996 resultados para Antibodies, Monoclonal -- therapeutic use


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Behçet's disease (BD) is universally recognized as a multisystemic inflammatory disease of unknown etiology with chronic course and unpredictable exacerbations: its clinical spectrum varies from pure vasculitic manifestations with thrombotic complications to protean inflammatory involvement of multiple organs and tissues. Treatment has been revolutionized by the progressed knowledge in the pathogenetic mechanisms of BD, involving dysfunction and oversecretion of multiple proinflammatory molecules, chiefly tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, and IL-6. However, although biological treatment with anti-TNF-α agents has been largely demonstrated to be effective in BD, not all patients are definite responders, and this beneficial response might drop off over time. Therefore, additional therapies for a subset of refractory patients with BD are inevitably needed. Different agents targeting various cytokines and their receptors or cell surface molecules have been studied: the IL-1 receptor has been targeted by anakinra, the IL-1 by canakinumab and gevokizumab, the IL-6 receptor by tocilizumab, the IL12/23 receptor by ustekinumab, and the B-lymphocyte antigen CD-20 by rituximab. The aim of this review is to summarize all current experiences and the most recent evidence regarding these novel approaches with biological drugs other than TNF-α blockers in BD, providing a valuable addition to the actually available therapeutic armamentarium.

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Individualized treatment regimens may reduce patient burden with satisfactory patient outcomes in neovascular age-related macular degeneration. Intravitreal anti-VEGF drugs are the current gold standard. Fixed monthly injections offer the best visual outcome but this regimen is not commonly followed outside clinical trials. A PRN regimen requires monthly visits where the patient is treated in the presence of signs of lesion activity. Therefore, an early detection of reactivation of the disease with immediate retreatment is crucial to prevent visual acuity loss. Several trials suggest that "treat and extend" and other proactive regimens provide a reasonable approach. The rationale of the proactive regimens is to perform treatment anticipating relapses or recurrences and therefore avoid drops in vision while individualizing patient followup. Treat and extend study results in significant direct medical cost savings from fewer treatments and office visits compared to monthly treatment. Current data suggest that, for one year, PRN is less expensive, but treat and extend regimen would likely be less expensive for subsequent years. Once a patient is not a candidate to continue with treatment, he/she should be sent to an outpatient unit with adequate resources to follow nAMD patients in order to reduce the burden of specialized ophthalmologist services.

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OBJECTIVE: In 2005-2006, several studies noted an increased risk of cardiovascular birth defects associated with maternal use of paroxetine compared with other antidepressants in the same class. In this study, the authors sought to determine whether paroxetine was associated with an increased risk of cardiovascular defects in infants of women exposed to the drug during the first trimester of pregnancy. METHOD: From teratology information services around the world, the authors collected prospectively ascertained, unpublished cases of infants exposed to paroxetine early in the first trimester of pregnancy and compared them with an unexposed cohort. The authors also contacted the authors of published database studies on antidepressants as a class to determine how many of the women in those studies had been exposed to paroxetine and the rates of cardiovascular defects in their infants. RESULTS: The authors were able to ascertain the outcomes of 1,174 infants from eight services. The rates of cardiac defects in the paroxetine group and in the unexposed group were both 0.7%. The rate in the database studies (2,061 cases from four studies) was 1.5%. CONCLUSIONS: Paroxetine does not appear to be associated with an increased risk of cardiovascular defects following use in early pregnancy, as the incidence in more than 3,000 infants was well within the population incidence of approximately 1%.

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OBJECTIVES We aimed to investigate potential associations between human leukocyte antigen (HLA) class I and class II alleles and the development of anaphylactic/anaphylactoid reactions in patients with multiple sclerosis (MS) treated with natalizumab. METHODS HLA class I and II genotyping was performed in patients with MS who experienced anaphylactic/anaphylactoid reactions and in patients who did not develop infusion-related allergic reactions following natalizumab administration. RESULTS A total of 119 patients with MS from 3 different cohorts were included in the study: 54 with natalizumab-related anaphylactic/anaphylactoid reactions and 65 without allergic reactions. HLA-DRB1*13 and HLA-DRB1*14 alleles were significantly increased in patients who developed anaphylactic/anaphylactoid reactions (p M-H = 3 × 10(-7); odds ratio [OR]M-H = 8.96, 95% confidence interval [CI] = 3.40-23.64), with a positive predictive value (PPV) of 82%. In contrast, the HLA-DRB1*15 allele was significantly more represented in patients who did not develop anaphylactic/anaphylactoid reactions to natalizumab (p M-H = 6 × 10(-4); ORM-H = 0.2, 95% CI = 0.08-0.50), with a PPV of 81%. CONCLUSIONS HLA-DRB1 genotyping before natalizumab treatment may help neurologists to identify patients with MS at risk for developing serious systemic hypersensitivity reactions associated with natalizumab administration.

