Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.1 (asparaginase)
 2,695 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) who was treated with alpha-interferon (alpha-IFN) is reported. After the treatment, the number of Ph+ bone marrow (BM) cells decreased gradually and the intensity of the rearranged major breakpoint cluster region (M-BCR) gene became faint; however, a lymphoblastic crisis developed about 1 year later. At the time of the blast crisis, the rearranged M-BCR band was detected, indicating that the blast crisis clone was derived from CML cells. The patient was treated with a combination of vincristine, prednisolone, daunorubicin, and L-asparaginase, and a hematologic remission was obtained. During the remission status, no rearranged M-BCR fragment was detected by conventional Southern analysis. Thus, the hematologic and genetic alteration in this case appeared to be identical to Ph+ acute leukemia with M-BCR rearrangement. The current case therefore indicates that alpha-IFN can reduce the proportion of Ph+ cells, but is unable to prevent blast crisis. Furthermore, the quantitative reduction of the cell population with a Ph chromosome may have some effects in modifying the genetic manifestations and clinical features of Ph+ CML, e.g., the delay in the appearance of the blast crisis.
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PMID:Restoration of cytogenetically normal marrow cells after remission of lymphoblastic crisis in a case of Ph positive CML treated with alpha-interferon. 155 Oct 82

In contrast to the accepted general assumption that polyethylene glycol (PEG) is non-immunogenic and non-antigenic, animal studies clearly showed that uricase, ovalbumin and some other PEGylated agents can elicit antibody formation against PEG (anti-PEG). In humans, anti-PEG may limit therapeutic efficacy and/or reduce tolerance of PEG-asparaginase (PEG-ASNase) in patients with acute lymphoblastic leukemia and of pegloticase in patients with chronic gout, but did not impair hyposensitization of allergic patients with mPEG-modified ragweed extract or honeybee venom or the response to PEG-IFN in patients with hepatitis C. Of major importance is the recent finding of a 22 - 25% occurrence of anti-PEG in healthy blood donors, compared with a very low 0.2% occurrence two decades earlier. This increase may be due to an improvement of the limit of detection of antibodies during the years and to greater exposure to PEG and PEG-containing compounds in cosmetics, pharmaceuticals and processed food products. These results raise obvious concerns regarding the efficacy of PEG-conjugated drugs for a subset of patients. To address these concerns, the immunogenicity and antigenicity of approved PEGylated compounds should be carefully examined in humans. With all these data in hand, patients should be pre-screened and monitored for anti-PEG prior to and throughout a course of treatment with a PEGylated compound. Finally, protein conjugates with the poorly immunogenic hydroxy-PEG sequence or other hydrophilic polymers are in early phases of development and may represent an alternative to immunogenic PEGylated proteins.
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PMID:Antibodies against polyethylene glycol in healthy subjects and in patients treated with PEG-conjugated agents. 2293 Oct 49

All biotherapeutics have the potential to induce an immune response. This immunological response is complex and, in addition to antibody formation, involves T cell activation and innate immune responses that could contribute to adverse effects. Integrated immunogenicity data analysis is crucial to understanding the possible clinical consequences of anti-drug antibody (ADA) responses. Because patient- and product-related factors can influence the immunogenicity of a therapeutic protein, a risk-based approach is recommended and followed by most drug developers to provide insight over the potential harm of unwanted ADA responses. This paper examines mitigation strategies currently implemented and novel under investigation approaches used by drug developers. The review describes immunomodulatory regimens used in the clinic to mitigate deleterious ADA responses to replacement therapies for deficiency syndromes, such as hemophilia A and B, and high risk classical infantile Pompe patients (e.g., cyclophosphamide, methotrexate, rituximab); novel in silico and in vitro prediction tools used to select candidates based on their immunogenicity potential (e.g., anti-CD52 antibody primary sequence and IFN beta-1a formulation); in vitro generation of tolerogenic antigen-presenting cells (APCs) to reduce ADA responses to factor VIII and IX in murine models of hemophilia; and selection of novel delivery systems to reduce in vivo ADA responses to highly immunogenic biotherapeutics (e.g., asparaginase). We conclude that mitigation strategies should be considered early in development for biotherapeutics based on our knowledge of existing clinical data for biotherapeutics and the immune response involved in the generation of these ADAs.
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PMID:Approaches to Mitigate the Unwanted Immunogenicity of Therapeutic Proteins during Drug Development. 2808 96