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Biomedical subjects

A F LoBuglio

Publications and source records attributed to A F LoBuglio.

At least 37 records · Page 2Linked to original sources

Correlation of toxicity with treatment parameters for 131I-CC49 radioimmunotherapy in three phase II clinical trials.

Analyses were performed on 40 patients with TAG-72 expressing metastatic cancer who were entered into three phase II clinical trials. The dose selected was the maximum tolerated dose in phase I studies. Patients all had unresectable metastatic colon or prostate cancer and had recovered from prior therapies. Patients in trials #1 and #2 received 75 mCi/m2 131I-CC49 antibody whereas those in trial #3 received a total of 75 mCi/m2 with equal amounts of 131I-CC49 and 131I-COL-1. The three trials have resulted in a reproducible degree of reversible marrow suppression; 72.5% of patients experienced moderate or severe toxicity. Comparisons were made between demographic, clinical and pharmacokinetical variables and the grade of WBC toxicity, platelet toxicity and the sum of the two as total toxicity. Whole body radiation dose had a statistically significant relationship with platelet toxicity (r = 0.38, p = 0.015) and total toxicity (r = 0.34, p = 0.035). The bone marrow radiation dose is significantly related to all toxicity indicators with correlation coefficients with WBC and platelet toxicities of 0.47 (p = 0.002) and 0.34 (p = 0.033), respectively. Plasma half-life had the strongest correlation with WBC toxicity and combined toxicities. Multivariate models were developed to help describe the simultaneous effect of these variables on toxicity. The results show that the MTD dose was safely given to patients who varied in age, disease burden and degree of marrow compromise. This supports the contention that a fixed dose of radiolabeled antibody per body mass or m2 can be given to a diverse group of non-lymphoma patients with a predictable toxicity range.

Adult↗

Recent progress in radioimmunotherapy for cancer.

Radioimmunotherapy allows for the delivery of systemically targeted radiation to areas of disease while relatively sparing normal tissues. Despite numerous challenges, considerable progress has been made in the application of radioimmunotherapy to a wide variety of human malignancies. The greatest successes have occurred in the treatment of hematologic malignancies. Radioimmunotherapy, with or without stem-cell transplant support, has produced substantial complete remission rates in chemotherapy-resistant B-cell lymphomas. Nonmyeloablative regimens have shown so much promise that they are now being tested as initial therapy for low-grade B-cell lymphomas. Although solid tumor malignancies have been less responsive to radioimmunotherapy, encouraging results have been obtained with locoregional routes of administrations, especially when the tumor burden is small. Greater tumor-to-normal tissue ratios are achievable with regional administration. Even with intraperitoneal and intrathecal administration, bone marrow suppression remains the dose-limiting toxicity. Ongoing research into new targeting molecules, improved chelation chemistry, and novel isotope utilization is likely to extend the applications of this strategy to other tumor types. The potential for radioimmunotherapy will be enhanced if this modality can be optimally adapted for integration with other agents and if the administration method can be tailored to the type and distribution of malignancy.

Hematologic Neoplasms↗

Polynucleotide-mediated immunization therapy of cancer.

The novel observations that intramuscular injection of plasmid DNA preparations could result in myocyte gene expression and induce immune responses to encoded immunogens has generated intense interest in the form of gene therapy. This phenomena can occur with both DNA and RNA reagents, and can be used in immune protection (vaccine) or therapy strategies. Immunization with DNA plasmids has generated protective immunity to a wide variety of pathogens and tumor cells in murine animal models. Immune response has occurred in a broad range of animal species following intramuscular injection of plasmid DNA encoding various immunogens as well as following other routes of administration (intravenous, intradermal, etc). The mechanisms responsible for induction of the immune response are as yet unclear, but responses include antibody production, T-cell proliferation, lymphokine release, generation of cytolytic T cells, and delayed hypersensitivity reactions. Plasmid DNA production and purification methods are relatively easy to standardize, and dual expressing plasmids allow incorporation of immune enhancement molecules or second immunogens. Plasmid DNA encoding nontransforming tumor-associated antigens are in development with a National Institutes of Health-approved protocol for carcinoembryonic antigen in colorectal cancer patients. Transforming tumor-associated antigens (eg, HER2/neu) may be approached with RNA or replicative RNA constructs for immunization. The efficacy of this immune approach will soon be examined in clinical trials in patients with cancer and the acquired immunodeficiency syndrome.

