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Biomedical subjects

A F LoBuglio

Publications and source records attributed to A F LoBuglio.

At least 73 records · Page 4Linked to original sources
PubMed1991

Pharmacokinetics, immune response, and biodistribution of iodine-131-labeled chimeric mouse/human IgG1,k 17-1A monoclonal antibody.

Pharmacokinetics, immunogenicity, and biodistribution of a 131I-labeled mouse/human chimeric monoclonal antibody (C-17-1A) was studied in six metastatic colon cancer patients. Pharmacokinetics obtained from serum radioactivity or chimera concentration were identical after 5 mCi of 131I-C-17-1A with mean alpha half-lives of 17.6 +/- 2.3 and 19.7 +/- 2.9 and mean beta half-lives of 100.9 +/- 16.1 and 106.4 +/- 14.1 hr, respectively. HPLC analysis documented the monomeric chimeric 17-1A without evidence of immune complexes or free 131I. None of the patients developed antibody after 131I-chimeric 17-1A exposure. Radiolocalization occurred in known areas of disease greater than 4 cm in all patients. The half-life of total-body radioactivity was 58 +/- 7 hr by whole-body counts and 64 +/- 13 hr by urine measurements. Whole-body and bone marrow dose estimates ranged from 0.75-1.03 and 0.76-1.05 rad/mCi, respectively. These studies confirm the prolonged circulation and reduced immunogenicity of chimeric 17-1A versus murine 17-1A. Marrow radiation exposure using antibodies with prolonged circulation is a critical factor in planning for radioimmunotherapeutic applications.

Adenocarcinoma↗
PubMed1990

A phase II trial of murine monoclonal antibody 17-1A and interferon-gamma: clinical and immunological data.

A group of 15 patients with metastatic colorectal adenocarcinoma received a combination of interferon gamma (0.1 mg/m2, days 1-15) and the murine monoclonal antibody 17-1A (400 mg, days 5, 7, 9 and 12). The treatment was tolerated with minimal toxicity. Of the 14 evaluable patients, 13 developed human antibody to murine 17-1A, with 11 patients demonstrating antibody to the variable region of 17-1A (anti-idiotype). Antibody to the variable region was inhibited by 17-1A but not by mouse immunoglobulin. Sera from patients with substantial anti-idiotype reactivity were capable of inhibiting the binding of murine 17-1A to antigen expressing LS174-T cells thus indicating the presence of antibody directed against the 17-1A combining site (mirror-image anti-idiotype). The median survival of the whole group was 56 weeks and there was no correlation between clinical response/survival and the development of anti-idiotype antibody.

Adenocarcinoma↗
PubMed1990

Pharmacokinetics of a mouse/human chimeric monoclonal antibody (C-17-1A) in metastatic adenocarcinoma patients.

The pharmacokinetic characteristics of a mouse/human chimeric monoclonal antibody (C-17-1A) were determined in 10 patients with metastatic adenocarcinoma following the administration of either 10-mg or 40-mg infusions as a single or multiple dose. The administration of single 10-mg (n = 5) and 40-mg (n = 5) doses infused over 1 hr resulted in mean apparent steady-state distribution volumes of 4.13 +/- 0.97 and 5.16 +/- 1.92 liters, respectively, indicating that C-17-1A appears to distribute throughout the vascular compartment and into limited extracellular fluid volume. The disposition of C-17-1A was adequately characterized using a two-compartment open model with mean distribution half-lives of 15.8 and 18.5 hr and mean elimination half-lives of 90.0 and 97.6 hr for the 10- and 40-mg groups, respectively. A linear relationship was observed between AUC and dose (micrograms/kg). The clearance of C-17-1A was correlated linearly with total Ig, IgG, and tumor size. Multiple administration of either 10-mg (n = 3) or 40-mg (n = 3) doses of C-17-1A infused over 1 hr every 14 days for a total of three doses resulted in superimposable mean serum concentration versus time data and consistent mean pharmacokinetic characteristics. These data indicate that C-17-1A exhibits linear, nonsaturable distribution and elimination characteristics in man over the dose range studied (i.e., 130 to 880 micrograms/kg). The multiple-dose pharmacokinetics of C-17-1A were predictable, indicating a lack of an antibody response to C-17-1A over a period of 42 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1990

Initial evaluation of human monoclonal anti-lipid A antibody (HA-1A) in patients with sepsis syndrome.

