:10 Pt 2
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of the study was to establish and refine a preclinical model to alpha-immunoradiotherapy of ovarian cancer. EXPERIMENTAL DESIGN: At-211 was produced by cyclotron irradiation of a bismuth-209 target and isolated using a novel dry distillation procedure. Monoclonal antibodies were radiohalogenated with the intermediate reagent N-succinimidyl 3-(trimethylstannyl)benzoate and characterized in terms of radiochemical yield and in vitro binding properties. In vitro OVCAR-3 cells were irradiated using an external Cobalt-60 beam, as reference, or At-211-albumin and labeled antibody. Growth assays were used to establish cell survival. A Monte Carlo program was developed to simulate the energy imparted and the track length distribution. Nude mice were used for studies of WBC depression, with various activities of Tc-99m antibodies, as reference, and At-211 antibodies. In efficacy studies, OVCAR-3 cells were inoculated i.p., and animals were treated 2 weeks later. The animals were either dissected 6 weeks later or followed-up for long-term survival. RESULTS: A rapid distillation procedure, as well as a rapid and high-yield, single-pot labeling procedure, was achieved. From growth inhibition data, the relative biological effectiveness of the alpha-emission for OVCAR-3 cells was estimated to be approximately 5, which is in the same range as found in vivo for hematological toxicity. At-211 MOv18 was found to effectively inhibit the development of tumors and ascites, also resulting in long-term survival without significant toxic effect. CONCLUSIONS: Use of the short-range, high-linear energy transfer alpha-emitter At-211 conjugated to a surface epitope-recognizing monoclonal antibody appears to be highly efficient without significant toxicity in a mouse peritoneal tumor model, urging a Phase I clinical trial.
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| 2. |
- Andersson, Håkan, 1944, et al.
(författare)
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Comparison of the therapeutic efficacy of 211At- and 131I-labelled monoclonal antibody MOv18 in nude mice with intraperitoneal growth of human ovarian cancer.
- 2001
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Ingår i: Anticancer research. - 0250-7005. ; 21:1A, s. 409-12
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study was to compare the therapeutic efficacy of the alpha-emitter Astatine-211 with the beta-emitter Iodine-131 bound to the specific monoclonal antibody MOv18. The measurements were performed in an ovarian cancer cell line (NIH:OVCAR 3) growing intraperitoneally in nude mice. Two weeks after the intraperitoneal inoculation of 1 x 10(7) cells of the human ovarian cancer cell line NIH:OVCAR-3 twenty mice were treated intraperitoneally with the specific monoclonal antibody MOv-18 labelled with either 211At (310-400 kBq) or 131I (5100-6200 kBq). The pharmacokinetics and biodistribution of labelled antibody in tumour-free animals were studied and the resulting bone marrow dose was estimated. When the mice were treated with 211At-labelled antibody 9 out of 10 mice were free of macro- and microscopic tumour compared to 3 out of 10 when Iodine-131 was used. The equivalent dose to the bone marrow was 2.4-3.1 Sv from 211At- and 3.4-4.1 Sv from 131I-irradiation. The therapeutic efficacy of 211At-labelled specific antibody is very good and, at approximately equivalent bone marrow doses, better than that of 131I.
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| 3. |
- Andersson, Håkan, 1944, et al.
(författare)
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Intraperitoneal alpha-particle radioimmunotherapy of ovarian cancer patients: pharmacokinetics and dosimetry of (211)At-MX35 F(ab')2--a phase I study.
