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A Raubitschek

Publications and source records attributed to A Raubitschek.

At least 19 recordsLinked to original sources
PubMed2003

Engineered CD20-specific primary human cytotoxic T lymphocytes for targeting B-cell malignancy.

BACKGROUND: Immunotherapy for B-cell lymphomas has evolved significantly with the advent of CD20-targeted Ab-based therapeutics. Strategies to invoke or augment cellular anti-lymphoma immune responses may also have considerable therapeutic potential and serve to further augment the clinical efficacy of MAbs. METHODS: We report here the aquisition by priming human cytotoxic T lymphocyte (CTL) effectors of re-directed CD20 specificity by their genetic modification to express a chimeric immunoreceptor consisting of an anti-CD20 single chain Ab extracellular domain molecularly fused to the T-cell receptor complex CD3-zeta cytoplasmic tail (scFvFczeta). Peripheral blood-derived human T-cells were transduced with naked DNA plasmid vector by electoporation then selected for G418 resistance. RESULTS: Following cloning in limiting dilution and ex vivo expansion to large numbers scFvFczeta+ TCRalpha/beta+ CD4- CD8+ CTL display re-directed HLA-unresricted CD20-specific lymphoma cell cytolysis proportional to the cell-surface density of the chimeric immunoreceptor. Engineered CTL clones are also activated through the chimeric immunoreceptor to produce Tc1 cytokines (IFN-gamma) upon co-culture with CD20+ lymphoma stimulator cells. Additionally, CD20-specific CTL proliferate in the presence of lymphoma stimulators and IL-2 (5 U/mL). DISCUSSION: These studies provide the rationale for exploring the clinical utility of adoptive therapy with CD20-specific CTL as a component of immunotherapeutic targeting of CD20+ malignancy.

Antigens, CD20↗
PubMed2000

Human T lymphocyte genetic modification with naked DNA.

Endowing T lymphocytes with novel functional attributes by genetic modification is under development for a broad range of clinical cellular immunotherapy applications. To circumvent many of the limitations associated with viral vector systems, a plasmid-based electroporation system that reliably generates G418-resistant primary human T lymphocyte clones was developed. TCR alpha/beta+ CD4+CD8-, and CD4-CD8+ T lymphocyte clones can be routinely isolated from OKT3-stimulated peripheral blood mononuclear cells electroporated with linear plasmid DNA in a limiting dilution drug selection format. Fluorescence in situ hybridization (FISH) studies performed on T cell metaphase spreads using a probe specific for plasmid sequence demonstrated a single FISH signal doublet that varied in chromosomal location from clone to clone. Southern blot analysis using a Neo-specific probe verified chromosomal integration of plasmid vector at a single site. Band intensity quantitation of blots developed with a zeta-specific probe capable of annealing to both endogenous TCR-zeta and the introduced chimeric zeta sequence demonstrated that integrated plasmid was present at a single copy number. Expression levels of the CD20-specific chimeric immunoreceptor construct from a CMV immediate/early promoter present in the plasmid vector varied widely from clone to clone but remained stable during ex vivo expansion to cell numbers in excess of 10(10). This T lymphocyte genetic modification strategy is currently being piloted in a FDA-sanctioned adoptive therapy trial for recurrent lymphoma.

CD4-Positive T-Lymphocytes↗
PubMed2000

Phase I/II 90Y-Zevalin (yttrium-90 ibritumomab tiuxetan, IDEC-Y2B8) radioimmunotherapy dosimetry results in relapsed or refractory non-Hodgkin's lymphoma.

