A phase I trial of humanized monoclonal antibody A33 in patients with colorectal carcinoma: biodistribution, pharmacokinetics, and quantitative tumor uptake.

PURPOSE: To determine the in vivo characteristics of huA33, a CDR-grafted humanized antibody against the A33 antigen, we have conducted an open-label, dose escalation, biopsy-based phase I trial of huA33 in patients with colorectal carcinoma. EXPERIMENTAL DESIGN: Patients with colorectal carcinoma were infused with [131I]huA33 (400 MBq: 10 mCi) and [125I]huA33 (40 MBq: 1 mCi) 1 week before surgery. There were four huA33 dose levels (0.25, 1.0, 5.0, and 10 mg/m2). Adverse events, pharmacokinetics, biodistribution, tumor biopsies, and immune responses to huA33 were evaluated. RESULTS: There were 12 patients entered into the trial (6 males and 6 females; age range, 39-66 years). No dose-limiting toxicity was observed. The biodistribution of huA33 showed excellent uptake of [131I]huA33 in metastatic colorectal carcinoma. Pharmacokinetic analysis showed no significant difference in terminal half-life (T1/2beta) between dose levels (mean +/- SD, 86.92 +/- 22.12 hours). Modeling of colon uptake of huA33 showed a T1/2 of elimination of 32.4 +/- 8.1 hours. Quantitative tumor uptake ranged from 2.1 x 10(-3) to 11.1 x 10(-3) %ID/g, and tumor/normal tissue and tumor/serum ratios reached as high as 16.3:1 and 4.5:1, respectively. Biosensor analysis detected low-level human anti-human antibody responses in four patients following huA33 infusion. CONCLUSIONS: huA33 shows selective and rapid localization to colorectal carcinoma in vivo and penetrates to the center of large necrotic tumors, and colon elimination half-life of huA33 is equivalent to basal colonocyte turnover. The excellent targeting characteristics of this humanized antibody indicate potential for the targeted therapy of metastatic colorectal cancer in future trials.     

A phase I trial of humanized monoclonal antibody HuM195 (anti-CD33) with low-dose interleukin 2 in acute myelogenous leukemia.

HuM195 is a recombinant humanized IgG1 monoclonal antibody reactive with CD33, a Mr 67,000 glycoprotein expressed on early myeloid progenitor cells and myeloid leukemia cells. HuM195 has been shown to rapidly target and saturate acute myeloid leukemia (AML) cells after i.v. infusion into patients and is capable of mediating antibody-dependent cellular cytotoxicity. This activity is enhanced in vitro when natural killer (NK) effector cells are preincubated with low concentrations of interleukin 2 (IL-2). Previous Phase I trials of HuM195 in patients with relapsed AML demonstrated safety and attainment of complete responses, but significant antileukemic activity appears limited to patients with low leukemia tumor burdens. Therefore, in the present trial, we sought to determine whether low-dose IL-2 could safely enhance the numbers of NK cells and therefore the cytotoxic capability of HuM195 via presumptive NK cell antibody-dependent cellular cytotoxicity in vivo against myeloid leukemia cells. Thirteen patients with relapsed or refractory AML and one patient with advanced myelodysplastic syndrome were treated with 0.6x10(6) IU/m2 of s.c. IL-2 daily for 35 days. Starting on day 15, patients received twice weekly i.v. infusions of HuM195 (3.0 mg/m2) for 3 weeks. Immediately after the HuM195 infusion, the patients received IL-2 i.v. infusions over 2 h at one of three escalating dose levels of 0.5x10(6), 1.0x10(6), and 2.0x10(6) IU/m2. Peripheral blood mononuclear cells were quantitated and immunophenotyped by flow cytometry. Safety, tolerability, bone marrow mononuclear cell morphology, and immunophenotype, as well as responses were assessed. Of the 14 patients who entered the study, 10 were able to complete at least one cycle of therapy. Adverse effects to the s.c. IL-2 were relatively mild and included erythema and induration of the skin at the injection site and low-grade fever. Toxicity from the sequential HuM195 and i.v. IL-2 infusions included nausea, rigors, and fever. Toxicity was IL-2 dose related with dose-limiting toxicity seen at the 2.0x10(6) IU/m2 dose level. Three patients had stable disease at the completion of the first cycle and went on to receive a second cycle of treatment. CD3-positive, CD56-positive, and CD33-positive cells were generally found to significantly decrease immediately after each administration of i.v. IL-2 and HuM195. CD56-expressing cells increased in 6 of 10 patients from the beginning to the end of therapy. Among the 10 evaluable patients, 2 patients had significant decreases in the percentage of blasts in the bone marrow (one of which achieved a complete bone marrow remission), 5 patients had stable levels of bone marrow blasts, and 3 had progression of disease on therapy. The combination of IL-2 and HuM195 shows modest biological activity and clinical antileukemic activity but also produced significant toxicity.     