Animals↗

Intraperitoneal radioimmunotherapy of ovarian cancer with lutetium-177-CC49.

UNLABELLED: Twelve ovarian cancer patients who failed chemotherapy entered a Phase I trial of intraperitoneal 177Lu-CC49 antibody. METHODS: Patients had disease confined to the abdominal cavity +/- retroperitoneal lymph nodes, adequate organ function and no previous radiation. RESULTS: Side effects included mild discomfort with administration (1/12), delayed transient arthralgia (2/12), and mild marrow suppression (calculated marrow doses of 11-54 cGy). The maximum tolerated dose has not been reached with levels of 10, 18, 25 and 30 mCi/m2. Radioimmunoscintigraphy revealed localization consistent with tumor in 11 of 12 patients. One of eight patients with gross disease had > 50% tumor reduction after therapy, while six progressed and one went off study with stable disease. Of patients with microscopic or occult disease, one relapsed at 10 mo and three remain without evidence of disease after 18 mo. CONCLUSION: Intraperitoneal radioimmunotherapy with 177Lu-CC49 is well tolerated and appears to have antitumor activity against chemotherapy-resistant ovarian cancer in the peritoneal cavity.

Adenocarcinoma↗

Selected strategies to augment polynucleotide immunization.

We sought to amplify the immune response to polynucleotide immunization through co-delivery of complementary DNA (cDNA) encoding a cytokine or co-stimulatory molecule to enhance antigen presentation. In the context of intramuscular immunization, we examined co-delivery of cDNAs for B7-1 and human carcinoembryonic antigen (CEA) within separate plasmids or a dual plasmid with two independent expression cassettes. Intramuscular delivery of the dual expression plasmid produced anti-CEA antibody responses and antitumor effects superior to those generated by plasmid DNA encoding CEA alone. However, co-delivery of cDNAs encoding B7-1 and CEA in the form of two separate plasmids produced no augmentation. The importance of single plasmid delivery suggests the effectiveness of this strategy is contingent upon co-expression of B7-1 and CEA within the same cell. The success of cutaneous polynucleotide immunization by particle bombardment is thought to derive largely from the presence of Langerhans cells within the skin. We hypothesized that co-delivery of plasmid DNA encoding granulocyte-macrophage colony stimulating factor (GM-CSF) by particle bombardment would enhance the antigen presenting capacity of Langerhans cells at the inoculation site similar to its effects in vitro. Augmentation of CEA-specific lymphoblastic transformation and antibody response was observed when plasmid GM-CSF (pGM-CSF) was administered 3 days prior to each dose of plasmid DNA encoding CEA. These strategies for augmentation of immune response to polynucleotide immunization should be applicable to a wide variety of antigenic targets including infectious agents and other tumor-associated antigens.

Animals↗

Phase II study of dual 131I-labeled monoclonal antibody therapy with interferon in patients with metastatic colorectal cancer.

The combination of COL-1 (anti-CEA) and CC49 (anti-TAG-72) has shown an increase in binding and distribution in colon cancer by immunoperoxidase staining compared to either antibody alone. To overcome tumor heterogeneity and allow delivery of higher radiation dose, 131I-labeled COL-1 and CC49 at a total dose of 75 mCi/m2 (2775 MBq/m2) were simultaneously administered to 14 patients with metastatic colon cancer. alpha-IFN (3 x 10(6) IU) was given s.c. on days -5 to +3 to increase carcinoembryonic antigen and TAG-72 antigen expression. Most patients had mild symptoms during IFN therapy, including mild neutropenia, fever, and malaise, which rapidly subsided after IFN cessation. No acute allergic reactions occurred with radioimmunotherapy; two patients experienced transient, delayed grade 2 arthralgias. Transient neutropenia and/or thrombocytopenia, which was maximal at 4-6 weeks, were consistent side effects without adverse events. All patients had tumor localization, and 13 of 14 patients achieved 4+ (highest grade) localization readings to at least one known site of disease. No objective responses occurred; 4 patients were stable and 10 progressed. Tumor dose estimates varied from 393 to 1327 cGy, including liver and extrahepatic sites. Combining two complementary antibodies and IFN administration appeared to increase localization intensity and radiation doses at tumor sites as compared to historical controls. The amount of radiation delivered to tumor sites was still below that required to cause tumor regressions in metastatic colorectal cancer.