Dosimetry studies in patients with non-Hodgkin's lymphoma were performed to estimate the radiation absorbed dose to normal organs and bone marrow from 90Y-Zevalin (yttrium-90 ibritumomab tiuxetan, IDEC-Y2B8) treatment in this phase I/II, multicenter trial. The trial was designed to determine the dose of Rituximab (chimeric anti-CD20, Rituxan, IDEC-C2B8, MabThera), the unlabeled antibody given prior to the radioconjugate to clear peripheral blood B cells and optimize distribution, and to determine the maximum tolerated dose of 90Y-Zevalin [7.4, 11, or 15 MBq/kg (0.2, 0.3, or 0.4 mCi/kg)]. Patients received (111)In-Zevalin (indium-111 ibritumomab tiuxetan, IDEC-In2B8 ) on day 0 followed by a therapeutic dose of 90Y-Zevalin on day 7. Both doses were preceded by an infusion of the chimeric, unlabeled antibody Rituximab. Following administration of (111)In-Zevalin, serial anterior/posterior whole-body scans were acquired. Major-organ radioactivity versus time estimates were calculated using regions of interest. Residence times were computed and entered into the MIRDOSE3 computer software program to calculate estimated radiation absorbed dose to each organ. Initial analyses of estimated radiation absorbed dose were completed at the clinical site. An additional, centralized dosimetry analysis was performed subsequently to provide a consistent analysis of data collected from the seven clinical sites. In all patients with dosimetry data (n=56), normal organ and red marrow radiation absorbed doses were estimated to be well under the protocol-defined upper limit of 20 Gy and 3 Gy, respectively. Median estimated radiation absorbed dose was 3.4 Gy to liver (range 1.2-7.8 Gy), 2.6 Gy to lungs (range 0.72-4.4 Gy), and 0.38 Gy to kidneys (range 0.07-0.61 Gy). Median estimated tumor radiation absorbed dose was 17 Gy (range 5.8-67 Gy). No correlation was noted between hematologic toxicity and the following variables: red marrow radiation absorbed dose, blood T(1/2), blood AUC, plasma T(1/2), and plasma AUC. It is concluded that 90Y-Zevalin administered at nonmyeloablative maximum tolerated doses results in acceptable radiation absorbed doses to normal organs. The only toxicity of note is hematologic and is not correlated to red marrow radiation absorbed dose estimates or T(1/2), reflecting that hematologic toxicity is dependent on bone marrow reserve in this heavily pretreated population.

Antibodies, Monoclonal↗
PubMed1999

Phase I/II trial of IDEC-Y2B8 radioimmunotherapy for treatment of relapsed or refractory CD20(+) B-cell non-Hodgkin's lymphoma.

PURPOSE: Yttrium-90 ibritumomab tiuxetan (IDEC-Y2B8) is a murine immunoglobulin G1 kappa monoclonal antibody that covalently binds MX-DTPA (tiuxetan), which chelates the radioisotope yttrium-90. The antibody targets CD20, a B-lymphocyte antigen. A multicenter phase I/II trial was conducted to compare two doses of unlabeled rituximab given before radiolabeled antibody, to determine the maximum-tolerated single dose of IDEC-Y2B8 that could be administered without stem-cell support, and to evaluate safety and efficacy. PATIENTS AND METHODS: Eligible patients had relapsed or refractory (two prior regimens or anthracycline if low-grade disease) CD20(+) B-cell low-grade, intermediate-grade, or mantle-cell non-Hodgkin's lymphoma (NHL). There was no limit on bulky disease, and 59% had at least one mass > or = 5 cm. RESULTS: The maximum-tolerated dose was 0.4 mCi/kg IDEC-Y2B8 (0.3 mCi/kg for patients with baseline platelet counts 100 to 149,000/microL). The overall response rate for the intent-to-treat population (n = 51) was 67% (26% complete response [CR]; 41% partial response [PR]); for low-grade disease (n = 34), 82% (26% CR; 56% PR); for intermediate-grade disease (n = 14), 43%; and for mantle-cell disease (n = 3), 0%. Responses occurred in patients with bulky disease (> or = 7 cm; 41%) and splenomegaly (50%). Kaplan-Meier estimate of time to disease progression in responders and duration of response is 12.9+ months and 11.7+ months, respectively. Adverse events were primarily hematologic and correlated with baseline extent of marrow involvement with NHL and baseline platelet count. One patient (2%) developed an anti-antibody response (human antichimeric antibody/human antimouse antibody). CONCLUSION: These phase I/II data demonstrate that IDEC-Y2B8 radioimmunotherapy is a safe and effective alternative for outpatient therapy of patients with relapsed or refractory NHL. A phase III study is ongoing.

Adolescent↗
PubMed1999

Similarities and differences in 111In- and 90Y-labeled 1B4M-DTPA antiTac monoclonal antibody distribution.