Biodistribution of 211At-labeled humanized monoclonal antibody A33

Radioimmunotherapy (RIT) could be a possible adjuvant treatment method for patients with colorectal carcinoma. The A33 antigen is a promising RIT target, as it is highly and homogenously expressed in 95% of all colorectal carcinomas. In this study, the humanized monoclonal antibody A33 (huA33), targeting the A33 antigen, was labeled with the therapeutic nuclide 211At, and the biodistribution and in vivo targeting ability of the conjugate was investigated in an athymic mouse xenograft model. There was an accumulation of 211At in tumor tissue over time, but no substantial accumulation was seen in any organ apart from the skin and thyroid, indicating no major release of free 211At in vivo. At all time points, the uptake of 211At-huA33 was higher in tumor tissue than in most organs, and at 8 hours postinjection (p.i.), no organ had a higher uptake than tumor tissue. The tumor-to-blood ratio of 211At-huA33 increased with time, reaching 2.5 after 21 hours p.i. The highest absorbed dose was found in the blood, but the tumor received a higher dose than any organ other than the thyroid. An in vivo blocking experiment showed that 211At-huA33 binds specifically to human tumor xenografts in athymic mice. In conclusion, the favorable biodistribution and specific in vivo targeting ability of 211At-huA33 makes it a potential therapeutic agent for the RIT of metastatic colorectal carcinoma.     

Serological analysis of human anti-human antibody responses in colon cancer patients treated with repeated doses of humanized monoclonal antibody A33

Mouse monoclonal antibody A33 (mAb A33) recognizes a M(r) 43,000 cell surface glycoprotein (designated A33) expressed in human colonic epithelium and colon cancer but absent from most other normal tissues. In patients, mAb A33 localizes with high specificity to colon cancer and is retained for up to 6 weeks in the cancer but cleared rapidly from normal colon (5-6 days). As a carrier of (125)I or (131)I, mAb A33 has shown antitumor activity. Induction of strong human anti-mouse antibody (immunoglobulin; HAMA) responses in patients, however, limits the use of the murine mAb A33 to very few injections. A humanized version of this antibody (huAb A33) has been prepared for Phase I and II clinical studies in patients with colon cancer. In those studies, immunogenicity of huAb A33 has been monitored using a novel, highly sensitive BIACORE method, which allows measurement of human anti-human antibodies (HAHAs) without the use of secondary reagents. We found that 63% (26 of 41) of the patients treated with repeated doses of huAb A33 developed HAHAs against a conformational antigenic determinant located in the V(L) and V(H) regions of huAb A33. Detailed serological analysis showed two distinct types of HAHAs. HAHA of type I (49% of patients) was characterized by an early onset with peak HAHA levels after 2 weeks of treatment, which declined with ongoing huAb A33 treatment. HAHA of type II (17% of patients) was characterized by a typically later onset of HAHA than in type I and by progressively increasing HAHA levels with each subsequent huAb A33 administration. Colon cancer patients with type I HAHAs did not develop infusion-related adverse events. In contrast, HAHA of type II was indicative of infusion-related adverse events. By using this new method, we were able to distinguish these two types of HAHAs in patients while on antibody treatment, allowing patients to be removed from study prior to the onset of severe infusion-related adverse events.     

Phase I study of anticolon cancer humanized antibody A33.

