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Andrew Raubitschek

Publications and source records attributed to Andrew Raubitschek.

14 recordsLinked to original sources
PubMed2006

Phase I single-dose study of intracavitary-administered iodine-131-TM-601 in adults with recurrent high-grade glioma.

PURPOSE: TM-601 binds to malignant brain tumor cells with high affinity and does not seem to bind to normal brain tissue. Preclinical studies suggest that iodine-131 (131I) -TM-601 may be an effective targeted therapy for the treatment of glioma. We evaluated the safety, biodistribution, and dosimetry of intracavitary-administered 131I-TM-601 in patients with recurrent glioma. PATIENTS AND METHODS: Eighteen adult patients (17 with glioblastoma multiforme and one with anaplastic astrocytoma) with histologically documented recurrent glioma and a Karnofsky performance status of > or = 60% who were eligible for cytoreductive craniotomy were enrolled. An intracavitary catheter with subcutaneous reservoir was placed in the tumor cavity during surgery. Two weeks after surgery, patients received a single dose of 131I-TM-601 from one of three dosing panels (0.25, 0.50, or 1.0 mg of TM-601), each labeled with 10 mCi of 131I. RESULTS: Intracavitary administration was well tolerated, with no dose-limiting toxicities observed. 131I-TM-601 bound to the tumor periphery and demonstrated long-term retention at the tumor with minimal uptake in any other organ system. Nonbound peptide was eliminated from the body within 24 to 48 hours. Only minor adverse events were reported during the 22 days after administration. At day 180, four patients had radiographic stable disease, and one had a partial response. Two of these patients further improved and were without evidence of disease for more than 30 months. CONCLUSION: A single dose of 10 mCi 131I-TM-601 was well tolerated for 0.25 to 1.0 mg TM-601 and may have an antitumoral effect. Dosimetry and biodistribution from this first trial suggest that phase II studies of 131I-TM-601 are indicated.

Adult↗
PubMed2005

Treatment of refractory Hodgkin's lymphoma patients with an iodine-131-labeled murine anti-CD30 monoclonal antibody.

PURPOSE: Hodgkin's lymphoma (HL) has been demonstrated to be a good target for immunotherapy since lymphocyte activation markers such as CD30 are expressed in high numbers on the malignant cells. Thus, we developed a new radioimmunoconjugate consisting of the murine anti-CD30 monoclonal antibody (MAb) Ki-4 labeled with iodine-131 ((131)I). PATIENTS AND METHODS: The biodistribution of (131)I-Ki-4 was assessed via dosimetry after preinfusion of 5 mg native Ki-4 followed by 250 to 300 MBq (131)I-labeled Ki-4. Whole-body scintigraphy was performed 1 hour, 24 hours, 48 hours, 72 hours, and 6 days after the infusion. Dosimetry was calculated using the programs NucliDose ICON-IDL (version 5.0.2; Siemens, Erlanger, Germany) and MIRDOSE (version 3.1; Oak Ridge National Laboratories; Oak Ridge, TN). The therapeutic dose was given on day 8 after preinfusion of unlabeled Ki-4. RESULTS: We treated 22 patients with relapsed or refractory CD30-positive HL. Preinfusion of 5 mg native Ki-4 was sufficient to bind the soluble CD30. Imaging demonstrated localization of involved areas measuring 5 cm in diameter or more in four patients and 2.5 cm in one patient. Patients received total body doses of 0.035 Gy to 0.99 Gy. Acute toxicity was mild with grade 1 fatigue in 19 of 22 assessable patients. Seven patients experienced grade 4 degrees hematotoxicity 4 to 8 weeks after treatment. Response included one complete remission, five partial remissions, and three minor responses. CONCLUSION: Treatment with (131)I-Ki-4 is effective but can be associated with severe hematotoxicity.

Adolescent↗
PubMed2005

A phase 1/2 trial of high-dose yttrium-90-ibritumomab tiuxetan in combination with high-dose etoposide and cyclophosphamide followed by autologous stem cell transplantation in patients with poor-risk or relapsed non-Hodgkin lymphoma.

