Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006826 (cancer)
 1,092,456 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gemtuzumab ozogamicin (GO) is a chemotherapeutic agent that consists of a humanized anti-CD33 antibody (hP67.6) linked to N-acetyl-gamma calicheamicin 1,2-dimethyl hydrazine dichloride, a potent enediyne antitumor antibiotic. GO was approved conditionally by the Federal Drug Administration in May 2000 as single-agent therapy for first recurrence of acute myeloid leukemia (AML) in a subset of older patients. Data on studies in AML with GO-based regimens have been reported rapidly in addition to new observations on the target antigen, CD33. These data indicate promising new areas of investigation with GO, including its application as maintenance therapy in patients with AML and as an induction and/or maintenance agent in patients with acute promyelocytic leukemia;, and they also have highlighted challenges in the development of GO, particularly its association with hepatic venoocclusive disease. In vitro data on the mechanism of action of GO may be particularly helpful in the design of future clinical studies.
Cancer 2003 Nov 15
PMID:Gemtuzumab ozogamicin in the treatment of acute myeloid leukemia. 1460 Oct 78

Multicenter phase II trials with Gemtuzumab Ozogamicin (GO/Mylotarg), consisting of a CD33 antibody linked to the cytotoxic drug calicheamicin, have shown a 30% overall response rate in relapsed acute myeloid leukemia patients. However, no clear correlation was observed between CD33 expression on leukemic blasts and response to GO therapy. We analyzed the CD33 specificity of GO-induced cell death and the effect of GO on CD33-negative malignancies. We demonstrate that lysis induced by clinically relevant GO concentrations is partially CD33 mediated, and that efficient non-CD33-mediated GO uptake can occur via endocytosis. In agreement with these results, we observed GO-mediated death of human CD33-negative acute lymphoblastic leukemia cells both in vitro and in vivo in an NOD/SCID mouse model. Finally, sensitivity to GO-induced cell death was at least partially determined by the activation status of leukemic cells, with cells in activated phases of the cell cycle being most effective in both CD33-specific GO internalization, renewed expression of CD33 molecules, and non-CD33-mediated GO uptake via endocytosis. In conclusion, these data provide mechanistic insight into the efficacy of GO in CD33-positive as well as in CD33-negative malignancies with endocytic capacity, and provide a rationale for the use of GO in the treatment of malignancies with endocytic capacity.
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PMID:Internalization and cell cycle-dependent killing of leukemic cells by Gemtuzumab Ozogamicin: rationale for efficacy in CD33-negative malignancies with endocytic capacity. 1461 14

Monoclonal antibodies have become an important treatment modality in cancer therapy. Genetically engineered chimaeric and humanised antibodies have demonstrated activity against a variety of tumours. Whereas the humanised anti-CD33 monoclonal antibody HuM195 has only modest activity against overt acute myeloid leukaemia (AML), it can eliminate minimal residual disease detectable by reverse transcription-polymerase chain reaction in acute promyelocytic leukaemia. High-dose radioimmunotherapy with beta-particle-emitting isotopes targeting CD33, CD45 and CD66 can potentially allow intensification of antileukaemic therapy before bone marrow transplantation. Conversely, alpha-particle immunotherapy with isotopes such as bismuth-213 or actinium-225 offers the possibility of selective tumour cell kill while sparing surrounding normal cells. Targeted chemotherapy with the anti-CD33-calicheamicin construct gemtuzumab ozogamicin has produced remissions as a single agent in patients with relapsed AML and appears promising when used in combination with standard chemotherapy in the treatment of newly diagnosed AML.
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PMID:Antibody-based treatment of acute myeloid leukaemia. 1468 Apr 72

Treatment of patients with therapeutic monoclonal antibodies (mAbs) such as rituximab (Rituxan), an anti-CD20 mAb, or trastuzumab (Herceptin), an anti-HER2 mAb, have shown efficacy in clinical trials and have gained approval from the Food and Drug Administration (FDA). Mylotarg, an anti-CD33 mAb conjugated with the antibiotic calicheamicin has proven efficacious in the treatment of patients with acute myeloid leukemia and has also received FDA approval. However, the use of radionuclides to either augment inherent activity or to exploit the specific targeting properties has been a major development in mAb therapeutics. Radionuclide- bearing mAbs have recently been approved by the FDA; Zevalin, an anti-CD20 mAb armed with (90)Y and Bexxar, an anti-CD20 mAb armed with (131)I. This overview presents some background and some of the strategies pertaining to radiolabeled monoclonal antibody therapies with a focus on experiences reported for radiolabeled mAbs as evaluated in clinical trials.
Cancer Biol Ther 2004 Apr
PMID:Targeting of radio-isotopes for cancer therapy. 1497 24