PURPOSE: Humanized A33 (huA33; IgG1) monoclonal antibody detects a determinant expressed by 95% of colorectal cancers and can activate immune cytolytic mechanisms. The present study was designed to (a) define the toxicities and maximum tolerated dose of huA33 and (b) determine huA33 immunogenicity. EXPERIMENTAL DESIGN: Patients (n = 11) with advanced chemotherapy-resistant colorectal cancer received 4-week cycles of huA33 at 10, 25, or 50 mg/m(2)/week. Serum samples were analyzed using biosensor technology for evidence of human antihuman antibody (HAHA) response. RESULTS: Eight of 11 patients developed a HAHA response. Significant toxicity was limited to four patients who developed high HAHA titers. In two of these cases, infusion-related reactions such as fevers, rigors, facial flushing, and changes in blood pressure were observed, whereas in the other two cases, toxicity consisted of skin rash, fever, or myalgia. Of three patients who remained HAHA negative, one achieved a radiographic partial response, with reduction of serum carcinoembryonic antigen from 80 to 3 ng/ml. Four patients had radiographic evidence of stable disease (2, 4, 6, and 12 months), with significant reductions (>25%) in serum carcinoembryonic antigen levels in two cases. CONCLUSIONS: The complementarity-determining region-grafted huA33 antibody is immunogenic in the majority of colon cancer patients (73%). HAHA activity can be measured reproducibly and quantitatively by BIACORE analysis. Whereas the huA33 construct tested here may be too immunogenic for further clinical development, the antitumor effects observed in the absence of antibody-mediated toxicity and in this heavily pretreated patient population warrant clinical testing of other IgG1 humanized versions of A33 antibody.     

A phase I biodistribution and pharmacokinetic trial of humanized monoclonal antibody Hu3s193 in patients with advanced epithelial cancers that express the Lewis-Y antigen.

PURPOSE: We report a first-in-man trial of a humanized antibody (hu3S193) against the Le(y) antigen. EXPERIMENTAL DESIGN: Patients with advanced Le(y)-positive cancers received four infusions of hu3S193 at weekly intervals, with four dose levels (5, 10, 20, and 40 mg/m(2)). The first infusion of hu3S193 was trace labeled with Indium-111, and biodistribution, pharmacokinetics, tumor uptake, and immune response were evaluated in all patients. RESULTS: A total of 15 patients (7 male/8 female; age range, 42-76 years; 6 breast, 8 colorectal cancer, and 1 non-small-cell lung cancer) were entered into the study. Transient grade 1 to 2 nausea and vomiting was observed following infusion of hu3S193 at the 40 mg/m(2) dose level only. There was one episode of dose-limiting toxicity with self-limiting Common Toxicity Criteria grade 3 elevated alkaline phosphatase observed in one patient with extensive liver metastases. The biodistribution of (111)In-hu3S193 showed no evidence of any consistent normal tissue uptake, and (111)In-hu3S193 uptake was observed in cutaneous, lymph node, and hepatic metastases. Hu3S193 displayed a long serum half-life (T(1/2)beta = 189.63 +/- 62.17 h). Clinical responses consisted of 4 patients with stable disease and 11 patients with progressive disease, although one patient experienced a 89% decrease in a lymph node mass, and one patient experienced inflammatory symptoms in cutaneous metastases, suggestive of a biological effect of hu3S193. No immune responses (human anti-human antibody) to hu3S193 were observed. CONCLUSION: Hu3S193 is well tolerated and selectively targets tumors, and the long half-life and biological function in vivo of this antibody makes it an attractive potential therapy for patients with Le(y)-expressing cancers.     

Preliminary report of a phase I study of combination chemotherapy and humanized A33 antibody immunotherapy in patients with advanced colorectal cancer.

PURPOSE: In previous studies, humanized A33 (huA33) demonstrated modest antitumor activity in chemotherapy-resistant colorectal cancer patients. In addition, unexpected major tumor responses were observed in patients treated with a specific chemotherapy regimen [carmustine, vincristine, fluorouracil, and streptozocin (BOF-Strep)] administered after huA33 protocols. We designed the present Phase I, open label, cohort, dose-escalation study of huA33 and a fixed dose of BOF-Strep to (a) determine the maximum tolerated dose of huA33 immunotherapy administered with chemotherapy, (b) determine whether chemotherapy modifies huA33 immunogenicity, and (c) develop preliminary information regarding antitumor activity. EXPERIMENTAL DESIGN: Stage IV fluorouracil/leucovorin and irinotecan-refractory colorectal cancer patients (n = 16) received escalating weekly doses of huA33 (5-40 mg/m(2)) with BOF-Strep chemotherapy. RESULTS: Four patients requiring radiotherapy or surgery were removed early. Of 12 evaluable patients, grade 3 and 4 neutropenia (n = 2) and grade 3 thrombocytopenia (n = 1) were observed. Seven of 12 (58.3%) patients developed anti-huA33 activity. Three patients had radiographic partial responses for 7.5, 5.5, and 14 months with greater than 85% decline in serum carcinoembryonic antigen levels. One mixed response (4.5 months with a serum carcinoembryonic antigen decline of 38%) was also observed. CONCLUSIONS: huA33 can be safely combined with BOF-Strep chemotherapy. The present report provides compelling evidence supporting our previous observations of major antitumor activity with the combination of huA33 and BOF-Strep chemotherapy. huA33 is still immunogenic when administered with chemotherapy. Future studies to evaluate the immunogenicity of new huA33 antibodies and identify which drugs in the BOF-Strep regimen are critical for enhanced antitumor efficacy are planned.     