- 2009
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Ingår i: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505. ; 50:7, s. 1153-60
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Tidskriftsartikel (refereegranskat)abstract
- The alpha-emitter (211)At labeled to a monoclonal antibody has proven safe and effective in treating microscopic ovarian cancer in the abdominal cavity of mice. Women in complete clinical remission after second-line chemotherapy for recurrent ovarian carcinoma were enrolled in a phase I study. The aim was to determine the pharmacokinetics for assessing absorbed dose to normal tissues and investigating toxicity. METHODS: Nine patients underwent laparoscopy 2-5 d before the therapy; a peritoneal catheter was inserted, and the abdominal cavity was inspected to exclude the presence of macroscopic tumor growth or major adhesions. (211)At was labeled to MX35 F(ab')(2) using the reagent N-succinimidyl-3-(trimethylstannyl)-benzoate. Patients were infused with (211)At-MX35 F(ab')(2) (22.4-101 MBq/L) in dialysis solution via the peritoneal catheter. gamma-Camera scans were acquired on 3-5 occasions after infusion, and a SPECT scan was acquired at 6 h. Samples of blood, urine, and peritoneal fluid were collected at 1-48 h. Hematology and renal and thyroid function were followed for a median of 23 mo. RESULTS: Pharmacokinetics and dosimetric results were related to the initial activity concentration (IC) of the infused solution. The decay-corrected activity concentration decreased with time in the peritoneal fluid to 50% IC at 24 h, increased in serum to 6% IC at 45 h, and increased in the thyroid to 127% +/- 63% IC at 20 h without blocking and less than 20% IC with blocking. No other organ uptakes could be detected. The cumulative urinary excretion was 40 kBq/(MBq/L) at 24 h. The estimated absorbed dose to the peritoneum was 15.6 +/- 1.0 mGy/(MBq/L), to red bone marrow it was 0.14 +/- 0.04 mGy/(MBq/L), to the urinary bladder wall it was 0.77 +/- 0.19 mGy/(MBq/L), to the unblocked thyroid it was 24.7 +/- 11.1 mGy/(MBq/L), and to the blocked thyroid it was 1.4 +/- 1.6 mGy/(MBq/L) (mean +/- SD). No adverse effects were observed either subjectively or in laboratory parameters. CONCLUSION: This study indicates that by intraperitoneal administration of (211)At-MX35 F(ab')(2) it is possible to achieve therapeutic absorbed doses in microscopic tumor clusters without significant toxicity.
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| 4. |
- Andersson, Håkan, 1944
(författare)
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Radioimmunotherapy of experimental ovarian cancer with Astatine-211. An in vivo model for consolidation treatment in women
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- About 850 new cases of ovarian cancer are diagnosed in Sweden every year. In 75 % of the patients the tumour has spread outside the ovaries. The standard treatment is surgery followed by six courses of combination chemotherapy. In spite of a very high frequency of clinical complete responses the 5-year survival is not satisfactory. Thus there is a great need for consolidating therapy.Radioimmunotherapy (RIT), i.e. treatment with specific monoclonal antibodies (MAb) labelled with radionuclides has been tried for various tumours experimentally and clinically. In most studies b-emitters have been used but for micrometastases an a-emitter with a very short tissue range may be better.The purpose of this study was to examine the in vitro effect of the a-emitter Astatine-211 (211At) and to investigate the therapeutic efficacy of regional administration of the specific antibody MOv18 labelled with 211At to nude mice with intraperitoneal growth of human ovarian cancer. Methods. For the in vitro studies the two human cancer cell lines NIH:OVCAR-3 and Colo-205 were used. Cell suspensions were treated with free 211At, 211At-albumin, 211At-Mab or with photon irradiation. The human ovarian cancer cell line NIH:OVCAR-3 was used for the in vivo studies. Two weeks after the inoculation of cells, when the tumour still was microscopic, 211At-MOv18 was injected intraperitoneally. The therapeutic effect was evaluated six weeks later except in the long-term studyResults. In vitro the uptake of free 211At on both cell lines was unexpectedly high. A low number (19-31) of 211At decays on the cell surface was needed for 37% cell survival for both cell types.In the short term in vivo studies 18 of 20 mice were tumour-free when 211At-MOv18 was injected i.p. In the long-term study the survival was significantly better for treated than for untreated mice. Thirty-three per cent of the animals were tumour-free at the end of the study.Conclusion. Intraperitoneal radioimmunotherapy with an 211At-labelled specific antibody is an effective treatment of human ovarian cancer growing in nude mice. Hopefully, this treatment will be of value as consolidating treatment in women with minimal residual disease after surgery and chemotherapy
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| 5. |
- Bäck, Tom, 1964, et al.