Acute promyelocytic leukemia (APL) has become the most curable subtype of acute myeloid leukemia in adults. It represents the only established example of successful differentiation therapy. With current therapy which includes all-trans retinoic acid (ATRA) and anthracycline-based chemotherapy for induction, anthracycline-based consolidation and maintenance with ATRA and/or low-dose chemotherapy, approximately 75-85% of patients with acute promyelocytic leukemia (APL) remain alive and disease-free at 5 years, and most patients are likely to be cured, an unprecedented achievement in the field of hematologic malignancies. However, several causes for failure to be cured need to be addressed. The first is early death which occurs in approximately 10% and is frequently attributable to hemorrhage due to the characteristic coagulopathy. The second is relapse, particularly in intermediate- and high-risk patients. Analyses of new prognostic factors may permit refinement of current risk classification and identify patients warranting alternative therapy. Finally, long-term consequences of current treatment will be important to recognize, including delayed cardiomyopathy, extramedullary relapse related to sanctuary sites, and the potential for second malignancies. For patients who do relapse, arsenic trioxide appears to be the treatment of choice since the majority of patients achieve a second complete morphologic, cytogenetic, and even molecular remission. While some patients achieving a second complete remission have prolonged disease-free survival with consolidation and maintenance arsenic, high-dose chemotherapy with autologous hematopoietic stem cell transplantation appears to offer the highest likelihood of cure. Such a strategy or anti-CD33 antibodies, recently shown to be active in APL, might be considered for high-risk patients in first remission.
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PMID:Curative therapeutic approaches to APL. 1512 85

Antibody-targeted chemotherapy is a promising approach in patients with hematological malignancies. In particular, gemtuzumab ozogamicin (GO, formerly CMA-676), an anti-CD33 antibody linked to calicheamicin, has been approved for the treatment of elderly patients with acute myeloid leukemia (AML) in relapse. Nevertheless, no data are until now available concerning the possible efficacy of GO for myeloid sarcomas (MS). We treated with GO 24 AML patients, in 5 cases presenting with myeloid sarcomas of the skin or bones. The overall complete response rate was 21%. The median duration of response was 6 months. Four out of the 5 patients with myeloid sarcoma showed a regression of the masses, in two cases also obtaining a clearance of marrow blasts. The most common adverse events included thrombocytopenia, neutropenia, infections, elevation of bilirubin and hepatic transaminases. Notably, severe bleeding occurred in 5 cases (21%). VOD was documented in 1 case. We conclude that GO is effective as a single agent in AML and myeloid sarcomas. Further data are required to clarify the possible correlation between GO administration and occurrence of bleeding.
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PMID:Gemtuzumab ozogamicin for relapsed and refractory acute myeloid leukemia and myeloid sarcomas. 1522 37

Recently, anti-cancer antibodies have been launched in Japan and also immunoconjugates with a cytotoxic compound or a radioisotope have been launched in the USA. Gemtuzumab ozogamicin is a conjugate of anti-CD33 antibody and a cytotoxic calicheamicin derivative. After binding the CD33-positive leukemia cells, gemtuzumab ozogamicin is internalized and releases the calicheamicin derivative. The calichemicin derivative breaks DNA and kills the cells. Gemtuzumab ozogamicin was effective and well tolerated in clinical trials in patients with acute myeloid leukemia (AML) in relapse. It was approved in 2000 by the FDA, and Wyeth K.K. has submitted it as an anti-tumor drug for CD33 positive AML. Two kinds of immunoconjugates, anti-CD20 antibodies with radioisotopes, recently have been launched in the USA for CD20-positive non-Hodgkin's lymphoma. These conjugates showed efficacy in patients who are refractory to the conventional chemotherapies. Targeted therapy with the immunoconjugate that can deliver cytotoxic compounds to specific cells is promising for use in oncology.
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PMID:[Gemtuzumab ozogamicin and targeted cancer therapy]. 1522 19