A phase II trial of chimeric monoclonal antibody G250 for advanced renal cell carcinoma patients

Chimeric monoclonal antibody G250 (WX-G250) binds to a cell surface antigen found on >90% of renal cell carcinoma (RCC). A multicentre phase II study was performed to evaluate the safety and efficacy of WX-G250 in metastatic RCC (mRCC) patients. In all, 36 patients with mRCC were included. WX-G250 was given weekly by intravenous infusion for 12 weeks. Patients with stable disease (SD) or response were eligible to receive additional treatment for 8 weeks. None of the 36 enrolled patients experienced any drug-related grade III or IV toxicity. Only three patients had grade II toxicity possibly related to the study medication. In all, 10 patients had SD and received extended treatment. One complete response and a significant regression was observed during the follow-up of the treatment. Five patients with progressive disease at study entry were stable for more than 6 months after study entry. The median survival after treatment start was 15 months. The weekly schedule of WX-G250 was well tolerated. With a median survival of 15 months after the start of this treatment and two late clinical responses, WX-G250 seems to be able to modulate mRCC. To improve the activity of WX-G250-specific antibody-dependent cellular cytotoxicity and the clinical response rate, currently combinations of WX-G250 with cytokines are in phase II trials.     

抗表皮生长因子受体单克隆抗体h-R3联合放疗治疗晚期鼻咽癌的Ⅱ期临床研究

目的观察h-R3与放疗联合治疗晚期鼻咽癌的疗效和不良反应。方法采用随机对照设计,共7个治疗中心参加了这项研究。符合入组标准的晚期鼻咽癌患者随机分为单放组和联合治疗组,两组患者均接受单纯根治性放射治疗,总剂量70—76 Gy.联合治疗组同时给予h—R3治疗,剂量为100 mg/次,静脉滴注,每周给药1次。结果共137例患者入组,其中单放组67例,联合治疗组70例。联合治疗组治疗结束、治疗后第5周和第17周时的肿瘤完全缓解(CR)率,在全分析集(ITT集)分别为65.63%、87.50%和90.63%,在符合方案集(PP集)分别为67.21%、90.16%和93.44%,均显著高于单放组。联合治疗组治疗后第17周时,在ITT集和PP集的有效率均为100.00%,均显著高于单放组(90.91%和92.31%)。治疗前后两组间Karnofsky评分差异无统计学意义,联合治疗组患者体重恢复情况明显好于单放组。与h-R3相关的主要不良反应是发热(4.28%)、血压下降(2.86%)、恶心(1.43%)、头晕(2.86%)、皮疹(1.43%)。h-R3对血常规和生化指标无显著影响,并且未增加放疗的副作用。结论h-R3联合放疗可显著提高晚期鼻咽鳞癌患者的疗效,药物不良反应轻微,对治疗晚期鼻咽癌有很高的临床应用价值。     

Japanese phase I study of GC33, a humanized antibody against glypican‐3 for advanced hepatocellular carcinoma

GC33 is a humanized mAb against human glypican-3 (GPC3). In the first-in-human study carried out in the USA, GC33 was well tolerated and showed preliminary antitumor activity in patients with advanced hepatocellular carcinoma. This study aimed to assess the safety, tolerability, and pharmacokinetic characteristics of GC33 in Japanese patients with advanced hepatocellular carcinoma. The study design was a conventional 3 + 3 dose-escalation design to determine the maximum tolerated dose of GC33 given i.v. at 5, 10, or 20 mg/kg weekly. Immunohistochemistry was carried out on tumor biopsies to evaluate GPC3 expression. Thirteen patients were enrolled across the three dose levels, and no patients observed any dose-limiting toxicity up to the highest planned dose of 20 mg/kg. The most common adverse events were decreased lymphocyte count, decreased natural killer cell count, increased C-reactive protein, and pyrexia. Grade 3 adverse events (increased blood pressure, decreased lymphocyte count, and decreased platelet count) were observed in two or more patients. The AUC_inf showed a dose-proportional increase from the 5 mg/kg dose group to the 20 mg/kg dose group. The trough concentrations of GC33 appeared to reach a steady state after the fourth to the sixth dose. Seven of the 13 patients showed stable disease, the other six showed progressive disease. Furthermore, three patients showed long-term stable disease of more than 5 months. In conclusion, GC33 given at up to 20 mg/kg weekly was well tolerated in Japanese patients with advanced hepatocellular carcinoma.     