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Tumor angiogenesis is an essential step in tumor progression and metastasis formation. Suppression of tumor angiogenesis results in the inhibition of tumor growth. Recent evidence indicates that vascular integrins, in particular alpha V beta 3, are important regulators of angiogenesis, including tumor angiogenesis. Integrin alpha V beta 3 antagonists, such as blocking antibodies or peptides, suppress tumor angiogenesis and tumor progression in many preclinical tumor models. The potential therapeutic efficacy of extracellular integrin antagonists in human cancer is currently being tested in clinical trials. Selective disruption of the tumor vasculature by high doses of tumor necrosis factor (TNF) and interferon gamma (IFN-gamma), and the antiangiogenic activity of nonsteroidal anti-inflammatory drugs are associated with the suppression of integrin alpha V beta 3 function and signaling in endothelial cells. Furthermore, expression of isolated integrin cytoplasmic domains disrupts integrin-dependent adhesion, resulting in endothelial cell detachment and apoptosis. These results confirm the critical role of vascular integrins in promoting endothelial cell survival and angiogenesis and suggest that intracellular targeting of integrin function and signaling may be an alternative strategy to extracellular integrin antagonists for the therapeutic inhibition of tumor angiogenesis.

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We present the long-term results of 18 chemotherapy relapsed indolent (N = 12) or transformed (N = 6) NHL patients of a phase II anti-CD20 (131)I-tositumomab (Bexxar) therapy study. The biphasic therapy included two injections of 450 mg unlabelled antibody combined with (131)I-tositumomab once as dosimetric and once as therapeutic activity delivering 75 or 65 cGy whole-body radiation dose to patients with normal or reduced platelet counts, respectively. Two patients were not treated due to disease progression during dosimetry. The overall response rate was 81% in the 16 patients treated, including 50% CR/CRu and 31% PR. Median progression free survival of the 16 patients was 22.5 months. Median overall survival has not been reached after a median observation of 48 months. Median PFS of complete responders (CR/CRu) has not been reached and will be greater than 51 months. Short-term side effects were mainly haematological and transient. Among the relevant long-term side effects, one patient previously treated with CHOP chemotherapy died from secondary myelodysplasia. Four patients developed HAMA. In conclusion, (131)I-tositumomab RIT demonstrated durable responses especially in those patients who achieved a complete response. Six of eight CR/CRu are ongoing after 46-70 months.

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A monoclonal antibody (MAb) HL-C5, which bound selectively to cells of the myeloid lineage tested, was derived from a fusion between P3/NS2/1-AG8 myeloma cells and splenocytes from a mouse immunized with cells of the promyelocytic leukemia line HL-60. Among a panel of 29 human cell lines derived from either hematopoietic or solid tumors, MAb HL-C5 was found to react exclusively with cells from the five differentiated acute myeloid leukemia lines, HL-60, ML1, ML2, ML3, KG-1B and not with the less differentiated myeloid lines. Fluorescence-activated cell sorter analysis of normal bone marrow samples confirmed that the reactivity of MAb HL-C5 was limited to myeloid cells, from the promyelocytic stage of differentiation to the mature granulocytes. Indirect immunoperoxidase staining of cytocentrifuge preparations of normal bone marrow and peripheral blood leukocytes confirmed these results and showed that MAb HL-C5 stained neutrophils but not eosinophils or basophils. The antigen recognized by HL-C5 was recovered in the upper phase of chloroform-methanol-water lipid extracts prepared from HL-60 cells. By competitive binding experiments, it was found that MAb HL-C5 recognizes the same antigenic determinant as MAb WGHS 29-1, which has been reported to react with glycolipids containing the sugar sequence lacto-N-fucopentaose 111. Autoradiographs of thin layer chromatograms of HL-60 glycolipid extracts which were revealed by incubation with MAb HL-C5 or WGHS 29-1 followed by the addition of 125I-labelled rabbit anti-mouse immunoglobulin antibody confirmed that the two MAbs reacted with the same or structurally very similar glycolipids.