HA-1A, a human monoclonal immunoglobulin M antibody that binds specifically to the lipid A domain of endotoxin, was administered to septic patients to evaluate the safety, pharmacokinetics, and immunogenicity of the antibody. Thirty-four patients received a single infusion of either 25 mg, 100 mg, or 250 mg, and were followed clinically for 14 to 21 days after treatment. HA-1A serum levels were measured before infusion and frequently after infusion with a radiometric assay. A one-compartment pharmacokinetic model was fit to the measured serum levels, and accurately described the changes in HA-1A level over time in each dose group (r2 = .99). The mean +/- SEM apparent volume of distribution of HA-1A was 48.5 +/- 4.5 ml/kg, and the mean serum clearance was 2.8 +/- 0.4 ml/kg.h. The mean serum half-life of HA-1A was 15.9 +/- 1.5 h. The mean serum level one hour after a 100-mg dose was 33.2 +/- 2.4 micrograms/ml, and the mean concentration 24 h later was 9.1 +/- 1.6 micrograms/ml. The dose administered and presence of Gram-negative bacterial infection did not significantly influence the volume of distribution or serum clearance. No adverse reactions to HA-1A were observed, and no antibodies against HA-1A were detected in any patient. These data indicate that the pharmacokinetics of HA-1A are well described by a one-compartment pharmacokinetic model, and that HA-1A is safe and nonimmunogenic in patients with sepsis.

Adult↗
PubMed1990

Chemotherapy of intermediate- and high-grade non-Hodgkin's lymphomas with a high-dose doxorubicin-containing regimen.

Forty-seven previously untreated patients with intermediate- or high-grade non-Hodgkin's lymphoma were treated with four courses of a regimen that consisted of high-dose (120 mg/m2) Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), vincristine (2 mg), cytarabine (3 gm/m2), and dexamethasone (50 mg intravenously [IV] on day 1 and 20 mg/day orally on days 2 to 5) (AVAD), which was administered every 3 to 4 weeks. The median age of the patients was 58 years; 72% were Ann Arbor stage IV, 49% had "B" symptoms, 62% had masses larger than 7 cm, 40% had masses at least 10 cm in diameter, and 49% had serum lactate dehydrogenase (LDH) greater than 250 U/L. Overall, 72% of the patients (89% of diffuse large-cell lymphoma [DLCL] patients) attained complete (CR) or probable complete responses (PCR), and relapses occurred in 32%. There were no episodes of clinical congestive heart failure, but one patient developed recurrent ventricular arrhythmias. Fever during neutropenia occurred with 65% of treatment courses. Three deaths were attributed primarily to complications of therapy. The lymphoma-free survival of all entered patients is 51% (24 of 47), with a follow-up of 30 to 67 months (median, 58 months). These results confirm that high CR/PCR and long-term survival rates can be achieved in patients with aggressive histologies of non-Hodgkin's lymphomas, even in groups with poor prognostic factors, using high-dose anthracycline-containing chemotherapy regimens delivered over a short period of time. However, the apparently higher relapse rate in comparison to our previous study leads us to speculate that consolidation with noncross-resistant agents may be helpful in increasing even further the cure rate in this group of patients.

Adult↗
PubMed1990

Limited sampling models for HA-1A IgM monoclonal antibody.

In this study, limited sampling models for HA-1A human IgM monoclonal antibody were developed to predict the area under the concentration time curve from timed serum concentrations. Patients were administered 15 minute infusions of 25 mg (11 patients), 100 mg (15 patients), and 250 mg (2 patients). A detailed pharmacokinetic analysis (eight time points) was performed to obtain the area under the curve for each of the 28 patients using a one-compartment model with the values normalized to a dose of 100 mg. Various models were then developed to estimate the area under the curve from one and two timed concentrations using regression analysis methodology. Of these models, four were determined to be of interest with coefficients of determinations ranging from 0.92 to 0.97. They performed quite well in predicting the area under the curve values with relative root mean squared predictive error of 7.1 to 10.8% and relative mean predictive error of -4.5 to + 6.9%. These models should be extremely useful in larger scale, Phase II/III studies of HA-1A in correlating the estimated area under the curve with various demographic data, toxicity, and efficacy.