Phase I radioimmunotherapy trial with iodine-131--labeled humanized MN-14 anti-carcinoembryonic antigen monoclonal antibody in patients with metastatic gastrointestinal and colorectal cancer

This trial was conducted to determine the pharmacokinetics, dosimetry, dose-limiting toxicity, and the maximum tolerated dose of iodine-131 humanized MN-14 immunoglobulin G (131I-hMN-14 IgG), a humanized complementary-determining region-grafted anti-carcinoembryonic antigen monoclonal antibody, in metastatic gastrointestinal and colorectal cancer patients. Patients were divided into 2 groups: group A consisted of patients who had prior external beam radiation therapy (n = 8), and group B included patients who had received standard chemotherapy (n = 13). All patients received a diagnostic infusion of 131I-hMN-14 IgG (approximately 8.0 mCi, 15 mg/m2) to study the pharmacokinetics, biodistribution, and dosimetry. One week later, 17 of 21 patients received infusional therapy of escalating radioactive doses of 131I-hMN-14 IgG. Blood pharmacokinetics and quantitative imaging were performed again after the therapeutic dose. Radiation-absorbed doses to normal organs and tumors were determined by MIRDOSE-3 algorithms. The primary dose-limiting toxicity was hematologic toxicity at 40 mCi/m2. The blood half-life (n = 20) was identical for the diagnostic and therapy infusions. The mean red marrow dose was 2.2 +/- 2.4 cGy/mCi. The mean tumor radiation dose (n = 8) was 24.2 +/- 22.6 cGy/mCi. Tumor targeting was seen in most large metastatic lesions. No objective responses were seen in these heavily pretreated and mostly advanced patients. In conclusion, 131I-hMN-14 IgG has good targeting, good tumor to normal organs radiation absorbed ratios, and an acceptable toxicity profile in advanced metastatic gastrointestinal and colorectal cancer patients.     

Quantitative analysis of antibody localization in human metastatic colon cancer: a phase I study of monoclonal antibody A33

A33 is a mouse immunoglobulin G2a (IgG2a) monoclonal antibody (mAb) that detects a heat-stable, protease- and neuraminidase-resistant epitope. The antigen is homogeneously expressed by virtually all colon cancers and in the colon mucosa but not other epithelial tissues. The biodistribution and imaging characteristics of iodine-131 (131I)-mAbA33 were studied in colorectal carcinoma patients with hepatic metastases. Antibody labeled with 2 to 5 mCi of 131I was administered intravenously (IV) 7 to 8 days before surgery at five dose levels, ranging from 0.2 mg to 50 mg, with three or more patients entered at each dose level. In addition, three patients received 2 mg 131I-mAbTA99 (an isotype-matched control mAb) together with 125I-mAbA33. Evaluation included whole-body imaging with a gamma camera, technetium-99 (99mTc)-human serum albumin blood pool scans, liver/spleen scans, abdominal computed tomographic (CT) scans, hepatic arteriograms, antibody pharmacokinetics, and assessment of antibody distribution in biopsied malignant and normal tissues. Selective mAbA33 localization to tumor tissue was demonstrated in 19 of 20 patients, and external imaging correlated with surgical inspection, pathologic examination, and tissue radioactivity. One week after antibody administration, tumor:liver ratios ranged from 6.9:1 to 100:1 and tumor:serum ratios from 4.1:1 to 25.2:1. 99mTc-albumin blood pool studies showed that liver metastases were hypovascular, emphasizing the selective localization of mAbA33 despite poor tumor-blood flow. Control mAbTA99 studies showed mAbA33 localization was antigen-specific; tumor:liver ratios were 2.3- to 45-fold higher for specific antibody. In metastatic lesions, radioisotope was localized primarily in the viable periphery; however, even the necrotic tumor core concentrated specific antibody. External imaging showed isotope visualization in some patients' large bowel; whether this represents specific antibody uptake or gastric iodine secretion is unclear.     