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In rodents and nonhuman primates subjected to spinal cord lesion, neutralizing the neurite growth inhibitor Nogo-A has been shown to promote regenerative axonal sprouting and functional recovery. The goal of the present report was to re-examine the data on the recovery of the primate manual dexterity using refined behavioral analyses and further statistical assessments, representing secondary outcome measures from the same manual dexterity test. Thirteen adult monkeys were studied; seven received an anti-Nogo-A antibody whereas a control antibody was infused into the other monkeys. Monkeys were trained to perform the modified Brinkman board task requiring opposition of index finger and thumb to grasp food pellets placed in vertically and horizontally oriented slots. Two parameters were quantified before and following spinal cord injury: (i) the standard 'score' as defined by the number of pellets retrieved within 30 s from the two types of slots; (ii) the newly introduced 'contact time' as defined by the duration of digit contact with the food pellet before successful retrieval. After lesion the hand was severely impaired in all monkeys; this was followed by progressive functional recovery. Remarkably, anti-Nogo-A antibody-treated monkeys recovered faster and significantly better than control antibody-treated monkeys, considering both the score for vertical and horizontal slots (Mann-Whitney test: P = 0.05 and 0.035, respectively) and the contact time (P = 0.008 and 0.005, respectively). Detailed analysis of the lesions excluded the possibility that this conclusion may have been caused by differences in lesion properties between the two groups of monkeys.

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SUMMARY: Reluctance has been expressed about treating chronic hepatitis C in active intravenous (IV) drug users (IDUs), and this is found in both international guidelines and routine clinical practice. However, the medical literature provides no evidence for an unequivocal treatment deferral of this risk group. We retrospectively analyzed the direct effect of IV drug use on treatment outcome in 500 chronic hepatitis C patients enrolled in the Swiss Hepatitis C Cohort Study. Patients were eligible for the study if they had their serum hepatitis C virus (HCV) RNA tested 6 months after the end of treatment and at least one visit during the antiviral therapy, documenting the drug use status. Five hundred patients fulfilled the inclusion criteria (199 were IDU and 301 controls). A minimum exposure to 80% of the scheduled cumulative dose of antivirals was reached in 66.0% of IDU and 60.5% of controls (P = NS). The overall sustained virological response (SVR) rate was 63.6%. Active IDU reached a SVR of 69.3%, statistically not significantly different from controls (59.8%). A multivariate analysis for treatment success showed no significant negative influence of active IV drug use. In conclusion, our study shows no relevant direct influence of IV drugs on the efficacy of anti-HCV therapy among adherent patients.

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Recombinant human tumour necrosis factor (TNF) has a selective effect on angiogenic vessels in tumours. Given that it induces vasoplegia, its clinical use has been limited to administration through isolated limb perfusion (ILP) for regionally advanced melanomas and soft tissue sarcomas of the limbs. When combined with the alkylating agent melphalan, a single ILP produces a very high objective response rate. In melanoma, the complete response (CR) rate is around 80% and the overall objective response rate greater than 90%. In soft tissue sarcomas that are inextirpable, ILP is a neoadjuvant treatment resulting in limb salvage in 80% of the cases. The CR rate averages 20% and the objective response rate is around 80%. The mode of action of TNF-based ILP involves two distinct and successive effects on the tumour-associated vasculature: first, an increase in endothelium permeability leading to improved chemotherapy penetration within the tumour tissue, and second, a selective killing of angiogenic endothelial cells resulting in tumour vessel destruction. The mechanism whereby these events occur involves rapid (of the order of minutes) perturbation of cell-cell adhesive junctions and inhibition of alphavbeta3 integrin signalling in tumour-associated vessels, followed by massive death of endothelial cells and tumour vascular collapse 24 hours later. New, promising approaches for the systemic use of TNF in cancer therapy include TNF targeting by means of single chain antibodies or endothelial cell ligands, or combined administration with drugs perturbing integrin-dependent signalling and sensitizing angiogenic endothelial cells to TNF-induced death.

