Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Campath-1 (CDw52) antibodies (IgM and IgG2b) have been used in vitro and in vivo for control of GVHD and prevention of rejection following bone marrow transplantation. Results of 951 patients with malignant disease transplanted from HLA-matched siblings are reported. Both Campath-1M and Campath-1G are shown to be effective when used in vitro for prevention of graft-versus-host disease (GVHD). Graft failure was reduced by addition of cyclosporin A (CsA) post-transplant and possibly also by total lymphoid irradiation (TLI) pre-transplant. However, treatment of the recipient with Campath-1G to deplete residual lymphocytes was more effective, reducing the incidence of graft failure from 21% to 9% (in the absence of CsA). GVHD was virtually eliminated and leukaemia-free survival was improved. However, the risk of relapse was increased by T cell depletion, certainly in CML and to a lesser extent in AML. Addition of donor T cells to the depleted bone marrow or early post-transplant restored the risks of GVHD, graft failure and relapse to much the same as without T cell depletion. One problem associated with the use of Campath-1G in vivo was a significant delay (by up to 7 days) in neutrophil engraftment. This was unlikely to be caused by toxicity to progenitor cells and we argue that small numbers of lymphocytes may be required to assist early engraftment, possibly by cytokine production. If this problem can be overcome, T cell depletion of donor and recipient may be a good alternative to conventional GVHD prophylaxis for matched sibling transplants, resulting in a superior quality of life for the survivors. It is also likely to be particularly beneficial in transplants for non-malignant diseases and transplants from unrelated donors.
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PMID:Control of graft-versus-host disease and graft rejection by T cell depletion of donor and recipient with Campath-1 antibodies. Results of matched sibling transplants for malignant diseases. 777 29

Recent data from the CAMPATH users group are reported. Different protocols have been tested using the CD52 antibodies Campath-1M and Campath-1G for prevention of GVHD and graft rejection in allogeneic transplants from both sibling and volunteer unrelated donors. Leukaemia relapse remains a significant problem for patients with CML, but in other diseases the recent results using T cell depletion appear to be as good as, or better than, published data with conventional GVHD prophylaxis. In addition, the morbidity and mortality associated with chronic GVHD are substantially reduced. Future collaborative studies to consolidate these findings include a randomised trial of the humanised antibody Campath-1H organised under the auspices of the EBMT. There are also plans to carry out experimental studies using Campath-1 antibodies to deplete T cells from peripheral blood stem cell harvests.
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PMID:Recent results using CAMPATH-1 antibodies to control GVHD and graft rejection. 870 78

The prophylactic use of T cell depletion (TCD) strategies for the prevention of graft-versus-host disease (GVHD) following allogeneic stem cell transplantation remains widespread. Initial reports of high incidence of graft rejection after TCD BMT led to a move away from this approach but improved conditioning regimens have reduced this risk substantially. The use of TCD has also been associated with higher relapse risk post-BMT although the success of donor leukocyte infusion (DLI) as treatment for relapse has reduced this problem, especially in chronic myeloid leukaemia (CML). Currently the use of TCD BMT is increasing particularly due to the relative increase in BMT from non-related donors for whom TCD is the optimal GVHD prophylaxis. However, doubts remain over the long-term effect on the reconstituted immune system of recipients of TCD BMT, particularly in adult recipients. In this study we have undertaken a detailed sequential analysis in 23 patients who received allo-grafts from HLA-identical sibling donors after high-dose chemo/radiotherapy for acute or chronic leukaemia. Of these patients, 11 received non-manipulated grafts, five received 'partially TCD' (PTCD) and a further seven received 'fully TCD' (FTCD) bone marrow. T cell depletion was performed ex vivo by Campath-1M plus autologous serum as a source of complement. Partial TCD describes grafts with a T cell reduction of 1-2 log. Full TCD refers to grafts with a reduction of >2.5 log. The decision regarding the optimal degree of TCD was clinical and was based upon the perceived relative risk of relapse based upon the disease and remission status. All patients were monitored for up to 12 months post-BMT with regard to reconstitution of T and NK cell subsets. T cell depletion at either level was associated with a slower recovery of CD4 cells. This was most marked in the FTCD recipients and lasted throughout the period of study. CD8 cell recovery was also slower in the TCD recipients but this normalised throughout the 12 months post-BMT. The ratio of CD45RA+:CD45RO+ increased in all recipients after month 3. This suggests that a degree of extra-thymic T cell maturation can occur in recipients of allogeneic BMT. NK cell recovery was more rapid in the TCD recipients and these differences were maintained throughout the first year.
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PMID:The effect of T cell depletion with Campath-1M on immune reconstitution after chemotherapy and allogeneic bone marrow transplant as treatment for leukaemia. 957 7