We conducted a phase 1/2 trial of high-dose 90Y-ibritumomab tiuxetan in combination with high-dose etoposide (VP-16) 40 to 60 mg/kg (day -4) and cyclophosphamide 100 mg/kg (day -2) followed by autologous stem cell transplantation (ASCT) in 31 patients with CD20+ non-Hodgkin lymphoma (NHL). Patients underwent dosimetry (day -21) with 5 mCi (185 MBq) 111In-ibritumomab tiuxetan following 250 mg/m2 rituximab, followed a week later by 90Y-ibritumomab tiuxetan to deliver a target dose of 1000 cGy to highest normal organ. Bone marrow biopsy was done on day -7 to estimate radiation dose and stem cells were reinfused when the radiation dose was estimated to be less than 5 cGy. The median 90Y-ibritumomab tiuxetan dose was 71.6 mCi (2649.2 MBq; range, 36.6-105 mCi; range, 1354.2-3885 MBq). Histology included follicular lymphoma (n = 12), diffuse large B-cell (n = 14), and mantle cell (n = 5). The median number of prior chemo-therapy treatments was 2. The treatment was well tolerated. The median times to reach an absolute neutrophil count greater than 500/microL and platelet count more than 20,000/microL were 10 days and 12 days, respectively. There were 2 deaths and 5 relapses. At a median follow-up of 22 months, the 2-year estimated overall survival and relapse-free survival rates are 92% and 78%, respectively. We conclude that high-dose 90Y-ibritumomab tiuxetan can be combined safely with high-dose etoposide and cyclophosphamide without an increase in transplant-related toxicity or delayed engraftment.

Adult↗
PubMed2005

Cell membrane-specific epitopes on CD30: Potentially superior targets for immunotherapy.

Because CD30 is highly expressed on Hodgkin's lymphoma and anaplastic large cell lymphoma, it is a promising target for immunotherapy. Soluble CD30, the extracellular domain of CD30 that is shed from the cells, can reduce the effects of CD30-targeting agents by competitive binding. In this study, we identified two epitopes on membrane-associated CD30 that are missing on soluble CD30 probably because of a conformational change upon shedding. These epitopes are potentially superior targets for immunotherapy because targeting them should be free from the competitive effects of soluble CD30. We studied 27 anti-native CD30 mAbs that were assigned to 8 different topographical epitopes. Soluble CD30 was prepared from culture supernatants of L540 cells or Karpas 299 cells. In an ELISA, the mAbs to two epitopes, Ep2 (amino acids 107-153) and Ep7 (amino acids 282-338), showed less than a 2% average cross-reactivity to soluble CD30 compared with a CD30-Fc fusion protein. In addition, these mAbs bound to CD30 on cells in the presence of an excess of soluble CD30. These epitopes (Ep2 and Ep7) are, therefore, more efficiently presented on cell-associated CD30 than on soluble CD30 (membrane-specific epitopes). Also, soluble CD30 in the sera of mice bearing L540 tumors did not form immune complexes with the membrane-specific mAbs analyzed by size-exclusion chromatography. In contrast, mAbs to the other epitopes reacted with both soluble CD30 and membrane CD30. Our results suggest that it may be possible to find membrane-specific epitopes on other immunotherapy target molecules.

Animals↗
PubMed2005

An anti-CD20-IL-2 immunocytokine is highly efficacious in a SCID mouse model of established human B lymphoma.

We have engineered an anti-CD20-interleukin 2 (IL-2) immunocytokine (ICK) based on the Leu16 anti-CD20 antibody and have deimmunized both the variable (V) regions as well as the junction between the heavy (H) chain constant region and IL-2. Mutations were made to remove potential T-cell epitopes identified by in silico binding to major histocompatibility complex (MHC) class II molecules. The resulting immunocytokine, DI-Leu16-IL-2, retained full anti-CD20 activity as assessed by fluorescence-activated cell-sorting (FACS) analysis, and had enhanced antibody-dependent cellular cytotoxicity (ADCC) effector function relative to the DI-Leu16 antibody or control anti-CD20 antibody (rituximab). In a severe combined immunodeficient (SCID) mouse model of disseminated, residual lymphoma, anti-CD20-IL-2 immunocytokines based on Leu16 were far more effective at a dose of 0.25 mg/kg than anti-CD20 antibody given at 25/mg/kg, despite a shorter half-life of the ICK. Anti-CD20-IL-2 was also far more effective than a control ICK targeted to an antigen with greatly reduced expression on Daudi tumor cells, or various combinations of anti-CD20 antibodies and IL-2. Antitumor activity of DI-Leu16-IL-2 was shown to partially but not entirely depend on Fc receptor (R) binding, suggesting that ADCC and targeting of IL-2 both play roles in the mechanism of tumor clearance. Based on these animal models, DI-Leu16-IL-2 could offer therapeutic potential for patients with CD20 positive lymphoma. Clinical trials are currently under development.

Animals↗
PubMed2005

Biophotonic cytotoxicity assay for high-throughput screening of cytolytic killing.