(författare)
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211At radioimmunotherapy of subcutaneous human ovarian cancer xenografts: evaluation of relative biologic effectiveness of an alpha-emitter in vivo
- 2005
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Ingår i: J Nucl Med. - 0161-5505. ; 46:12, s. 2061-7
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Tidskriftsartikel (refereegranskat)abstract
- The use of alpha-particle emitters in radioimmunotherapy (RIT) appears to be promising. We previously obtained convincing results in the treatment of microscopic intraperitoneal ovarian cancer in nude mice by using the alpha-emitter 211At. This study was performed to evaluate the relative biological effectiveness (RBE) of 211At compared with that of 60Co gamma-irradiation in an RIT model. Our endpoint was growth inhibition (GI) of subcutaneous xenografts. METHODS: GI after irradiation was studied with subcutaneous xenografts of the human ovarian cancer cell line NIH:OVCAR-3 implanted in nude mice. The animals received an intravenous injection of 211At-labeled monoclonal antibody MX35 F(ab')2 at different levels of radioactivity (0.33, 0.65, and 0.90 MBq). Control mice received unlabeled MX35 F(ab')2 only. To calculate the mean absorbed dose to tumor, a separate biodistribution study established the uptake of 211At in tumors and organs at different times after injection. External irradiation of the tumors was performed with 60Co. Tumor growth was monitored, and the normalized tumor volume (NTV) was calculated for each tumor. GI was defined by dividing the NTV values by the fitted NTV curve obtained from the corresponding control mice. To compare the biologic effects of the 2 radiation qualities, the mean value for GI (from day 8 to day 23) was plotted for each tumor as a function of its corresponding absorbed dose. From exponential fits of these curves, the doses required for a GI of 0.37 (D37) were derived, and the RBE of 211At was calculated. RESULTS: The biodistribution study showed the uptake of the immunoconjugate by the tumor (amount of injected radioactivity per gram) to be 14% after 7 h. At 40 h, the ratio of uptake in tumors to uptake in blood reached a maximum value of 6.2. The administered activities of 211At corresponded to doses absorbed by tumors of 1.35, 2.65, and 3.70 Gy. The value (mean+/-SEM) for D37 was 1.59+/-0.08 Gy. Tumor growth after 60Co external irradiation showed a value for D37 of 7.65+/-1.0 Gy. The corresponding RBE of 211At irradiation was 4.8+/-0.7. CONCLUSION: Using a tumor GI model in nude mice, we were able to derive an RBE of alpha-particle RIT with 211At. The RBE was found to be 4.8+/-0.7.
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| 6. |
- Cederkrantz, Elin, et al.
(författare)
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Absorbed Doses and Risk Estimates of (211)At-MX35 F(ab')2 in Intraperitoneal Therapy of Ovarian Cancer Patients.
- 2015
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Ingår i: International journal of radiation oncology, biology, physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 93:3, s. 569-76
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Tidskriftsartikel (refereegranskat)abstract
- Ovarian cancer is often diagnosed at an advanced stage with dissemination in the peritoneal cavity. Most patients achieve clinical remission after surgery and chemotherapy, but approximately 70% eventually experience recurrence, usually in the peritoneal cavity. To prevent recurrence, intraperitoneal (i.p.) targeted α therapy has been proposed as an adjuvant treatment for minimal residual disease after successful primary treatment. In the present study, we calculated absorbed and relative biological effect (RBE)-weighted (equivalent) doses in relevant normal tissues and estimated the effective dose associated with i.p. administration of (211)At-MX35F(ab')2.
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| 7. |
- Elgqvist, Jörgen, 1963, et al.
(författare)
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Administered activity and metastatic cure probability during radioimmunotherapy of ovarian cancer in nude mice with 211At-MX35 F(ab')2.
- 2006
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Ingår i: International journal of radiation oncology, biology, physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 66:4, s. 1228-37
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To elucidate the therapeutic efficacy of alpha-radioimmunotherapy of ovarian cancer in mice. This study: (i) estimated the minimum required activity (MRA), giving a reasonable high therapeutic efficacy; and (ii) calculated the specific energy to tumor cell nuclei and the metastatic cure probability (MCP) using various assumptions regarding monoclonal-antibody (mAb) distribution in measured tumors. The study was performed using the alpha-particle emitter Astatine-211 (211At) labeled to the mAb MX35 F(ab')2. METHODS AND MATERIALS: Animals were inoculated intraperitoneally with approximately 1 x 10(7) cells of the cell line NIH:OVCAR-3. Four weeks later animals were treated with 25, 50, 100, or 200 kBq 211At-MX35 F(ab')2 (n = 74). Another group of animals was treated with a nonspecific mAb: 100 kBq 211At-Rituximab F(ab')2 (n = 18). Eight weeks after treatment the animals were sacrificed and presence of macro- and microscopic tumors and ascites was determined. An MCP model was developed and compared with the experimentally determined tumor-free fraction (TFF). RESULTS: When treatment was given 4 weeks after cell inoculation, the TFFs were 25%, 22%, 50%, and 61% after treatment with 25, 50, 100, or 200 kBq (211)At-MX35 F(ab')2, respectively, the specific energy to irradiated cell nuclei varying between approximately 2 and approximately 400 Gy. CONCLUSION: As a significant increase in the therapeutic efficacy was observed between the activity levels of 50 and 100 kBq (TFF increase from 22% to 50%), the conclusion was that the MRA is approximately 100 kBq (211)At-MX35 F(ab')2. MCP was most consistent with the TFF when assuming a diffusion depth of 30 mum of the mAbs in the tumors.