Phase I trial of 131I-huA33 in patients with advanced colorectal carcinoma.

PURPOSE: Humanized monoclonal antibody A33 (huA33) targets the A33 antigen which is expressed on 95% of colorectal cancers. A previous study has shown excellent tumor-targeting of iodine-131 labeled huA33 (131I-huA33). Therefore, we did a phase I dose escalation trial of 131I-huA33 radioimmunotherapy.Experimental Designs: Fifteen patients with pretreated metastatic colorectal carcinoma each received two i.v. doses of 131I-huA33. The first was an outpatient trace-labeled "scout" dose for biodistribution assessment, followed by a second "therapy" dose. Three patients were treated at 20, 30, and 40 mCi/m2 dose levels, and six patients at 50 mCi/m2 to define the maximum tolerated dose. RESULTS: Hematologic toxicity was 131I dose-dependent, with one episode of grade 4 neutropenia and two episodes of grade 3 thrombocytopenia observed at 50 mCi/m2. The maximum tolerated dose was determined to be 40 mCi/m2. There were no acute infusion-related adverse events, and gastrointestinal toxicity was not observed despite uptake of 131I-huA33 in bowel. Seven patients developed pruritus or rash, which was not related to 131I dose. There was excellent tumor-targeting of 131I-huA33 shown in all patients. The serum T1/2beta of 131I-huA33 was (mean +/- SD) 135.2 +/- 46.9 hours. The mean absorbed tumor dose was 6.49 +/- 2.47 Gy/GBq. Four patients developed human anti-human antibodies. At restaging, 4 patients had stable disease, whereas 11 patients had progressive disease. CONCLUSION: Radioimmunotherapy using 131I-huA33 shows promise in targeting colorectal tumors, and is deliverable at a maximum tolerated dose of 40 mCi/m2. Further studies of 131I-huA33 in combination with chemotherapy are planned.     

High-dose therapy with 90Yttrium-labeled monoclonal antibody CC49: a phase I trial.

A Phase I trial of increasing administered activities of 90yttrium (90Y)-labeled monoclonal antibody (MAb) CC49 was conducted to determine whether extrahematopoietic toxicity occurred with this radioimmunoconjugate. Twelve patients with various gastrointestinal tract cancers were administered a tracer dose of 111In-labeled MAb CC49 for biodistribution and pharmacokinetic studies. Patients then underwent a single treatment with increasing administered activities of 90Y-labeled MAb CC49 (0.3, 0.4, and 0.5 mCi/kg). Biodistribution studies, using 111In-labeled MAb CC49 as a surrogate, were determined using planar and single photon emission computed tomography imaging. Pharmacokinetic studies were performed by measuring radioactivity in blood samples taken at intervals after radioimmunoconjugate infusions. Tissue biopsies of tumor metastases and related normal tissues (liver and bone marrow) were obtained for radioactivity measurements. Radiation dosimetry estimates were calculated using these data. Toxicity was evaluated using the National Cancer Institute Common Toxicity Criteria. No dose limiting extrahematopoietic toxicity was identified in the range of administered activities used in this study. Radioimmunolocalization based on planar and single photon emission computed tomography images 111In-labeled MAb CC49 showed heterogeneous (nonspecific) liver and splenic uptake. Liver metastases were usually photopenic, and extrahepatic metastases showed faint to moderate uptake. The alpha and beta half-lives of 111In-labeled MAb CC49 and 90Y-labeled MAb CC49 in the blood were similar. Absorbed radiation dose estimates in metastatic tumor sites ranged from 180 to 3000 cGy. The percentage of injected dose/kg of tumor ranged from 1.12 to 18.14; however, tumor:normal liver ratios were consistently <1. No objective responses were observed. Doses of up to 0.5 mCi/kg could be administered with reversible grade IV myelotoxicity. Absorbed radiation dose in tumor was suboptimal, even at the highest administered activity level. Deposition of 90Y in liver was high, and estimates of absorbed dose in liver equaled or exceeded that which could be achieved in metastatic tumor sites. Strategies to enhance access of radioimmunoconjugates in tumor and diminish deposition in the liver need to be developed for effective treatment using MAb CC49 with chelated radiometals.     