We have analyzed the factors associated with engraftment in 216 recipients of T-cell depleted allogeneic HLA identical sibling marrow transplants using Campath 1 monoclonal antihuman lymphocyte (CD52) antibodies. The patient population consisted of 168 patients with hematologic malignancies, 26 with severe aplastic anemia (SAA), and 22 with hemoglobinopathies, half of whom received marrow treated in vitro with Campath-1M (IgM) and half received marrow with Campath-1G (IgG2b isotype). Patients with durable engraftment had fast hematopoietic recovery: SAA patients reached ANC > 0.5 x 10(6)/L on Day 14; those with leukemia attained ANC > 0.5 x 10(6)/L on Days 18, 17, and 15 for ANLL, ALL and CML respectively, while patients with thalasemia reached ANC > 0.5 x 10(6)/L on Day 21. Overall, 24 patients (17 with leukemia, 4 with SAA, and 3 with thalassemia) suffered graft failure: 10 patients (all grafted with Campath-1M) rejected their grafts, while 14 others (9 grafted with Campath-1M, and 5 with 1G isotype) never engrafted (p = 0.009). Multivariate analysis revealed that neither pretransplant protocol, nor stage of disease or type of antibody used, donor sex and ABO match had any impact on engraftment. The variables favorably associated with engraftment were older age (p = 0.030, RR = 1.016) and CFU-GM number (p = 0.013, RR = 1.001). Patients with ANLL or SAA had a better chance to engraft (p = 0.027, RR = 1.400; and p = 0.003, RR = 2.677, respectively) compared to patients with thalassemia (p = 0.001, RR = 0.551). A higher concentration of Campath-1 antibody in vitro and in vivo adversely affected engraftment. Our data show that satisfactory engraftment can be achieved in patients transplanted with Campath-1 treated marrow allografts. However, despite the measures undertaken to prevent rejection, graft failure still poses a problem. Further pretransplant immunosuppression and perhaps more selective T-cell depletion may reduce the increased graft failure in these patients.
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PMID:Engraftment of marrow allografts treated with Campath-1 monoclonal antibodies. 1039 Jan 97

Unrelated donor (UD) transplantation is the only potentially curative therapy for many leukaemia patients but is associated with a high mortality and morbidity. We sought to identify factors that could be optimised to improve outcome following UD transplantation in adults. Data was retrospectively analysed on 55 patients sequentially receiving UD transplants for CML or acute leukaemia (AL), all of whom received serotherapy for the prevention of GVHD and rejection. All patients received standard conditioning regimens. The first 28 patients transplanted also received combined pre- and post-transplant serotherapy with Campath 1G (days -5 to +5) and standard dose CsA plus MTX as GVHD prophylaxis (protocol 1). The subsequent 27 patients received a 5-day course of pre-transplant serotherapy alone either with ATG (CML patients) or Campath 1G (AL patients) on days -5 to -1 inclusive, with high-dose CSA plus MTX (protocol 2). The incidence of acute GVHD was low with no patient receiving either protocol developing > grade 2 disease. The use of protocol 2 and the administration of a bone marrow cell dose above the median (2.17 x 10(8)/kg) were the most important factors predicting engraftment (P = 0.03 and P = 0.001, respectively) but this only remained significant for cell dose in multivariate analysis (P = 0.03). Overall survival for the group was 45% at 3 years and was influenced by both age (P = 0.02) and disease status at transplantation (P = 0.001). Receiving a cell dose above the median was also associated with a trend towards better survival (P = 0.08), due primarily to a reduction in the TRM to 8.2% compared with 54.5% in those receiving a lower cell dose (P = 0.002). We conclude that pre-transplant serotherapy alone is highly effective at preventing acute GVHD following UD BMT and that additional post-transplant serotherapy does not confer any benefit. Furthermore, a high marrow cell dose infused has a major effect in reducing transplant related mortality following UD BMT.
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PMID:The effect of the serotherapy regimen used and the marrow cell dose received on rejection, graft-versus-host disease and outcome following unrelated donor bone marrow transplantation for leukaemia. 1072 85