Antibodies, Monoclonal↗
PubMed1989

Quantitative assay of a human monoclonal IgM antibody (HA-1A) in human serum.

A rapid, specific and sensitive radiometric assay was developed capable of quantitating serum levels of HA-1A, a human IgM monoclonal antibody to endotoxin. 'Private' anti-idiotypic murine monoclonal antibodies were produced and utilized in the assay to avoid cross-reactivity with normal human IgG, IgM, IgA, IgE or IgD. The presence of E. coli or gram-negative lipopolysaccharide in the sera did not affect the ability of the assay to detect HA-1A. The sensitivity of the assay was calculated to be 25 ng/ml with an interassay coefficient of variation of less than 10%. In one patient given 100 mg of HA-1A, peak serum concentration was 101.5% of the predicted value with a mean plasma half life of 24.5 h. This assay will be useful in establishing the pharmacokinetics of HA-1A and in monitoring serum levels during phase II and phase III clinical trials.

Animals↗
PubMed1989

Effect of intravenous gammaglobulin on circulating and platelet-bound antibody in immune thrombocytopenia.

Ten patients with idiopathic thrombocytopenic purpura (ITP) were studied before and following a rise in circulating platelets subsequent to infusions of intravenous gammaglobulin (400 mg/kg/day x 5 days). We quantitated the amount of circulating IgG capable of binding to normal donor platelets in vitro using an 125I-monoclonal anti-human IgG assay, as well as the amount of IgG associated with the patients' platelets before and following therapy. We found no evidence for a decrease in platelet-specific IgG antibodies in these patients undergoing an acute response to therapy. These data suggest that the short-term efficacy of intravenous gammaglobulin is due to effects other than a substantive reduction in platelet reactive antibodies, such as the alteration of IgG-coated platelet destruction.

Autoantibodies↗
PubMed1989

Mouse/human chimeric monoclonal antibody in man: kinetics and immune response.

A mouse/human chimeric monoclonal antibody (mAb) composed of the variable regions of murine 17-1A mAb and the constant regions of human IgG-1K immunoglobulin was administered to 10 patients with metastatic colon cancer. Four patients received single infusion of 10 mg (n = 2) or 40 mg (n = 2). Six patients received three infusion of 10 mg (n = 3) or 40 mg (n = 3) at 2-week intervals. The pharmacokinetics were similar at both dose levels and at the second and third infusions. The plasma disappearance curves were best fit by a two-compartment model having a mean alpha T1/2 of 17.5 hr (range 13-23 hr) and a mean beta T1/2 of 100.5 hr (range 65-139 hr). One patient who received three 40-mg doses of chimeric IgG-1K 17-1A mAb (day 0, 14, and 28) was the only patient to exhibit a detectable but modest antibody reactivity to chimera on days 63 and 84. The antibody reactivity was inhibited by murine 17-1A mAb, indicating that the antibody response was directed to the murine variable region of the chimera. The patients had no toxic or allergic reactions. This chimeric form of 17-1A mAb has an approximate 6-fold longer circulation time and appears to be substantially less immunogenic than its murine counterpart. These characteristics may provide an advantage in the clinical application of such chimeric molecules in therapeutic trials in humans.

Adenocarcinoma↗
PubMed1989

Monocyte-platelet interaction in immune and nonimmune thrombocytopenia.

Platelets from 24 patients with immune thrombocytopenia resistant to standard therapy (refractory ITP), 35 patients with nonimmune thrombocytopenia (non-ITP), and 32 normal donors were studied in regard to platelet surface-bound IgG (PBIgG) and the ability of these platelets to be bound by human monocytes in vitro (monocyte-platelet rosette assay). Fourteen (58%) of the platelet samples from refractory ITP patients but none (0%) from the non-ITP or control donors had PBIgG greater than 800 molecules IgG/platelet. Seventeen of 24 (71%) of the ITP patients had platelets which demonstrated increased monocyte-platelet rosette formation [rosette index (RI) greater than 2], whereas only four (11%) of the non-ITP patients had such platelets. There was a direct correlation between PBIgG and rosette index for the platelets from resistant ITP patients. There was no correlation of severity of thrombocytopenia with PBIgG or rosette index. Monocyte-platelet interaction in the presence of elevated PBIgG is mediated through the monocyte Fc-receptor. Platelets from five of ten refractory ITP patients with PBIgG less than 800 molecules IgG/platelet had increased rosette formation. Monocyte-platelet interaction in the absence of increased PBIgG may be due to small amounts of platelet surface IgG which are still able to mediate monocyte Fc-receptor interaction or to alternate membrane receptor interaction through the monocyte C3 receptor. Our data underscore the pathophysiologic relevance of monocyte/macrophage-mediated interaction in immune platelet destruction syndromes.