We have developed a highly sensitive biophotonic luciferase assay as an alternative to (51)Cr-release for assessment of cell-mediated cytotoxicity. The luciferin/ATP-dependent luminescent signal of target cells stably or transiently transfected with a firefly luciferase reporter gene (fLuc:Zeo) linearly correlates with viable target cell number. Upon incubation of fLuc:Zeo(+) target cells with CD8(+) CTLs, a rapid decrease in bioluminescence was detected that correlated with antigen-specific target cell lysis. The levels of specific lysis measured by (51)Cr-release assays correlated with the attenuation in biophotonic target cell signal, thus validating this approach as a sensitive and accurate method for the measurement of cytolysis. We show that this luminescent-based cytolytic assay (LCA) is amenable for high-throughput screening of effector cell cytolytic activity, allows for the rate of cytolysis to be measured in a single micro-plate, and permits the multiplexing of cytolytic killing with other lymphocyte functional assays such as cytokine release. Importantly, this method accurately measures the cytolytic killing of target cells that are either stably or transiently transfected with a fLuc reporter gene, and thus is ideal for monitoring cytolysis of both primary autologous and immortalized target cell lines. The versatility of the non-radioactive, high-throughput, biophotonic cytolytic assay should make this method an attractive alternative to chromium-release for quantifying effector cell cytolytic activity.

CD8-Positive T-Lymphocytes↗
PubMed2005

Imaging glioma extent with 131I-TM-601.

UNLABELLED: TM-601, a 36-amino-acid peptide, selectively binds to glioma cells but not normal brain parenchyma. A phase I/II clinical trial of intracavitary 131I-TM-601 in adult patients with recurrent high-grade glioma was performed to determine the biodistribution and toxicity of this potential therapy. We evaluated imaging and biodistribution data from this trial to assess whether 131I-TM-601 might be useful in determining tumor extent. METHODS: Adult patients with recurrent high-grade gliomas underwent tumor resection, implantation of an intracavitary reservoir, and a single-dose injection of 370 MBq (10 mCi) 131I-TM-601 (0.25-1.0 mg of 131I-TM-601) 2-4 wks after surgery. Total-body planar scans and whole-brain SPECT scans were obtained on days 0, 1, 2, 3, and 6-8 after injection. Postresection MR images were coregistered to the SPECT scans using image analysis software. Analysis of the rate of radioactive decay and biologic elimination from the body and at the cavity site was performed. T1-weighted with gadolinium contrast (T1-Wc), T2-weighted (T2), and SPECT volumes were estimated by stereological Cavalieri sections and compared for overlap. RESULTS: Nonbound 131I-TM-601 was eliminated by 48 h after injection with the remaining radiolabeled peptide bound to tumor for at least 6-8 d. Biologic decay rates from 24 to 168 h after injection were only slightly shorter than the physical decay of 131I (6.3 vs. 8.0 d). A comparison of tumor volume estimates using all 3 imaging parameters indicated that 131I-TM-601-determined tumor volumes more closely paralleled T2 volumes than T1-Wc volumes. Overlap between coregistered MRI and SPECT scans corroborated the presence of radiolabeled peptide in the vicinity of infiltrating tumor up to 168 h after injection. CONCLUSION: 131I-TM-601 provides a reliable estimate for primary tumor extent. Further modification of this radiopeptide with other better imaging isotopes may provide an important tool for determining tumor extent and differentiating regions of viable tumor from necrosis.

Adult↗
PubMed2004

Specific recognition and killing of glioblastoma multiforme by interleukin 13-zetakine redirected cytolytic T cells.

The interleukin (IL) 13 receptor alpha2 (IL13Ralpha2) is a glioma-restricted cell-surface epitope not otherwise detected within the central nervous system. Here, we describe a novel approach for targeting glioblastoma multiforme (GBM) with IL13Ralpha2-specific cytolytic T cells (CTLs) by their genetic modification to express a membrane-tethered IL13 cytokine chimeric T-cell antigen receptor, or zetakine. Our prototype zetakine incorporates an IL13 E13Y mutein for selective binding to IL13Ralpha2. Human IL13-zetakine(+)CD8(+) CTL transfectants display IL13Ralpha2-specific antitumor effector function including tumor cell cytolysis, T(C)1 cytokine production, and zetakine-regulated autocrine proliferation. The E13Y amino acid substitution of the IL13 mutein of the zetakine endows CTL transfectants with the capacity to discriminate between IL13Ralpha2(+) GBM targets from targets expressing IL13Ralpha1. In vivo, the adoptive transfer of IL13-zetakine(+)CD8(+) CTL clones results in the regression of established human glioblastoma orthotopic xenografts. Pilot clinical trials have been initiated to evaluate the feasibility and safety of local-regional delivery of autologous IL13-zetakine redirected CTL clones in patients with recurrent GBM. Our IL13-zetakine is a prototype of a new class of chimeric immunoreceptors that signal through an engineered immune synapse composed of membrane-tethered cytokine muteins bound to cell-surface cytokine receptors on tumors.