Adult↗

Phase II trial of murine monoclonal antibody D612 combined with recombinant human monocyte colony-stimulating factor (rhM-CSF) in patients with metastatic gastrointestinal cancer.

In a Phase II study, 14 patients with metastatic gastrointestinal cancer received the mAb D612 (40 mg/m2, days 4, 7, and 11) in combination with recombinant human monocyte colony-stimulating factor [(rhM-CSF) 80 micrograms/kg/days 1-14]. The combined treatment was well tolerated and resulted in characteristic biological activity associated with each of the agents. Thus, 10 of 14 patients experienced D612-associated secretory diarrhea, which responded to the prostaglandin inhibitor Indomethacin in 5 of 7 patients. rhM-CSF therapy was associated with peripheral monocytosis (peak absolute monocyte count, 1444 +/- 394/mm3) and thrombocytopenia (nadir count, 78 +/- 10/mm3). Monocyte surface marker analysis revealed a high baseline expression of CD16+ cells in our patient population with an additional increase with rhM-CSF therapy. We observed a correlation between the degree of thrombocytopenia and the pretreatment CD16+ monocyte count. Of the plasma cytokines assayed, serum Neopterin demonstrated the most consistent increase during rhM-CSF therapy. There was a significant difference in the half-life of the first and last dose of D612 (35.8 +/- 2 versus 27 +/- 2.9 h; P < 0.05). Eleven of fourteen patients developed low-moderate levels of anti-D612 antibody. Despite the observed biological activity of both rhM-CSF and D612 and the previously described in vitro synergy, no clinical antitumor responses were observed in this Phase II study.

Adult↗

Phase I clinical and pharmacological study of suppression of human antimouse antibody response to monoclonal antibody L6 by deoxyspergualin.

Development of human antimouse antibody (HAMA) is a major limiting factor in the application of murine mAb for clinical use. A novel immunomodulatory drug, deoxyspergualin (DSG), has shown potential to suppress antimouse antibody response in preclinical model systems. We conducted a Phase I trial to determine the effect of DSG on HAMA response to murine mAb L6 administered to patients with advanced cancers (in previous trials, this antibody elicited HAMA in two-thirds of the treated patients). L6 mAb was administered at a fixed dose of 200 mg/m2 on days 1-5. DSG was administered at doses of 50 mg/m2 [dose level (dl) 1] or 150 mg/m2 (dls II and III) on days 1-7. Treatment courses were repeated every 6 weeks (dls I and II) or every 3 weeks (dl III). HAMAs were quantitated by a commercially available ELISA assay (ImmuSTRIP; anti-isotypic antibodies) and a radiometric assay (antiisotypic and anti-idiotypic antibodies). Pharmacokinetics of L6 and DSG was also studied in all consenting patients. Among 24 evaluable patients, 2 patients developed detectable HAMAs using the ELISA (one each at dls I and II) after a median follow-up of 122 days (P = 0.0001 as compared to historical controls). Even in the two patients who developed HAMA, the HAMA levels were quite low (160 and 181 ng/ml; historical experience, 70-38,744 ng/ml). The radiometric assay detected anti-L6 antibodies in 13 patients (4, 6, and 3 at dls I-III, respectively) after a median of 82 days. The median highest anti-L6 antibody level was 129 ng/ml (range, 21-2150). The highest anti-L6 antibody level at dl III was only 44 ng/ml. The results suggest suppression of anti-idiotypic response also. No clinical antitumor activity was observed, and no significant changes in T4/T8 subsets or immunoglobulins occurred (suggesting a lack of generalized immunosuppression). We conclude that DSG can suppress HAMA response to L6. A starting dose of 150 mg/m2/day is recommended for Phase II trials to confirm this observation.