UNLABELLED: Monoclonal antibodies (MoAb) labeled with 90Y are being used for radioimmunotherapy. Because 90Y is a beta emitter, quantitative information from imaging is suboptimal. With the concept of a "matched pair" of isotopes, 111In is used as a surrogate markerfor90Y. We evaluated the differences in biodistribution between 111In- and 90Y-labeled murine antiTac MoAb directed against the IL-2Ralpha receptor. METHODS: The antiTac was conjugated to the 2-(4-isothiocyanatobenzyl)-6-methyl-diethylenetriamine pentaacetic acid (1B4M-DTPA, also known as MX-DTPA). Nine patients with adult T-cell leukemia were treated. Patients received approximately 185 MBq (5 mCi) 111In-labeled antiTac for imaging and 185-555 MBq (5-15 mCi) 90Y-labeled antiTac for therapy. The immunoreactivity of 111In-labeled antiTac was 90%+/-6%, whereas for 90Y-labeled antiTac, it was 74%+/-12%. RESULTS: The differences in blood and plasma kinetics of the two isotopes were small. The area undemeath the blood radioactivity curve was 1.91 percentage+/-0.58 percentage injected dose (%ID) x h/mL for 111In and 1.86%+/-0.64 %ID x h/mL for 90Y. Urinary excretion of 90Y was significantly greater than that of 111In in the first 24 h (P = 0.001), but later, the excretion of 111In was significantly greater (P = 0.001 to P = 0.04). Core biopsies of bone marrow showed a mean of 0.0029+/-0.0012 %ID/g for 111In, whereas the 90Y concentration was 0.0049+/-0.0021 %ID/g. Analyses of activity bound to circulating cells showed concentrations of 500-30,000 molecules of antiTac per cell. When cell-bound activity was corrected for immunoreactive fraction, the ratio of 111In to 90Y in circulating cells was 1.11+/-0.17. Three biopsies of tumor-involved skin showed ratios of 111In to 90Y of 0.7, 0.9 and 1.1. CONCLUSION: This study shows that differences typically ranging from 10% to 15% exist in the biodistribution between 111In- and 90Y-labeled antiTac. Thus, it appears that 111In can be used as a surrogate marker for 90Y when labeling antiTac with the 1 B4M chelate, although underestimates of the bone marrow radiation dose should be anticipated.

Adult↗
PubMed1999

Radioimmunotherapy of relapsed non-Hodgkin's lymphoma with zevalin, a 90Y-labeled anti-CD20 monoclonal antibody.

Approximately 55,400 new cases of non-Hodgkin's lymphoma (NHL) are diagnosed each year, with the overall prevalence of the disease now estimated to be 243,000. Until recently, treatment alternatives for advanced disease included chemotherapy with or without external beam radiation. Based on the results of several clinical trials, the chimeric monoclonal antibody Rituximab has now been approved by the United States Food and Drug Administration as a treatment for patients with relapsed or refractory, low-grade or follicular, B-cell NHL. Several other monoclonal antibodies in conjugated and unconjugated forms have been evaluated in the treatment of NHL. Ibritumomab, the murine counterpart to Rituximab, radiolabeled with 90Y (Zevalin), is presently being evaluated in clinical trials. The success of radioimmunotherapy is dependent upon the appropriate choice of antibody, isotope, and chelator-linker. The Ibritumomab antibody targets the CD20 antigen. The antibody is covalently bound to the chelator-linker tiuxetan (MX-DTPA), which tightly chelates the isotope 90Y. To date, two Phase I/II Zevalin clinical trials have been completed in patients with low-grade, intermediate-grade, and mantle cell NHL. The overall response rate was 64% in the first trial and 67% in the later trial. Phase II and III trials are ongoing.

Antibodies, Monoclonal↗
PubMed1998

CD20 is a molecular target for scFvFc:zeta receptor redirected T cells: implications for cellular immunotherapy of CD20+ malignancy.