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| 8. |
- Elgqvist, Jörgen, 1963, et al.
(författare)
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Alpha-radioimmunotherapy of intraperitoneally growing OVCAR-3 tumors of variable dimensions: Outcome related to measured tumor size and mean absorbed dose.
- 2006
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Ingår i: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 47:8, s. 1342-50
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this work was to (a) investigate the efficacy of radioimmunotherapy using 211At-MX35 F(ab')2 or 211At-Rituximab F(ab')2 (nonspecific antibody) against differently advanced ovarian cancer in mice; (b) image the tumor growth on the peritoneum; and (c) calculate the specific energy and mean absorbed dose to tumors and critical organs. METHODS: Two experiments with 5-wk-old nude mice (n = 100 + 93), intraperitoneally inoculated with approximately 1 x 10(7) NIH:OVCAR-3 cells, were done. At either 1, 3, 4, 5, or 7 wk after inoculation animals were intraperitoneally treated with approximately 400 kBq 211At-MX35 F(ab')2 (n = 50 + 45), approximately 400 kBq 211At-Rituximab F(ab')2 (n = 25 + 24), or unlabeled Rituximab F(ab')2 (n = 25 + 24). At the time of treatment 29 animals were sacrificed and biopsies were taken for determination of tumor sizes using scanning electron microscopy (SEM). Eight weeks after each treatment the animals were sacrificed and the presence of macro- and microscopic tumors and ascites was determined. The specific energy and mean absorbed dose to tumors were calculated. The activity concentration was measured in critical organs and abdominal fluid. RESULTS: When given treatment 1, 3, 4, 5, or 7 wk after cell inoculation the tumor-free fraction (TFF) was 95%, 68%, 58%, 47%, 26%, and 100%, 80%, 20%, 20%, and 0% when treated with 211At-MX35 F(ab')2 or 211At-Rituximab F(ab')2, respectively. The SEM images revealed maximum tumor radius of approximately 30 mum 1 wk after cell inoculation, increasing to approximately 340 mum at 7 wk. Specific energy to cell nuclei varied between 0 and approximately 540 Gy, depending on assumptions regarding activity distribution and tumor size. The mean absorbed dose to thyroid, kidneys, and bone marrow was approximately 35, approximately 4, and approximately 0.3 Gy, respectively. CONCLUSION: Treatment with 211At-MX35 F(ab')2 or 211At-Rituximab F(ab')2 resulted in a TFF of 95%-100% when the tumor radius was < or =30 microm. The TFF was decreased (TFF < or = 20%) for 211At-Rituximab F(ab')2 when the tumor radius exceeded the range of the alpha-particles. The specific antibody gave for these tumor sizes a significantly better TFF, explained by a high mean absorbed dose (>22 Gy) from the activity bound to the tumor surface and probably some contribution from penetrating activity.
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| 9. |
- Elgqvist, Jörgen, 1963, et al.