Adult↗

CD16+ monocytes in patients with cancer: spontaneous elevation and pharmacologic induction by recombinant human macrophage colony-stimulating factor.

The small subset of circulating monocytes that express the maturation-associated CD16 antigen has recently been reported to be elevated in patients with bacterial sepsis. We now show that this novel CD16+ monocyte population is also spontaneously expanded in patients with cancer. We studied 14 patients with metastatic gastrointestinal carcinoma enrolled ina clinical trial of recombinant human macrophage colony-stimulating factor (rhMCSF) plus monoclonal antibody D612. We found that before any cytokine treatment, 12 of 14 patients constitutively displayed significant elevations in both the percentage and the absolute number of CD16+ monocytes, as compared with both normal subjects and ill patients with elevated monocyte counts but without malignancy. CD16+ monocytes accounted for 46% +/- 22% of total monocytes in the patients with cancer versus 5% +/- 3% for controls (P < .01). The increase was not attributable to infection or intercurrent illness and appeared to be associated with the underlying malignancy itself. A similar spontaneous elevation of CD16+ monocytes was observed in 35 of 44 additional patients diagnosed with a variety of other solid tumors. When patients with gastrointestinal carcinoma were treated with rhMCSF, there was a marked further increase in the percentage of CD16+ monocytes (to 83% +/- 11%), as well as in the absolute number of CD16+ cells and the level of CD16 antigen expression. In every case, the patients with cancer showed a greater CD16+ monocyte response than the maximal response obtained in normal volunteer subjects treated witha similar regimen of rhMCSF (n = 5, P < .001), suggesting that the presence of malignancy primed patients for enhanced responsiveness to rhMCSF. We hypothesize that spontaneous expansion of the CD16+ monocyte population may represent a novel biologic marker for a widespread and previously unsuspected host immune response to malignancy.

Adult↗

A Sindbis virus mRNA polynucleotide vector achieves prolonged and high level heterologous gene expression in vivo.

The direct intramuscular delivery of naked plasmid DNA has been demonstrated to allow expression of encoded heterologous genes in the target myocytes. The method has been employed to elicit immunization based upon delivery of antigen encoding plasmid DNA. For application in the context of achieving anti-tumor immunization against antigenic transforming oncoproteins, delivery of plasmid DNAs encoding these molecules would create significant potential safety hazards. As an alternative to DNA polynucleotide vectors, we explored the utility of mRNA vehicles for inducing foreign gene expression in muscle cells in vivo. Synthetic reporter-gene encoding mRNA transcripts were derived for this analysis. The Sindbis virus vector was also used to derive luciferase mRNA transcripts which possessed self-replication capacity. In these studies, it could be shown that the replicative vector was capable of directing significantly elevated levels of reporter gene expression in myocytes compared to a non-replicative mRNA species. In addition, the replicative species was capable of achieving significantly prolonged levels of in vivo gene expression compared to non-replicative mRNA. Both of these characteristics will make replicative mRNA vectors of utility for polynucleotide-based immunization protocols.

Animals↗

Characterization of a messenger RNA polynucleotide vaccine vector.

We have constructed mRNA transcripts encoding luciferase and human carcinoembryonic antigen (CEA) which are capped, polyadenylated, and stabilized by human beta-globin 5' and 3' untranslated regions. The mRNA construct encoding human CEA directed CEA expression in mouse fibroblasts in vitro following liposome-mediated transfection. The luciferase encoding mRNA transcripts mediated luciferase expression in vivo following i.m. injection. Based on the demonstration of protein expression in vitro and in vivo, the feasibility of using such a vector as a tumor vaccine was examined. In this pilot study, seven mice received 50 micrograms mRNA transcripts encoding CEA twice weekly for 5 weeks by i.m. injection followed by challenge with syngeneic, CEA-expressing tumor cells. This dose and schedule "primed" an immune response to CEA. Five of seven mRNA-immunized mice demonstrated anti-CEA antibody 3 weeks after tumor challenge whereas control mice had no evidence of antibody response. This strategy might be particularly useful to induce an immune response to a proto-oncogene product or growth factor which poses a risk of inducing malignant transformation consequent to prolonged protein expression.

Animals↗

A carcinoembryonic antigen polynucleotide vaccine for human clinical use.