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OBJECTIVES: To compare the use of guideline-recommended medical and interventional therapies in older and younger patients with acute coronary syndromes (ACSs). DESIGN: Prospective cohort study. SETTING: Fifty-five hospitals in Switzerland. PARTICIPANTS: Eleven thousand nine hundred thirty-two patients with ACS enrolled between March 1, 2001, and June 30, 2006. ACS definition included ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina pectoris (UA). MEASUREMENTS: Use of medical and interventional therapies was determined after exclusion of patients with contraindications and after adjustment for comorbidities. Multivariate logistic regression models were used to calculate odds ratios (ORs) per year increase in age. RESULTS: Elderly patients were less likely to receive acetylsalicylic acid (OR=0.976, 95% confidence interval (CI)=0.969-0.980) or beta-blockers (OR=0.985, 95% CI=0.981-0.989). No age-dependent difference was found for heparin use. Elderly patients with STEMI were less likely to receive percutaneous coronary intervention (PCI) or thrombolysis (OR=0.955, 95% CI=0.949-0.961). Elderly patients with NSTEMI or UA less often underwent PCI (OR=0.943, 95% CI=0.937-0.949). CONCLUSION: Elderly patients across the whole spectrum of ACS were less likely to receive guideline-recommended therapies, even after adequate adjustment for comorbidities. Prognosis of elderly patients with ACS may be improved by increasing adherence to guideline-recommended medical and interventional therapies.

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Treatment of B cell lymphoma patients with MoAbs specific for the common B cell marker (CD20) has shown a good overall response rate, but the number of complete remissions is still very low. The use of MoAbs coupled to radioisotopes can improve the results, but induces undesirable myelodepression. As an alternative, we proposed to combine the specificity of MoAbs with the immunogenicity of T cell epitopes. We have previously shown that an anti-Ig lambda MoAb coupled to an MHC class II-restricted universal T cell epitope peptide P2 derived from tetanus toxin induces efficient lysis of a human B cell lymphoma by a specific CD4+ T cell line. Here we demonstrate that the antigen presentation properties of the MoAb peptide conjugate are maintained using a MoAb directed against a common B cell marker, CD19, which is known to be co-internalized with the B cell immunoglobulin receptor. In addition, we provide evidence that B cell lysis is mediated by the Fas apoptosis pathway, since Fas (CD95), but not tumour necrosis factor receptor (TNFr) or TNF-related receptors, is expressed by the target B cells, and FasL, but not perforin, is expressed by the effector T cells. These results show that B cell lymphomas can be 'foreignized' by MoAb-peptide P2 conjugates directed against the common B cell marker CD19 and eliminated by peptide P2-specific CD4+ T cells, via the ubiquitous Fas receptor. This approach, which bridges the specificity of passive antibody therapy with an active T cell immune response, may be complementary to and more efficient than the present therapy results with unconjugated chimeric anti-CD20 MoAbs.

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BACKGROUND: Tenofovir (TDF) use has been associated with proximal renal tubulopathy, reduced calculated glomerular filtration rates (cGFR) and losses in bone mineral density. Bone resorption could result in a compensatory osteoblast activation indicated by an increase in serum alkaline phosphatase (sAP). A few small studies have reported a positive correlation between renal phosphate losses, increased bone turnover and sAP. METHODS: We analysed sAP dynamics in patients initiating (n = 657), reinitiating (n = 361) and discontinuing (n = 73) combined antiretroviral therapy with and without TDF and assessed correlations with clinical and epidemiological parameters. RESULTS: TDF use was associated with a significant increase of sAP from a median of 74 U/I (interquartile range 60-98) to a plateau of 99 U/I (82-123) after 6 months (P < 0.0001), with a prompt return to baseline upon TDF discontinuation. No change occurred in TDF-sparing regimes. Univariable and multivariable linear regression analyses revealed a positive correlation between sAP and TDF use (P < or = 0.003), but no correlation with baseline cGFR, TDF-related cGFR reduction, changes in serum alanine aminotransferase (sALT) or active hepatitis C. CONCLUSIONS: We document a highly significant association between TDF use and increased sAP in a large observational cohort. The lack of correlation between TDF use and sALT suggests that the increase in sAP is because of the bone isoenzyme and indicates stimulated bone turnover. This finding, together with published data on TDF-related renal phosphate losses, this finding raises concerns that TDF use could result in osteomalacia with a loss in bone mineral density at least in a subset of patients. This potentially severe long-term toxicity should be addressed in future studies.

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Two 131-Iodine radiolabelled monoclonal antibodies were used to perform tomoscintigraphy in 42 patients: 11 patients bearing medullary thyroid cancers and 19 patients bearing gastrointestinal cancers received an antibody directed against carcino-embryonic antigen; 12 patients bearing gastro-intestinal cancers received an antibody directed against a non circulating antigen expressed by human colorectal cancers cell lines. Tomoscintigraphy is particularly useful for analysing the complex biodistribution of radiolabelled antibodies and the low contrast images encountered in immunoscintigraphy; the problems related to the true positive rate and to the clinical specificity of the method are discussed.