Autoantibodies↗
PubMed1989

Quinidine-induced immune thrombocytopenia.

We have identified six cases of quinidine-induced immune thrombocytopenia based on clinical evidence and in association with elevated amounts of platelet surface IgG. The degree of thrombocytopenia did not correlate with severity of clinical symptoms, nor did it predict the amount of IgG on the platelet surface. Three of the patients recovered promptly after drug discontinuation alone whereas the other patients received additional corticosteroid therapy. The clinical presentation, mode of diagnosis, and therapeutic considerations in the treatment of drug-induced thrombocytopenia are discussed.

Aged↗
PubMed1988

Mouse/human chimeric antibodies to a tumor-associated antigen: biologic activity of the four human IgG subclasses.

Variable region genes from mouse monoclonal antibody 17-1A (gamma 2a kappa) with specificity for human gastrointestinal malignancies have been paired with human immunoglobulin constant region genes (for heavy and light chains) to produce mouse/human chimeric immunoglobulin molecules (chIgG) for each of the four human IgG subclasses. Mouse 17-1A and the four chIgG bound similarly to two human colon cancer cell lines and had comparable binding affinities. The chIgG1 and chIgG3 molecules mediated lymphocyte and monocyte antibody-dependent cell-mediated cytotoxicity (ADCC) to colon cancer tumor cell lines comparable to that of the parent murine 17-1A. The chIgG2 and chIgG4 molecules were able to mediate ADCC to colon cancer cell lines but were clearly inferior to the chIgG1 and chIgG3 reagents. None of the chIgG antibodies or the murine 17-1A was able to mediate complement lysis of colon cancer cell lines. These studies demonstrate the ability to produce all four human IgG subclass chimeric molecules which retain biologic activity. We have confirmed the subclass preferences of human lymphocyte and monocyte Fc receptors for human IgG subclasses previously determined by studies with monomeric or aggregated IgG. These data may aid in the selection of chimeric antibodies for in vivo trials.

Animals↗
PubMed1988

Phase I trial of multiple large doses of murine monoclonal antibody CO17-1A. I. Clinical aspects.

Twenty-five patients with metastatic gastrointestinal adenocarcinoma received one to four infusions (400 mg) of murine monoclonal antibody CO17-1A. Eleven patients had mild gastrointestinal symptoms, and one had a transient flushing episode. Two of five who received three weekly infusions had readily reversible anaphylactic reactions at the time of the third infusion (day 15). There were no other toxic effects. One patient had a complete remission and is surviving at greater than 104 weeks, and four had stable disease. The median survival for the whole group was 57 weeks. In general, the antibody infusions were well tolerated but had modest antitumor effects.

Adenocarcinoma↗
PubMed1988

Phase I trial of multiple large doses of murine monoclonal antibody CO17-1A. II. Pharmacokinetics and immune response.

Twenty-five patients with metastatic gastrointestinal adenocarcinoma received one to four infusions of large doses (400 mg) of murine monoclonal antibody CO17-1A (17-1A). The pharmacokinetics of 17-1A at the time of first, second, third, or fourth infusion were not statistically different; plasma half-lives were 15.0 +/- 1.7 hours (n = 5), 15.1 +/- 1.8 (n = 10), 25.3 +/- 6.2 (n = 3), and 14.4 +/- 1.8 (n = 5), respectively. Most patients had an antibody response to 17-1A, with peak levels occurring 15-22 days after infusion. The presence of serum antibody to 17-1A at the time of the second or third infusion did not significantly alter the pharmacokinetics of this large dose of antibody. Four of 25 patients failed to develop an antibody response, but this did not correlate with the amount of 17-1A administered. The administration of four doses of 400 mg over 1 week provided continuously circulating 17-1A for 10 days.