We have constructed a plasmid DNA encoding the full-length complementary DNA for human carcinoembryonic antigen (CEA) under transcriptional regulatory control of the cytomegalovirus early promoter/enhancer (pCEA) and demonstrated that this plasmid can function as a polynucleotide vaccine to elicit a CEA-specific immune response. This immune response protects against tumor challenge with syngeneic CEA-transduced colon carcinoma cells in mice. In the present work, the pCEA construct and purification method were modified to eliminate nonessential viral sequences, the ampicillin selectable marker, mutagens, and endotoxin to produce a reagent suitable for human clinical trials. The human use plasmid (pGT37) directs CEA expression at levels comparable with the original pCEA plasmid and can be propagated to yield large quantities of plasmid DNA based on kanamycin selection. A simple extraction technique greatly reduces contamination by endotoxin. Six weekly intramuscular injections of pGT37 elicited CEA-specific lymphoblastic transformation and antibody response in five of five mice and fully protected 10 of 10 mice against tumor challenge with syngeneic CEA-expressing colon cancer cells 42 days from the first plasmid injection. Thus, pGT37 encoding a tumor-associated antigen (CEA) has been shown to elicit cellular and humoral immune responses and mediate antitumor effects in vivo. This plasmid is suitable for human use and can be easily propagated in the laboratory.

Adenocarcinoma↗

A carcinoembryonic antigen polynucleotide vaccine has in vivo antitumor activity.

We have constructed a plasmid DNA encoding the full-length cDNA for human carcinoembryonic antigen (CEA) driven by the cytomegalovirus early promoter/enhancer and demonstrated that this plasmid can function as a polynucleotide vaccine. The immune response elicited by the CEA polynucleotide vaccine is dose and schedule dependent. There appears to be a threshold dose of 50 micrograms capable of inducing CEA-specific lymphoblastic transformation, lymphokine release, and antibody response. Doses of 10 micrograms were significantly less effective. When 50-micrograms doses are employed, thrice weekly or weekly vaccination schedules more reliably elicit CEA-specific immune responses by day 43 than does an every-3-weeks schedule. Furthermore the CEA polynucleotide vaccine can immunoprotect against challenge with syngeneic CEA-transduced colon carcinoma cells as early as 3 weeks after the first vaccination. Studies are ongoing to demonstrate the ability of CEA polynucleotide vaccination to treat pre-existing syngeneic mouse colon and breast carcinomas expressing human CEA.

Animals↗

Initial clinical evaluation of iodine-125-labeled chimeric 17-1A for metastatic colon cancer.

UNLABELLED: The internalizing properties of murine antibody 17-1A in human colon cancer cells make it attractive as a carrier for radionuclides with short range emissions such as 125I. Murine 17-1A IgG2a antibody, which reacts against human gastrointestinal cancers, has been chimerized by joining its variable region with human IgG1 k constant region. A pilot clinical trial of increasing doses of 125I-chimeric 17-1A in patients with metastatic colorectal cancer has been conducted. METHODS: Patients were treated in groups of 2-4; 2 patients at Hahnemann University and 26 at the University of Alabama at Birmingham. Groups 1-5 received single administrations with 125I doses of 20, 40, 60, 80 or 100 mCi. Subsequent groups received therapeutic doses of 150, 200 or 250 mCi, with the dose subdivided into infusing of 50 or 100 mCi at 4-day intervals. All treatments were delivered in an outpatient setting using radiation precautions. Labeling at 10 mCi/mg antibody was performed on the day of treatment. RESULTS: Pharmocokinetics of circulating antibody was studied for initial patients, showing alpha T 1/2 of 17-27 hr and beta T 1/2 of 100-190 hr. Whole-body T 1/2 of radioactivity was determined by measuring urinary excretion or gamma emissions. Treatment was well tolerated without significant acute or late side effects. No significant bone marrow suppression or other dose-limiting toxicities were noted over this dose range. No objective responses were noted. CONCLUSION: These results show that high-dose outpatient radioimmunotherapy with an 125I-labeled internalizing antibody can be achieved without significant patient toxicity or radiation hazard.