The CD20 molecule was evaluated as a B-cell lymphoma target epitope for T cells expressing a CD20-specific single-chain FvFc-zeta (scFvFc:zeta) chimeric receptor. A cDNA construct consisting of a murine kappa leader sequence, CD20-specific scFv, human immunoglobulin (Ig) G1 hinge-C(H)2-C(H)3, the human CD4 transmembrane, and the intracellular signaling domain of the human CD3 complex's zeta chain was synthesized by polymerase chain reaction splice-overlap extension. The human CD4+ Jurkat cell line was electroporated with the CD20-specific scFvFc:zeta construct cloned into the mammalian expression vector pcDNAneo. Western blot analysis of transfectant whole cell lysate with an anti-zeta antibody demonstrated the expression of both endogenous zeta and the chimeric receptor protein, with a mobility consistent with the expected molecular weight of 66 kD under reducing conditions; nonreduced lysate revealed a chimeric receptor complex of approximately 132 kD. The scFvFc:zeta receptor was present on the cell surface as detected by flow cytometry of T-cell transfectants stained with an anti-mouse Fab-specific antibody and anti-human Fc gamma-specific monoclonal antibody. Coculture of Jurkat transfectants with CD20+ lymphoma cells resulted in the accumulation of interleukin (IL)-2 in culture supernatants as detected by ELISA. IL-2 production was triggered by the specific interaction between the CD20 molecule and the scFvFc:zeta as IL-2 was not detected in cultures with mock transfected Jurkat cells or CD20- stimulator cells. Furthermore, IL-2 production was inhibited by the addition of a soluble anti-CD20 monoclonal antibody to cocultured Jurkat transfectants and CD20+ stimulator cells. The capacity of CD20 to trigger the lytic machinery of scFvFc:zeta-expressing cytotoxic T lymphocytes (CTLs) was assessed using the murine allo-specific CD8+ CTL clone 2c. CD20-specific redirected cytolytic activity against human lymphoma targets was observed with 2c transfectants in a 4-hour chromium release assay. These results demonstrate that CD20 can serve as a target epitope for scFvFc:zeta receptor-expressing T cells.

Antibodies, Monoclonal↗
PubMed1996

Minibody: A novel engineered anti-carcinoembryonic antigen antibody fragment (single-chain Fv-CH3) which exhibits rapid, high-level targeting of xenografts.

A novel engineered antibody fragment (VL-VH-CH3, or "minibody") with bivalent binding to carcinoembryonic antigen (CEA) was produced by genetic fusion of a T84.66 (anti-CEA) single-chain antibody (scFv) to the human IgG1 CH3 domain. Two designs for the connecting peptide were evaluated. In the T84.66/212 LD minibody, a two-amino acid linker (generated by fusion of restriction sites) was used to join VH and CH3. In the T84.66/212 Flex minibody, the human IgG1 hinge plus an additional 10 residues were used as the connecting peptide. Size exclusion chromatography of purified minibodies demonstrated that both proteins had assembled into Mr80,000 dimers as expected. Furthermore, analysis by SDS-PAGE under nonreducing conditions was consistent with disulfide bond formation in the hinge of the T84.66 Flex minibody. Purified minibodies retained high affinity for CEA (KA, 2 x 10(9) M(-1)) and demonstrated bivalent binding to antigen. Tumor targeting properties were evaluated in vivo using athymic mice bearing LS174T human colon carcinoma xenografts. 123I-labeled T84.66 minibodies demonstrated rapid, high tumor uptake, reaching 17% injected dose/gram (%ID/g) for the LD minibody and 33%ID/g for the Flex minibody at 6 h following injection. Radioiodinated minibody also cleared rapidly from the circulation, yielding high tumor:blood uptake ratios: 44.5 at 24 h for the LD minibody and 64.9 at 48 h for the Flex minibody. Rapid localization by the T84.66/212 Flex minibody allowed imaging of xenografts at 4 and 19 h after administration.

Animals↗
PubMed1996

Tumor localization of anti-CEA single-chain Fvs: improved targeting by non-covalent dimers.