Treatment of relapsed or refractory acute myeloid leukemia with humanized anti-CD33 monoclonal antibody HuM195.

HuM195 is a humanized, unconjugated, anti-CD33 monoclonal antibody. Fifty adult patients with relapsed or refractory AML were randomized to receive HuM195 at a dose of 12 or 36 mg/m(2) by intravenous infusion over 4 h on days 1-4 and 15-18. Patients with stable or responding disease received two additional cycles on days 29-32 and 43-46. HuM195 was given as first salvage therapy in 24 patients and as second or subsequent salvage therapy in 26 patients. Pretreatment blast percentage in the marrow was between 5 and 30% in 20 patients with the others having blast counts greater than 30%. The median age of patients was 62 years (range 26-86) and CD33 was detected in 95% of patients for whom immunophenotyping was available. Of 49 evaluable patients, two complete and one partial remission were observed. All three responses were in patients treated at the 12 mg/m(2) dose level and all had baseline blast percentages less than 30%. Decreases in blast counts ranging from 30 to 74% were seen in nine additional patients. Infusion-related events of fever and chills occurred in the majority of patients and were generally mild and primarily related to the first dose of antibody. No hepatic, renal or cardiac toxicities were observed and other adverse events such as nausea, vomiting, mucositis and diarrhea were uncommon or felt to be unrelated to HuM195. In addition, anti-HuM195 responses were not detected. HuM195 as a single agent has minimal, but observable, anti-leukemic activity in patients with relapsed or refractory AML and activity is confined to patients with low burden disease. No significant differences in clinical efficacy or toxicity were seen between the two dose levels of antibody. HuM195 was well tolerated with infusion-related fevers and chills the predominant toxicities seen. Meaningful clinical efficacy of this unconjugated monoclonal antibody may be realized only in patients with minimal residual disease, or in combination with chemotherapy.     

A phase I/II trial of docetaxel and oxaliplatin in patients with advanced gastric cancer

Purpose  We designed this phase I/II study of docetaxel–oxaliplatin combination chemotherapy to determine the dose-limiting toxicity (DLT), maximum tolerated dose and efficacy as a first-line treatment in patients with advanced gastric cancer. Methods  Patients with histologically proven, chemo-naive gastric adenocarcinoma were eligible. For the phase I part, three dose levels of oxaliplatin and docetaxel every 3 weeks were tested in a cohort of three patients for each level (respectively, 100 and 60 mg/m², 100 and 75 mg/m², 130 and 75 mg/m²). Patients were treated up to a maximum of nine cycles of oxaliplatin and docetaxel unless there was documented disease progression, an unacceptable adverse event, or withdrawal of consent. Results  No DLT was observed at any of the three levels tested in the phase I portion. Therefore, oxaliplatin 130 mg/m² and docetaxel 75 mg/m² were recommended for the phase II study. All 47 patients were evaluable for toxicity and treatment response. The overall response rate was 55.3% (95% CI, 40.6–70.1%) and median duration of response was 4.2 months (range 0.9–9.5 months). After a median follow-up duration of 13.3 months, median overall survival was 12.7 months (95% CI: 10.4–14.9). The median time to progression was 5.0 months (95% CI, 3.4–6.5 months). The main toxicities (grade 3 or 4) were febrile neutropenia (14.9%), neutropenia (23.4%), diarrhea (10.6%) and neurotoxicity (8.5%). Conclusion  The combination of docetaxel and oxaliplatin was feasible with favorable toxicity profile and showed a promising anti-tumor activity in unresectable, metastatic gastric cancer patients.     

Kinetics, quantitative analysis and radioimmunolocalization using indium-111-HMFG1 monoclonal antibody in patients with breast cancer