Animals↗
PubMed2004

Cellular immunotherapy for follicular lymphoma using genetically modified CD20-specific CD8+ cytotoxic T lymphocytes.

Humoral immunotherapy using the monoclonal anti-CD20 antibody rituximab induces remissions in approximately 60% of patients with relapsed follicular lymphoma; however, most patients eventually relapse despite continued expression of CD20 on lymphoma cells. We have hypothesized that cellular immunotherapy targeting CD20(+) cells might provide a more effective mechanism for eliminating lymphoma cells than anti-CD20 antibodies and are therefore investigating the utility of cytotoxic T lymphocytes (CTL) genetically modified to target the CD20 antigen. Peripheral blood mononuclear cells were activated with anti-CD3 antibody (OKT3) and recombinant human interleukin-2 and electroporated with a plasmid containing a CD20-specific scFvFc:zeta chimeric T cell receptor gene and a neomycin phosphotransferase gene (neo(R)). Transfected cells were selected using the antibiotic G418 and cloned by limiting dilution. Using this approach, we have generated CD8(+) CTL clones with CD20-specific cytotoxicity, which specifically lysed CD20(+) target cells, including actual tumor cells from patients with follicular lymphoma, small lymphocytic lymphoma, splenic marginal zone lymphoma, diffuse large B cell lymphoma, and chronic lymphocytic leukemia. The CTL clones have been expanded to numbers sufficient for therapy ( approximately 10(9) cells). Our data indicate the feasibility of generating and expanding CD20-specific CTL and, for the first time, demonstrate that such CTL exhibit specific cytotoxicity against actual tumor cells isolated from patients with a variety of B lymphoid malignancies. In view of these promising findings, a Phase I clinical trial for relapsed follicular lymphoma is being initiated.

Antigens, CD20↗
PubMed2002

T-cell clones can be rendered specific for CD19: toward the selective augmentation of the graft-versus-B-lineage leukemia effect.

Relapse of B-lineage acute lymphoblastic leukemia (B-ALL) after allogeneic hematopoietic stem cell transplantation (HSCT) commonly results from the failure of a graft-versus-leukemia (GVL) effect to eradicate minimal residual disease. Augmenting the GVL effect by the adoptive transfer of donor-derived B-ALL-specific T-cell clones is a conceptually attractive strategy to decrease relapse rates without exacerbating graft-versus-host disease (GVHD). Toward this end, we investigated whether a genetic engineering approach could render CD8(+) cytotoxic T lymphocytes (CTLs) specific for tumor cells that express the B-cell lineage cell surface molecule CD19. This was accomplished by the genetic modification of CTLs to express a chimeric immunoreceptor composed of a CD19-specific single-chain immunoglobulin extracellular targeting domain fused to a CD3-zeta intracellular signaling domain. CD19-redirected CTL clones display potent CD19-specific lytic activity and chimeric immunoreceptor-regulated cytokine production and proliferation. Because B-ALL cells can evade T-cell/natural killer- cell recognition by down-regulation of cell surface accessory molecules that participate in the formation of a functional immunologic synapse, we compared the CD19-specific effector function of genetically modified CD8(+) CTLs toward CD19(+) cells with disparate levels of intercellular adhesion molecule 1 (ICAM-1), leukocyte function-associated antigen 1 (LFA-1), and LFA-3. We observed that recognition of B-lineage tumor lines by CD19-specific CTLs was not impaired by low levels of ICAM-1, LFA-1, and LFA-3 cell surface expression, a functional attribute that is likely a consequence of our high-affinity CD19-specific chimeric immunoreceptor. Furthermore, the CD19-specific CTLs could lyse primary B-ALL blasts. These preclinical observations form the basis for implementing clinical trials using donor-derived CD19-specific T-cell clones to treat or prevent relapse of B-ALL after allogeneic HSCT.

Adoptive Transfer↗
PubMedDate not supplied

Development and application of CD19-specific T cells for adoptive immunotherapy of B cell malignancies.