(författare)
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Fractionated radioimmunotherapy of intraperitoneally growing ovarian cancer in nude mice with 211At-MX35 F(ab')2: therapeutic efficacy and myelotoxicity
- 2006
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Ingår i: Nucl Med Biol. - : Elsevier BV. - 0969-8051. ; 33:8, s. 1065-72
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to investigate the therapeutic efficacy and myelotoxicity during fractionated radioimmunotherapy of ovarian cancer in mice. The study was performed using the monoclonal antibody MX35 F(ab')(2) labeled with the alpha-particle emitter (211)At. METHODS: Animals were intraperitoneally inoculated with approximately 1x10(7) cells of the cell line NIH:OVCAR-3. Four weeks later, the mice were given the first treatment. Six groups of animals were intraperitoneally injected with approximately 800, 3x approximately 267, approximately 400, 3x approximately 133, approximately 50 or 3x approximately 17 kBq (211)At-MX35 F(ab')(2) (n=18 in each group). The second and third injections for Groups 2, 4 and 6 were given 4 and 8 days after the first injection, respectively. As controls, animals were treated with unlabeled MX35 F(ab')(2) (n=12). Eight weeks after the last injection, the animals were sacrificed and the presence of macro- and microscopic tumors and ascites was determined. Blood counts were determined for each mouse in Groups 1 and 2 before the first injection and 3, 7, 11, 15 and 23 days after the first injection. The calculation of the mean absorbed dose to the bone marrow was based on the ratio between the (211)At-activity concentration in bone and blood [i.e., the bone-to-blood ratio (BBLR)] as well as that between the (211)At-activity concentration in bone marrow and blood [i.e., the bone-marrow-to-blood ratio (BMBLR)] and the cumulated activity and absorbed fraction of the alpha-particles emitted by (211)At in the bone marrow. RESULTS: The tumor-free fractions of animals were 56% and 41% when treated with approximately 800 kBq and 3x approximately 267 kBq (211)At-MX35 F(ab')(2), respectively; 39% and 28% when treated with approximately 400 kBq and 3x approximately 133 kBq (211)At-MX35 F(ab')(2), respectively; and 17% and 22% when treated with approximately 50 kBq or 3x approximately 17 kBq (211)At-MX35 F(ab')(2), respectively. The nadir of the white blood cell (WBC) counts was decreased (from 46% to 19%, compared with the baseline WBC counts) and delayed (from Day 4 to Day 11 after the first injection) during the fractionated treatment compared with the single-dose treatment. The percentage of injected activity per gram (%IA/g) for blood, bone and bone marrow all peaked 6 h after injection at 13.80+/-1.34%IA/g, 4.00+/-0.69%IA/g and 8.28+/-1.38%IA/g, respectively. The BBLR and BMBLR were 0.20+/-0.04 and 0.58+/-0.01, respectively. The mean absorbed dose to bone marrow was approximately 0.4 Gy after intraperitoneally injecting approximately 800 kBq (211)At-MX35 F(ab')(2). CONCLUSION: No advantage was observed in the therapeutic efficacy of using a fractionated regimen compared with a single administration, with the same total amount of administered activity. Alleviation of the myelotoxicity was observed during the fractionated regimen in terms of decreased suppression and delayed nadir of the WBC counts. No thrombocytopenia was observed during either regimen.
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| 10. |
- Elgqvist, Jörgen, 1963, et al.
(författare)
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Intraperitoneal alpha-radioimmunotherapy in mice using different specific activities.
- 2009
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Ingår i: Cancer biotherapy & radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 24:4, s. 509-13
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to investigate the therapeutic efficacy of the alpha-radioimmunotherapy of ovarian cancer in mice, using different specific activities. This study was performed by using the monoclonal antibody, MX35 F(ab')(2), labeled with the alpha-particle-emitter, 211At. METHODS: Animals were intraperitoneally inoculated with approximately 1 x 10(7) cells of the cell line, NIH:OVCAR-3. Four (4) weeks later, five groups of animals were given 400 kBq of 211At-MX35 F(ab')(2) with specific activities equal to 130, 65, 32, 16, or 4 kBq/microg, respectively (n = 18 in each group). As controls, animals were given unlabeled MX35 F(ab')(2) (n = 12). Eight (8) weeks after treatment, the animals were sacrificed and the presence of macro- and microscopic tumors and ascites was determined. RESULTS: The tumor-free fractions (TFFs) of the animals, defined as the fraction of animals with no macro- and microtumors and no ascites, were 0.67, 0.73, 0.50, 0.50, and 0.17 when treated as above. Only the TFF of 0.17, for the specific activity of 4 kBq/microg, was significantly less, compared to that of the specific activity of 130 kBq/microg. The TFF for the specific activity of 4 kBq/microg showed a significant lowering, compared to the specific activity of 130 kBq/microg (p < 0.05). Treatment with unlabeled MX35 F(ab')(2) resulted in a TFF of zero. CONCLUSIONS: A specific activity-dependent therapeutic outcome could not be shown in the interval of 130- to 16 kBq/mug. For lower specific activities (i.e., 4 kBq/microg), the therapeutic efficacy was significantly lowered.
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