Antibody-targeted chemotherapy is a therapeutic strategy in cancer therapy that involves a monoclonal antibody specific for a tumour-associated antigen, covalently linked via a suitable linker to a potent cytotoxic agent. Tumour-targeted delivery of a cytotoxic agent in the form of an immunoconjugate is expected to improve its antitumour activity and safety. Calicheamicin is a cytotoxic natural product isolated from Micromonospora echinospora that is at least 1000-fold more potent than conventional cytotoxic chemotherapeutics. Calicheamicin binds DNA in the minor groove and causes double-strand DNA breaks, leading to cell death. Immunoconjugates of calicheamicin targeted against tumour-associated antigens exhibit tumour-specific cytotoxic effects and cause regression of established human tumour xenografts in nude mice. Gemtuzumab ozogamicin is the first clinically validated cytotoxic immunoconjugate in which a humanised anti-CD33 antibody is linked to a derivative of calicheamicin. Gemtuzumab ozogamicin is indicated for the treatment of elderly patients with relapsed acute myeloid leukaemia. A similar conjugate, inotuzumab ozogamicin, is being evaluated at present in Phase I clinical trials in patients with non-Hodgkin's lymphoma. A number of tumour-targeted immunoconjugates of calicheamicin are being explored preclinically at present for their therapeutic applications.
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PMID:Tumour-targeted chemotherapy with immunoconjugates of calicheamicin. 1533 12

Acute myeloid leukemia (AML) has a poor prognosis due to treatment-resistant relapses. A humanized anti-CD33 antibody (Mylotarg) showed a limited response rate in relapsed AML. To discover novel AML antibody targets, we selected a panel of single chain Fv fragments using phage display technology combined with flow cytometry on AML tumor samples. One selected single chain Fv fragment broadly reacted with AML samples and with myeloid cell lineages within peripheral blood. Expression cloning identified the antigen recognized as C-type lectin-like molecule-1 (CLL-1), a previously undescribed transmembrane glycoprotein. CLL-1 expression was analyzed with a human anti-CLL-1 antibody that was generated from the single chain Fv fragment. CLL-1 is restricted to the hematopoietic lineage, in particular to myeloid cells present in peripheral blood and bone marrow. CLL-1 is absent on uncommitted CD34(+)/CD38(-) or CD34(+)/CD33(-) stem cells and present on subsets of CD34(+)/CD38(+) or CD34(+)/CD33(+) progenitor cells. CLL-1 is not expressed in any other tissue. In contrast, analysis of primary AMLs demonstrated CLL-1 expression in 92% (68 of 74) of the samples. As an AML marker, CLL-1 was able to complement CD33, because 67% (8 of 12) of the CD33(-) AMLs expressed CLL-1. CLL-1 showed variable expression (10-60%) in CD34(+) cells in chronic myelogenous leukemia and myelodysplastic syndrome but was absent in 12 of 13 cases of acute lymphoblastic leukemia. The AML reactivity combined with the restricted expression on normal cells identifies CLL-1 as a novel potential target for AML treatment.
Cancer Res 2004 Nov 15
PMID:C-type lectin-like molecule-1: a novel myeloid cell surface marker associated with acute myeloid leukemia. 1554 16

Monoclonal antibodies (mAbs) therapies have been introduced to the many kinds of malignancies. Rituximab (Rituxan), a chimeric anti-CD20 monoclonal antibody, has improved clinical outcome in the patients with B cell non-Hodgkin's lymphoma (NHL) as a single agent as well as combination with chemotherapies including CHOP and stem cell transplantation. The efficacy has been reported in the patients with follicular lymphoma as well as aggressive NHL. The expression of CD20 should be confirmed by immunopathological staining or flow cytometry before the treatment. Gemtuzumab ozogamicin (Mylotarg), calicheamicin conjugates of anti-CD33 mAb, has been introduced in the treatment of AML. CD33 is not expressed by immature pluripotent stem cells even though expressed on myeloid progenitor cells. Mylotarg is internalized via CD33, however, detouched calicheamicin might be pumped out by multi-drug resistant related p glycoprotains (p-gp). The expression of CD33 and p-gp should be analyzed by flow cytometry before the treatment. We should give another caution to tumor-lysis syndrome and veno-occlusive disease.
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PMID:[Monoclonal antibody therapy and laboratory medicine]. 1565 71


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