The graft-versus-leukemia (GVL)-effect achieved by donor-derived T cells arising from transplanted allogeneic hematopoietic stem cells or given as donor-leukocyte infusions (DLI) after allogeneic transplant, demonstrates that donor-derived T cells can eradicate B-lineage malignancies. However, graft-versus-host-disease (GVHD) occurring after allogeneic hematopoietic stem-cell transplant (HSCT) or polyclonal DLI can limit the efficacy of these interventions. This toxicity can be avoided by using autologous T cells and/or tumor-specific cytotoxic T lymphocytes (CTLs). To generate antigen-specific T cells that can be derived from the allogeneic donor or the patient, we have genetically manipulated T cells to express a CD19-specific chimeric immunoreceptor. This renders T cells specific for CD19, a cell surface molecule found on B-lineage leukemia and lymphoma. This review will demonstrate the redirected specificity of CD19-specific T cells and implementation of clinical trials using these cellular agents.

Antigens, CD19↗
PubMedDate not supplied

Combined radioimmunotherapy and chemotherapy of breast tumors with Y-90-labeled anti-Her2 and anti-CEA antibodies with taxol.

Because breast cancer cells often express either Her2/neu or carcinoembryonic antigen (CEA) or both, these tumor markers are good targets for radioimmunotherapy using Y-90-labeled antibodies. We performed studies on nude mice bearing xenografts from MCF7, a cell line that has low Her2 and CEA expression, to more accurately reflect the more usual situation in breast cancer. Although uptake of In-111 anti-CEA into tumors was lower than that for In-111-labeled anti-Her2, radioimmunotherapy (RIT) with Y-90 anti-CEA was equivalent to that of Y-90 anti-Her2. When either Y-90 antibody was combined with a split-dose treatment with Taxol, the antitumor effect was greater than with either agent alone. When Y-90 anti-CEA was combined with a single dose of Taxol, the results were equivalent to the split-dose regimen. RIT plus cold Herceptin had no additional effects on tumor size reduction over RIT alone. When animals were first treated with Y-90 anti-Her2 and imaged 1-2 weeks later with In-111 anti-CEA or anti-Her2, tumor uptake was higher for anti-CEA and improved over tumor uptake with no prior RIT. These results suggest that a split dose of RIT with anti-Her2 antibody followed by anti-CEA antibody would be more effective than a single dose of either. This prediction was partially confirmed in a controlled study comparing single- vs split-dose anti-Her2 RIT followed by either anti-Her2 or anti-CEA RIT. These studies suggest that combined RIT and Taxol therapy are suitable in breast cancers expressing either low amounts of Her2 or CEA, thus expanding the number of eligible patients for combined therapies. They further suggest that split-dose RIT using different combinations of Y-90-labeled antibodies is effective in antitumor therapy.

Animals↗
PubMedDate not supplied

Improved biodistribution and radioimmunoimaging with poly(ethylene glycol)-DOTA-conjugated anti-CEA diabody.

Diabodies are single chain antibody fragments (scFvs) that spontaneously form bivalent dimers of molecular size 50-55000. Radiolabeled diabodies are almost ideal tumor targeting agents due to their high avidity (bivalent) binding to tumor antigens and small size (50-55000) that leads to improved tumor-to-blood ratio compared to intact antibodies (150000). However, due to their high retention and metabolism in the kidney, radioiodine is the current radiolabel of choice for diabodies since radioiodine is rapidly excreted from the kidney once metabolized. We have previously shown that 111In-DOTA-diabody gives higher tumor uptake in nude mouse xenografts than 125I-diabody, but has extremely high kidney retention since its 111In-labeled metabolites are retained by and only slowly excreted from the kidney. When a diabody is conjugated to a bifunctional PEG-3400 derivative followed by reaction with cysteinyl-DOTA, the resulting product has an apparent molecular size of 75000 and a Stokes radius of 35 angstroms on size exclusion chromatography, compared to a Stokes radius of 25 angstroms for intact diabody. When radiolabeled, the conjugate gives high yields of 111In-labeled product, retains high immunoreactivity, and gives improved biodistributions (30-40%ID/g, 12-48 h) compared to 111In-DOTA-diabody (12-13%ID/g, 6-12 h). We show that the improved biodistribution is due to an increase in Stokes radius caused by the linear PEG-3400 since conjugation of diabody with multiple (PEG)12 linkers followed by reaction with cysteinyl-DOTA does not reduce kidney accumulation. We also show that 111In-cysteinyl-DOTA-PEG3400-diabody gives excellent tumor images in the nude mouse xenograft model and that 125I-PEG3400-diabody gives equivalent images to 125I-minibody (molecular size, 80000), but improved tumor-to-liver ratios, suggesting that this imaging agent can be used to image liver metastases.

Animals↗