A significant number of patients who relapse after allogeneic stem cell transplantation (SCT) for chronic myeloid leukemia (CML) will achieve sustained remissions after treatment with interferon-alpha, second transplants, or donor lymphocyte infusions (DLI) from the original stem cell donor. Because leukemia-free survival (LFS) is at present defined as survival without evidence of relapse at any time posttransplant, patients who relapse but are then restored to complete remission are treated as failures when estimating LFS. We have established a new category of LFS, termed current LFS (CLFS), which we define as survival without evidence of leukemia at the time of most recent assessment. To gauge the contribution of treatment for relapse to the efficacy of allogeneic SCT in the management of CML in chronic phase, we compared conventional LFS and CLFS in 189 consecutive patients who underwent SCT over a 7-year period with a minimum follow-up of 3 years. Patients with sibling donors (n = 111) received cyclosporine and methotrexate as prophylaxis for graft versus host disease; patients with unrelated donors (n = 78) also received Campath-1G or 1H as intravenous T-cell depletion. The 5-year LFS defined conventionally was 36% (CI: 29% to 43%) versus a 5-year CLFS of 49% (CI: 36% to 62%). This new method of defining LFS confirms the view that appropriate "salvage" therapy, principally DLI, makes a major contribution to the capacity of allogeneic SCT to produce long-term LFS in patients who receive SCT for CML and emphasizes the importance of redefining LFS to take account of successful treatment of relapse.
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PMID:Estimating leukemia-free survival after allografting for chronic myeloid leukemia: a new method that takes into account patients who relapse and are restored to complete remission. 1089 35

Conventional cytotoxic therapy of hematologic malignancies is often associated with significant morbidity. This morbidity is often due to the lack of specificity for hematopoietic cells. Therefore, the concept of targeted therapy for patients with hematologic malignancies has received attention for many years. The goal of monoclonal antibody therapy is to target specific cell surface antigens on malignant hematopoietic cells, while sparing normal cells and tissues. Currently, monoclonal antibodies are being evaluated for their cytotoxic effects as well as their ability to deliver toxic agents or radiation. Rituximab, a chimeric anti-CD20 antibody, has shown response rates of approximately 50% with minimal toxicity in patients with refractory indolent lymphoma. Campath-1H (anti-CD52) has shown encouraging results in patients previously treated for chronic lymphocytic leukemia, with response rates up to 33%, although with significant toxicity. Anti-CD33 antibodies are being used to deliver cytotoxic agents, such as calicheamicin to patients with acute myeloid leukemia with response rates up to 30%. In addition, anti-CD33 and anti-CD45 antibodies have been used to deliver radiation directly to leukemic cells. (131)I-labeled anti-CD45 antibodies are being studied in combination with conventional preparative regimens in patients receiving bone marrow transplantation. Lastly, the therapeutic agent STI571 (signal transduction inhibitor 571) has demonstrated the capability of targeting specific molecular abnormalities seen in hematologic malignancies. STI571 targets the tyrosine kinase activity of the bcr-abl fusion protein seen in chronic myeloid leukemia. STI571 has induced complete hematologic responses in up to 98% of patients evaluated in clinical trials.
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PMID:Cell surface antigen and molecular targeting in the treatment of hematologic malignancies. 1200 80