Animals↗
PubMed1988

Clinical use of a standard kit-preparation of radiolabeled monoclonal antibody 96.5 in the diagnostic imaging of metastatic melanoma.

We studied the efficiency of a standard-kit preparation using 1 mg 111In-labeled 96.5 monoclonal antibody in combination with 19 mg of unlabeled antibody in the diagnostic imaging of 27 patients with documented metastatic melanoma. Twenty-three of 26 patients (88%) demonstrated immunoscintigraphic localization of tumor. Of 104 metastatic sites previously documented by conventional studies, 62 (60%) were identified by immunoscintigraphy. A total of 77 sites demonstrated localization of radiolabeled antibody. Fifty-four (70%) corresponded to known sites of disease; eight sites (10%) were "discovered" by immunoscintigraphy and subsequently confirmed by conventional studies; 15 imaged sites (20%) could not be confirmed by conventional studies. Size and location of metastasis appear to be important features that influence imaging efficiency. Tumor size (greater than or equal to 2 cm v less than 2 cm) appears to be the statistical dominant determinant. The feasibility and potential clinical use of radioimmune imaging of tumors is discussed.

Adult↗
PubMed1988

Human lymphocyte and monocyte lysis of tumor cells mediated by a mouse/human IgG1 chimeric monoclonal antibody.

The mouse monoclonal antibody 17-1A (gamma 2a, kappa) recognizes a tumor-associated antigen expressed on human gastrointestinal malignancies and has been used in Phase I and II clinical trials. Chimeric genetic constructs have been produced using 17-1A variable region genes (VL and VH) and the constant region genes for human kappa light chains and gamma 1 heavy chains (C kappa and gamma 1). The chimeric gene constructs were transfected into mouse myeloma cells for antibody production. The secreted mouse/human chimeric antibody contains the antigen-binding domain of 17-1A and the human (gamma 1, kappa) constant regions. Native mouse 17-1A and the chimeric antibody (chIgG1) were analyzed for binding to two human colon cancer cell lines and for the mediation of cancer cell line antibody-dependent cellular cytotoxicity by normal human peripheral blood lymphocytes and monocytes in 4 h 51Cr-release assays. The 17-1A and chIgG1 gave similar results in these in vitro biologic assays. This study demonstrates the feasibility of using mouse/human chimeric antibodies in human therapeutic applications.

Animals↗
PubMed1987

Characterization of a mouse/human chimeric monoclonal antibody (17-1A) to a colon cancer tumor-associated antigen.

Mouse monoclonal antibody 17-1A is specific for an antigen expressed on cells of human gastrointestinal malignancies and has been used in radioimmune imaging and therapy trials for patients with colon and pancreatic cancer. The cell line SG3/5 was generated by transfection of a nonproducing mouse myeloma line (SP2/0) with a chimeric gene construct composed of variable regions from the mouse 17-1A immunoglobulin (gamma 2a, kappa) and constant regions of human k and gamma 3 immunoglobulin genes. The secreted immunoglobulin was bound by mouse monoclonal antibodies to human IgG(Fc) and IgG3 but not by staphylococcal protein A. Gel filtration HPLC profiles of purified chimeric antibody were similar to normal human IgG3 but quite different from native 17-1A and normal human IgG1, 2, and 4. Native and chimeric 17-1A had similar patterns of reactivity with colon cancer, other adenocarcinoma, and leukemic cell lines. Competitive inhibition documented that native and chimeric 17-1A had identical capacities to inhibit radiolabeled native 17-1A binding to colon cancer cell lines. Thus, the chimeric 17-1A exhibits molecular characteristics of normal human IgG3 but retains the specificity and binding affinity of the native 17-1A murine monoclonal antibody. The native and chimeric 17-1A mediated similar modest degrees of human lymphocyte and monocyte ADCC in a 4-hr 51Cr release assay, and both failed to mediate complement lysis of colon carcinoma cell lines in the presence of human complement. This human/mouse chimeric monoclonal antibody may be a good candidate for use in clinical trials because it retains the tumor antigen specificity and human effector cell recognition of the native 17-1A, would presumably have a fivefold to 10-fold longer circulating half-life in man, and should be considerably less immunogenic as compared with native murine immunoglobulins.

Animals↗