HMFG1 tumour associated monoclonal antibody IgG1 and F(ab')2 fragments were radiolabelled with indium-111 and used to study patients with breast cancer. In vitro and in vivo stability of the radiolabelled antibodies was shown to be satisfactory. Thirty patients with primary breast cancer underwent tumour resection and quantitative evaluation of the radioactivity in the tumour and normal tissues following administration of specific and non-specific antibodies. The mean tumour uptake of HMFG1 F(ab')2 fragments at 24 h was significantly higher (P less than 0.05) than the intact IgG but at 48 h there was no difference. The mean tumour uptake with the specific antibody was higher than the non-specific antibody of the same subclass (P less than 0.05). Lymph node metastases showed higher antibody uptake than the corresponding primary tumours (P less than 0.05). Fifteen patients with primary or metastatic breast cancer were investigated by external body scintigraphy using HMFG1 F(ab')2 fragments. Successful localisation was observed in approximately 50% of the primary and metastatic lesions with no false positive results. All the patients had observable concentration of 111In in the liver (20% of the injected dose), the kidneys and the spleen. Following i.v. administration, F(ab')2 fragments cleared from the blood more rapidly than the intact IgG. We conclude that HMFG1 F(ab')2 fragments can localise specifically and faster than intact IgG in breast cancer but the sensitivity of the radioimmunoscintigraphy is relatively low. This method needs further improvement before becoming clinically useful for detecting and staging breast cancer.     

A phase I clinical trial utilizing autologous tumor-infiltrating lymphocytes in patients with primary hepatocellular carcinoma

This report describes an ongoing Phase I clinical trial testing the safety of adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TIL) in patients with primary hepatocellular carcinoma (HCC). Fifteen HCC patients were treated with their activated and expanded TILs following tumor resection. From a total of 17 patients with HCC, TIL were successfully expanded from 15 patients (88%), whereas two patients showed minimal or no expansion of TIL. Transient increase in the frequency of T cells was observed after adoptive transfer who was found only associated with grade I flu-like symptoms and malaise. After a median follow-up of 14 months, 15 patients (100%) were alive; and 12 patients (80%) showed no evidence of disease, 3 patients (patient 1,11,12) had tumor recurrence. The time to the diagnosis of tumor recurrence following therapy ranged from 105 to 261 days. These results indicate that immunotherapy with activated and expanded autologous TIL could be successfully performed with low toxicity, thus would serve as a novel treatment modality for patients with HCC.     

A phase 1a clinical trial of LYM-1 monoclonal antibody serotherapy in patients with refractory B cell malignancies

Ten patients with refractory B cell lymphomas were treated with weekly intravenous infusions of escalating doses of murine monoclonal antibody (MoAb) LYM-1 over four weeks. LYM-1 is a recently developed IgG2a murine MoAb that recognizes a polymorphic HLA-Dr antigen on surfaces of normal and malignant B cells but does not bind to any other normal tissues. MoAb LYM-1 has several advantages for serotherapy, since the antigen it recognizes is not shed from the cell surface and does not modulate in response to MoAb therapy. Furthermore, in vitro studies have indicated significant anti-tumour activity against lymphoma cell lines. In the current trial, dose-dependent levels of free LYM-1 were detected in the serum of all patients, but penetration of extravascular tumour tissues was poor. No significant toxicity or human anti-mouse antibody responses were observed in any patient. Clinical responses were minor and appeared to correlate with the number of infiltrating T cells seen in the initial lymphoma specimens. LYM-1 appears to be well-tolerated and has demonstrated several potential advantages as a therapeutic agent in patients with lymphoma. The mechanism of anti-tumour effect and plans for further clinical studies are discussed.     

Radioimmunoscintigraphy of human gastric carcinoma xenografts with 125I-labeled monoclonal antibody

A monoclonal antibody (GC 302) established in our laboratory, which was reactive with gastric carcinoma and other epithelial carcinoma but not with normal gastric mucosa or other malignant tumors of mesenchymal origin, was used to investigate the radioimmunolocalization of tumors. Various kinds of target cells (5 X 10(5)) were incubated with 125I-labeled GC 302, and radioactivity was determined with a gamma counter. It was shown that there was a 500- to 1,000-fold increase in counts for gastric carcinoma (NUGC-2, NUGC-4, MKN-28 and MKN-45) as compared to those of normal lymphocytes and about 100-fold increase as compared to melanoma or leukemia. These findings were consistent with those obtained from the study of immunohistochemistry using GC 302. An in vitro assay was also carried out using nude mice bearing gastric cancer and inoculated with 125I-labeled GC 302. There was a 2- to 3-fold increase in radioactivity in the tumor and a 4- to 5-fold increase as compared with the visceral organs. Although the tumor:blood ratio was relatively low, radioimmunoscintigraphy could be done successfully with the aid of computed radiography. We thus conclude that further testing of GC 302 is worthwhile to establish whether or not it is useful for radioimmunoscintigraphy of metastatic lesions of gastric cancer for possible clinical application.