Ambulatory Care↗

Phase I trial of an anti-CD19 deglycosylated ricin A chain immunotoxin in non-Hodgkin's lymphoma: effect of an intensive schedule of administration.

In a phase I trial, eight patients with non-Hodgkin's B-cell lymphoma received mouse IgG1k monoclonal antibody HD37 specific for CD19 conjugated to deglycosylated ricin A chain (dgA) administered in four doses at 4-h intervals with total doses ranging from 4-12 mg/m2. This schedule generated serum levels of immunotoxin which were sustained over 36 h. The plasma half-life of HD37-dgA was 17 +/- 4 (SD) h. The HD37-dgA conjugate was stable in vivo as demonstrated by serum levels of HD37-dgA conjugate comparable to those of total HD37 antibody. Peak serum levels attained after the fourth dose ranged from 0.36 to 5.63 micrograms/ml. Two of seven evaluable patients developed modest human anti-immunotoxin antibody responses. Toxicity in patients 1-7 consisted of dose-dependent capillary leak syndrome with hypoalbuminemia, orthostatic hypotension, and weight gain. Patient 8 died on day 8 with severe capillary leak, bronchopneumonia, and rhabdomyolysis. All patients had progressive disease at 4 weeks except patient 8, who exhibited a near-complete remission before his death. This intensive schedule appears to produce inordinate toxicity with a maximal tolerated total dose of 8 mg/m2.

Adult↗

Characterization of poliovirus replicons encoding carcinoembryonic antigen.

Recombinant vaccines hold great promise for the prevention and therapy of infections diseases and cancer. We have explored the use of poliovirus as a recombinant vector to deliver genes into cells for the purpose of vaccination. For our studies, we have chosen to express the gene-encoding carcinoembryonic antigen (CEA) using a novel poliovirus vector. We have constructed a recombinant CEA-poliovirus replicon in which the CEA gene was substituted for the poliovirus capsid gene. Following in vitro transcription, the RNA was transfected into cells to demonstrate CEA expression. We found that a genome in which the region encoding the signal sequence of the CEA protein (amino acids 1-34) was removed was replication competent (i.e., referred to as a replicon). We encapsidated the CEA-poliovirus replicon by transfecting this RNA into cells previously infected with a recombinant vaccinia virus (VV-P1) which expresses the poliovirus capsid protein (P1). Serial passage in the presence of VV-P1 resulted in the generation of stocks of these encapsidated replicons. Infection of cells with the encapsidated replicon containing the CEA-poliovirus genome resulted in expression of the CEA protein. To test immunogenicity, mice susceptible to poliovirus were given three doses of the encapsidated replicons via the i.m. route. By the third administration, a CEA-specific antibody response was detected. Potential future use of the poliovirus replicon system as both a parenteral and oral vaccine vector is discussed.

Amino Acid Sequence↗

Immune response to a carcinoembryonic antigen polynucleotide vaccine.

We have constructed a DNA plasmid encoding the full length complementary DNA for human carcinoembryonic antigen (CEA) driven by the cytomegalovirus early promoter/enhancer (plasmid DNA encoding human CEA) and demonstrated that this plasmid can function as a polynucleotide vaccine. This polynucleotide vaccine induced humoral and/or cellular immune responses specific for human CEA in all 5 immunized mice. Lymphoblastic transformation data with the use of enriched T-cell populations detected the presence of CEA-specific memory T-cells in 3 of 5 mice. Lymphocytes from 2 of 5 mice had interleukin 2/interleukin 4 release in response to CEA. CEA specificity was confirmed by the absence of reactivity to a control antigen and lack of CEA reactivity among mice vaccinated with a control plasmid encoding chloramphenicol acetyltransferase. Four of 5 mice vaccinated with plasmid DNA encoding human CEA demonstrated anti-CEA antibody responses. This immune response compared favorably with a positive control group of mice immunized with vaccinia-CEA by a dose and schedule previously shown to induce immunoprotection and therapy against a human CEA expressing syngeneic murine colon carcinoma model. Studies are ongoing to establish the construct, dose, and schedule to elicit optimal CEA-specific immune response as well as immunoprotection and therapy against human CEA expressing syngeneic murine adenocarcinoma models.

Animals↗