BACKGROUND: Genetic engineering can produce novel antibody fragments with improved properties for applications such as tumor targeting in vivo. OBJECTIVES: To produce stable monomeric (27 kDa) and dimeric (55 kDa) forms of a single-chain Fv (scFv) from the anti-carcinoembryonic antigen (anti-CEA) antibody T84.66, and assess the targeting and biodistribution properties in an animal model. STUDY DESIGN: ScFv were constructed with either a 28 or 14 amino acid connecting peptide and expressed by secretion from E. coli. Following affinity purification, proteins were characterized by gel electrophoresis and mass spectrometry. Binding properties were assessed by size exclusion HPLC after incubation with antigen, and affinities determined by surface plasmon resonance. The shorter linker favored formation of dimers (and higher multimers) which showed unusual stability. ScFv were radiolabeled with 125I for tumor targeting and biodistribution studies of monomeric or dimeric forms were conducted in athymic mice bearing LS174T human colorectal carcinoma xenografts. RESULTS: 125I-scFv monomers and dimers targeted exhibited rapid clearance kinetics in tumor-bearing mice. Nevertheless, the anti-CEA scFvs targeted very well to xenografts, leading to high tumor: normal organ ratios (greater than 20:1 at 24 h) for both forms. Tumor localization of the non-covalent dimers was much higher than monomers, reaching 10-15% injected dose per gram at 1 h. CONCLUSION: Non-covalent dimers of scFv (also known as diabodies) are stable, easy to produce and show excellent targeting as compared to monomeric scFv, probably due to increased mass and valency.

Animals↗
PubMed1995

gamma-Interferon administration after 90yttrium radiolabeled antibody therapy: survival and hematopoietic toxicity studies.

PURPOSE: Hematopoietic toxicity is the dose-limiting factor for radioimmunotherapeutic regimens. Cytokines have been shown to decrease hematopoietic toxicity in animals exposed to whole-body irradiation. The purpose of this study was to investigate the effects of murine gamma-interferon (gamma-IFN) on survival and hematopoietic toxicity in mice treated with high dose 90yttrium labeled anticarcinoembryonic antigen (CEA) monoclonal antibody. METHODS AND MATERIALS: Balb/c nu/nu mice were injected intravenously with 250 Ci 90Y-T84.66 (a murine anti-CEA monoclonal antibody). Thirty thousand units of gamma-IFN was administered i.v. 24 h later. Control mice received either 250 Ci 90Y-T84.66 alone or 30,000 units gamma-IFN alone. Survival, antibody biodistribution, and bone marrow histologic studies were then performed. RESULTS: Only 7% of the animals treated with 90Y-T84.66 survived up to 40 days posttreatment, when the study was terminated. In contrast, 52% of the mice treated with both 90Y-T84.66 and gamma-IFN survived 40 days posttherapy. No toxic deaths were seen in the control group administered gamma-interferon alone. Histologic examination of the bone marrow of animals receiving 90Y-T84.66 and gamma-IFN showed cellular depletion of 40-70% of the hematopoietic cells by 48 h. Cell depletion was 50-70% and 20% by 72 h and 8 days posttherapy, respectively. The marrow of the 90Y-T84.66-treated control group was depleted to a level of 50-80% at 48 h, and remained depleted at 90% at 72 h and 8 days posttherapy. No marrow cell reduction was seen in the gamma-IFN-only treated group. Biodistribution studies showed no alterations in antibody biodistribution or kinetics that could account for the changes in bone marrow toxicity after gamma-IFN. CONCLUSION: These results demonstrate that gamma-IFN can reduce the hematologic toxicity resulting from high dose radioimmunotherapy. Histologic studies of bone marrow suggest that gamma-IFN acts primarily to accelerate myelorestoration of the bone marrow. Further studies exploring the use of gamma-IFN as an adjunct to radioimmunotherapy are therefore warranted.

Animals↗
PubMed1994

Continuous infusion chemotherapy as a radiation-enhancing agent for yttrium-90-radiolabeled monoclonal antibody therapy of a human tumor xenograft.

Radioimmunotherapy using monoclonal antibodies is a promising investigational treatment modality for solid tumors. Use of radiation-enhancing agents could significantly impact on the therapeutic response of this treatment. We evaluated the potential interaction of a known radiation-enhancing agent, 5-fluorouracil (5-FU), with the radioimmunotherapeutic effect of a yttrium-90 (90Y)-labeled monoclonal antibody in a human adeno-carcinoma xenograft. Athymic mice were inoculated subcutaneously with the human colon carcinoma cell line LS-174T. All mice had intraperitoneal 3-day osmotic infusion pumps placed by laparotomy. Half of the pumps were filled with 0.9% saline solution and half were filled with a solution containing 5-FU. Three activity levels of 90Y-radiolabeled CC49 antibody were injected into tail veins of the mice. Each activity level was injected into a group of animals with saline-filled pumps and a group with 5-FU-filled pumps. A significant interaction between treatment group and time was found suggesting that the rate of tumor growth for the group of animals receiving 90Y at 100 microCi plus 5-FU compared to the group of animals receiving 90Y alone was significantly delayed (P = 0.0055), showing a radiation enhancing effect by 5-FU. These results suggest that the addition of the radiation-enhancing agent 5-FU to radiolabeled antibody may increase the ability to treat solid tumors. Further investigations with other antibodies, radionuclides, and tumor models are indicated.