Significant advances have been made in the development of targeted interventions for hematologic malignancies. Progress has been made in defining the molecular pathogenesis of human leukemias. Data indicate that nonrandom, somatically acquired translocations, inversions, and other abnormalities occur in many acute leukemias. In the treatment of acute promyelocytic leukemia (APL), targeted therapy with all-trans retinoic acid (ATRA) and anthracycline-based chemotherapy leads to dramatic improvements in disease-free survival. Imatinib mesylate, a signal transduction inhibitor that inhibits tyrosine kinase activity, the protein product of the ABL proto-oncogene, has remarkable activity in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL). Farnesyltransferase inhibitors (FTIs), a promising class of agents that target multiple pathways including Ras proteins, are potential anticancer therapy for a wide range of malignancies, including leukemias and myelodysplastic syndromes (MDS). There also is evidence that recombinant human erythropoietin therapy (r-HuEPO) can benefit patients with chronic lymphocytic leukemia (CLL), multiple myeloma, and lymphomas. This supplement will discuss advances in our understanding of human leukemias, including the use of unconjugated monoclonal antibodies such as Campath-1H (Wellcome, Beckenham, UK, and Ilex Oncology, San Antonio, TX) and rituximab and immunoconjugates such as gemtuzumab ozogamicin and BL-22. Although these novel therapies are beginning to fulfill their promise, continued research efforts are needed to determine the optimal role of targeted therapy in acute and chronic leukemias.
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PMID:Advancing the treatment of hematologic malignancies through the development of targeted interventions. 1244 45

We studied the outcome of 24 peripheral blood stem cell (PBSC) graft recipients, who were T-cell depleted (TCD) with either 20 mg (n = 14) or 10 mg (n = 10) Campath-1H in vitro, in comparison with a retrospective cohort of 23 unmanipulated (UM) PBSC recipients. While the neutrophil engraftment was similar, the platelet engraftment occurred earlier in the TCD group (d 11 vs 14). The incidence of acute and chronic graft-versus-host-disease (GVHD) was 8.7% and 4.4% in the TCD group, respectively, compared with 47.7% and 56.3% in UM group (P < 0.001). In the TCD group, 5/6 chronic myeloid leukaemia (CML) and 4/18 non-CML patients relapsed (vs 0/6 and 3/17 in UM group, P = 0.06). All four molecular or cytogenetic relapses of CML were disease-free survivors following donor lymphocyte infusion. There was no difference in the incidence of serious infection between the TCD and UM groups and the lymphocyte recovery at 100 d was comparable. In the TCD cohort, the lymphocyte recovery was quicker in the 10 mg Campath-1H group. The non-relapse mortality (19.1%vs 66.3%) and 3 year survival (73.1 vs 19.2) were improved in the TCD group (P = 0.05). Thus elimination of late mortalities related to chronic GVHD and a rapid immune reconstitution, limiting either infection or relapse related deaths, contributed to an improved outcome following T-cell depletion with Campath-1H "in the bag".
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PMID:T-cell depletion with Campath-1H "in the bag" for matched related allogeneic peripheral blood stem cell transplantation is associated with reduced graft-versus-host disease, rapid immune constitution and improved survival. 1267 Mar 40

The study comprised 37 consecutive patients who underwent transplantation with a Campath-1H in vitro T cell-depleted granulocyte colony-stimulating factor-mobilized peripheral blood stem cell graft from an HLA-identical sibling, followed 24 hours later by an unmanipulated graft. Acute graft-versus-host disease (GVHD) was limited to grade I to II, whereas chronic graft-versus-host disease occurred in 9 patients, mostly (n = 7) with limited disease. Molecular relapses (8 chronic myeloid leukemia [CML] and 1 non-Hodgkin lymphoma) that occurred not earlier than the sixth month after transplantation were treated with donor lymphocyte infusion (DLI), which induced complete remission in all but 1 CML patient with persistent very low BCR-ABL molecular levels. With a median follow-up of 54 months (range, 29-84 months), the actuarial 5-year overall survival, disease-free survival, and transplant-related mortality are 78% (95% confidence interval [CI], 52%-88%), 78% (95% CI, 52%-86%), and 6% (95% CI, 1.5%-32%), respectively. All CML patients are alive and free of disease. The results of this prospective, nonrandomized study show that incomplete T-cell depletion in vitro with Campath-1H (in combination with DLI for molecular relapses in CML) may decrease the incidence of GVHD and transplant-related mortality with no adverse effect on disease-free survival. The described method decreases the number of T cells to an extent that severe GVHD is prevented while relapse is postponed to a time when the patient can be treated with DLI without severe side effects.
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PMID:Can only partial T-cell depletion of the graft before hematopoietic stem cell transplantation mitigate graft-versus-host disease while preserving a graft-versus-leukemia reaction? A prospective phase II study. 1639 74


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