Adenocarcinoma, Mucinous↗
PubMed1991

Potential artifact for the increase of tumor associated antigens in serum samples from patients injected with monoclonal antibodies.

The administration of [131I]B72.3 MAb for both diagnostic and therapeutic purposes is followed by the development of human anti-mouse antibodies (HAMA) in approx. 70% of patients receiving i.v. doses of MAb above 1 mg. The presence of HAMA in circulation interferes in the detection of the tumor-associated glycoprotein TAG-72 using the CA 72-4 RIA. We have reported elsewhere (Ferroni et al., 1990) that heat treatment at 90 degrees C, pH 6.5, for 15 min is capable of precipitating and/or inactivating HAMA without causing any significant loss in antigen recovery. Furthermore, the removal of the interfering activity leads to a more correct evaluation of TAG-72 serum levels in HAMA-positive serum samples and to a continued use of TAG-72 in the follow-up of patients undergoing MAb-based clinical protocols.

Animals↗
PubMed1991

Survivors of Hodgkin's disease: prevention of sequelae.

Increasing numbers of patients are surviving Hodgkin's disease in their youth, creating an ever larger cohort who need careful attention to long-term preventive medicine in their older years. Vigilance is especially needed for those who received laparotomy, splenectomy, and irradiation for early stage I through stage III disease, the majority of whom are destined to be long-term survivors. With the frequent migration of the young, these patients often fall under the care of a physician other than their original oncologist. The diligent internist, oncologist, emergency room physician, and general practitioner can avoid several simple pitfalls in the long-term care of these young patients now entering middle age.

Adult↗
PubMed1991

Radiation therapy versus combination chemotherapy in the treatment of early-stage Hodgkin's disease: seven-year results of a prospective randomized trial.

The study population included 136 patients with stage IA, IB, IIA, IIB, or IIIA1 Hodgkin's disease. The median follow-up is 7.5 years. Among the 30 patients with peripheral IA disease, all patients achieved a complete response (CR) with radiation therapy, and no patient has relapsed. Patients of other stages were randomized to receive radiation therapy or mechlorethamine, vincristine, procarbazine, and prednisone (MOPP). Among the 51 patients randomized to receive radiation therapy, 49 (96%) achieved complete remission, 17 (35%) have relapsed, and 10 (20%) have died. Fifty-two of the 54 (96%) assessable patients randomized to receive MOPP obtained CRs, seven (13%) have relapsed, and four (7%) have died. The projected 10-year disease-free survival of patients randomized to receive radiation therapy is 60%; for those randomized to receive MOPP, it is 86% (P2 = .009 in favor of MOPP). The projected 10-year overall survival for patients randomized to radiation therapy is 76%, and for MOPP-treated patients it is 92% (P2 = .051 in favor of MOPP). When the randomized patients with massive mediastinal disease or stage IIIA1 disease were excluded from the analysis, the disease-free (67% for radiation v 82% for MOPP) and overall survival (85% for radiation v 90% for MOPP) were not significantly different between the two arms. Subset analysis showed significant superiority of MOPP in the treatment of the following patient groups: stage IIIA1 or massive mediastinal disease, no B symptoms, initial erythrocyte sedimentation rate greater than 20 mm, four or more sites of disease, and younger than age 40 years. Preliminary analysis of this ongoing study shows that MOPP chemotherapy is at least as effective as radiation therapy in the treatment of the specific groups of early-stage Hodgkin's disease patients randomized. The final assessment of these two diverse treatment options will depend largely on the long-term survival and the incidence of early- and late-treatment complications for which patients are continuing to be observed.

Adolescent↗
PubMed1990

Development of non-Hodgkin lymphoma in a cohort of patients with severe human immunodeficiency virus (HIV) infection on long-term antiretroviral therapy.

OBJECTIVE: To describe the incidence of non-Hodgkin lymphoma in a group of patients with symptomatic human immunodeficiency virus (HIV) infection receiving long-term dideoxynucleoside antiretroviral therapy. DESIGN: We examined the records of all patients with the acquired immunodeficiency syndrome (AIDS) or severe AIDS-related complex who were entered into three long-term phase I trials of zidovudine (azidothymidine, AZT) or zidovudine-containing regimens at the National Cancer Institute between 1985 and 1987. SETTING: The Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland. PARTICIPANTS: Fifty-five HIV-infected patients with AIDS or severe AIDS-related complex. MEASUREMENTS AND MAIN RESULTS: Eight of fifty-five patients (14.5%; 95% CI, 6.5% to 26.7%) developed a high-grade non-Hodgkin lymphoma of B-cell type, a median of 23.8 months (range, 13 to 35 months) after starting antiretroviral treatment. Using the method of Kaplan and Meier, the estimated probability of developing lymphoma by 30 months of therapy was 28.6% (CI, 13.7% to 50.3%) and by 36 months, 46.4% (CI, 19.6% to 75.5%). The patients who developed lymphoma had less than 100 T4 cells/mm3 for a median of 17.8 months (range, 7 to 35 months) and less than 50 T4 cells/mm3 for a median of 15.3 months (range, 5.5 to 35 months) before the diagnosis. All patients presented with non-Hodgkin lymphoma in extranodal sites, and two developed primary brain involvement in the setting of Toxoplasma infection. CONCLUSION: Patients with symptomatic HIV infection who survive for up to 3 years on antiretroviral therapy may have a relatively high probability of developing non-Hodgkin lymphoma. Prolonged survival in the setting of profound immunosuppression with substantial T4-cell depletion is probably an important factor in the development of these lymphomas. However, a direct role of therapy itself cannot be totally discounted. As improved therapies for the treatment of HIV infection and its complications result in prolonged survival, non-Hodgkin lymphoma may become an increasingly significant problem.

AIDS-Related Complex↗
PubMed1990

Innovations that influence the pharmacology of monoclonal antibody guided tumor targeting.

Tumor targeting by monoclonal antibodies (MAbs) can be enhanced by (a) increasing the percentage of injected dose taken up by the tumor and/or (b) increasing the tumor:nontumor ratios. Several groups have demonstrated that one can increase tumor to nontumor ratios by the use of antibody fragments or the administration of second antibodies. Several other modalities are also possible: (a) the use of recombinant interferons to up-regulate the expression of specific tumor associated antigens such as carcinoembryonic antigen or TAG-72 on the surface of carcinoma cells and thus increase MAb tumor binding has proved successful in both in vitro and in vivo studies; (b) the intracavitary administration of MAbs. Recent studies have demonstrated that when radiolabeled B72.3 is administered i.p. to patients with carcinoma of the peritoneal cavity, it localizes tumor masses with greater efficiency than does concurrent i.v. administered antibody. Studies involving the comparative pharmacology of intracavitary administration of radiolabeled MAb in patients and several animal models will be discussed; (c) it has been reported that prior exposure of hepatoma to external beam radiation will increase radiolabeled MAb tumor targeting. We and others have not been able to duplicate this phenomenon with a human colon cancer xenograft model and radiolabeled MAbs to two different colon carcinoma associated antigens. The possible reasons for these differences will be discussed; (d) the cloning and expression of recombinant MAbs with human constant regions and subsequent size modification constructs will also undoubtedly alter the pharmacology of MAb tumor binding in both diagnostic and therapeutic applications.

Animals↗
PubMed1990

A staging of lymphomas: practical thoughts on impractical practices.

Staging of lymphomas represents a discipline different from the staging of other cancers. In lymphomas, the purpose of staging rests more on the establishment of consistent standards by which we can evaluate changes in treatment programs, rather than a means of deciding on an appropriate treatment for an individual patient. In comparing treatments from different times and centers, one should exercise care to ensure the true comparability of the study groups. Frequently, errors are encountered in the comparison of surgical versus clinical staging. Other pitfalls occur when new, more sensitive diagnostic tests result in the clinical upstaging of selected groups leading to the improvement in subgroups but not affecting the treatment results for the group as a whole.

Humans↗