Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Radioimmunotherapy is an established and effective treatment in B-cell non-Hodgkin lymphoma (NHL). Currently, two radioimmunoconjugates (RICs) are approved for clinical use in the United States, ibritumomab tiuxetan and tositumomab. Both agents target the CD20 antigen on B-cell lymphoma cells. Although there are differences between these two agents, such as different murine monoclonal antibodies, radioisotopes, and dosimetry techniques, they share similar toxicity and efficacy profiles. These anti-CD20 RICs are active in patients who are refractory to single-agent rituximab, documenting the added value of the conjugated radioisotope. This review focuses on the current use of these agents in the treatment of previously untreated indolent NHL and relapsed/refractory and transformed NHL.
 ...
PMID:Radioimmunotherapy for B-cell non-Hodgkin lymphoma. 1672 34

Radioimmunotherapy (RIT) combines the targeting advantage of a monoclonal antibody with the radiosensitivity of non-Hodgkin lymphoma (NHL) cells. There are now two radioimmunoconjugates (RICs) - ibritumomab tiuxetan (Zevalin) and tositumomab (Bexxar) - that are approved by the FDA in the US for relapsed low-grade or follicular B-cell NHL. Both agents target the CD20 antigen on B-cell lymphoma cells. In relapsed disease, single doses of RIT produce an 80% overall response rate, with approximately 20% of patients achieving durable responses. RIT is very well tolerated and is delivered on an outpatient basis over 1 week. The only significant toxicity is reversible myelosuppression. Both RIT agents have demonstrated high anti-tumor activity in patients who are refractory to rituximab. Current trials are testing RIT as initial therapy with rituximab maintenance, as adjuvant therapy after chemotherapy, or in high-dose protocols with stem-cell support.
 ...
PMID:Radioimmunotherapy for B-cell non-Hodgkin lymphoma. 1699 75

Rituximab, a chimeric monoclonal antibody directed against CD20, has become a part of the standard therapy for patients with non-Hodgkin's lymphoma either in combination with other drugs or as a single agent. The CD20 antigen is expressed on 95% of B-cell lymphoma cells and normal B-cells but, is not found on precursor B-cells or stem cells. Rituximab is now approved for patients with diffuse large B-cell lymphoma when combined with standard CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone) or patients with follicular lymphoma who have failed first line chemotherapy. The monoclonal antibody is generally well tolerated. Most of the adverse events are infusion-associated, mild to moderate non-hematological toxicities. Severe respiratory adverse events have been infrequent. Here, we report two patients with non-Hodgkin's lymphoma in whom interstitial pneumonitis developed with rituximab therapy.
 ...
PMID:Two cases of interstitial pneumonitis caused by rituximab therapy. 1701 68

Tositumomab/iodine-131 tositumomab (Bexxar) and ibritumomab tiuxetan (Zevalin) are radioimmunoconjugates targeting the CD20 antigen. Both agents are approved in the United States for use in relapsed or refractory, indolent or transformed, B-cell lymphoma. These agents are well tolerated and have the highest levels of single-agent activity observed in these histologies. This review will summarize the key trials that led to approval of both I-131 tositumomab and ibritumomab tiuxetan, and then focus on four novel therapeutic concepts in radioimmunotherapy: retreatment, therapy of de novo indolent lymphoma, therapy of aggressive histologies, and incorporation in high-dose therapy programs utilizing autologous stem cell support.
 ...
PMID:Novel concepts in radioimmunotherapy for non-Hodgkin's lymphoma. 1739 83

Radioimmunotherapy, targeting the CD20 antigen, in B-cell lymphoma has clearly demonstrated efficacy and tolerability over the preceding 15 years. As a result, two products are available with Food and Drug Administration approval for marketing - Y(90) ibritumomab tiuxetan and I(131) tositumomab, given as the Zevalin and Bexxar therapeutic regimens, respectively. Both demonstrate high-response rates and durability of remission in the relapsed/refractory disease setting. Data are emerging regarding their utility as initial therapy, and furthermore, they are been investigated for use sequentially with chemotherapy, and in the myeloablative setting. As yet however, how to best use these agents in the clinical disease course remains uncertain.
 ...
PMID:Radioimmunotherapy for B-cell lymphoma: Y90 ibritumomab tiuxetan and I(131) tositumomab. 1753 15

Rituximab (Rit) was the first monoclonal antibody approved for therapeutic use in cancer patients. Rit is a chimeric mouse/human monoclonal antibody, consisting of the human IgG1 and k constant Fc region, and a mouse variable Fab region specific against the B-cell antigen CD20. Rit exerts its antilymphoma activity through many different mechanisms. Binding of antibody to CD20 antigen, provokes apoptosis through downstream signals that lead to caspase-3 activation. Complement activation by the Fc portion of the antibody results in complement-dependent cytotoxicity. However, the most effective mechanism of action seems to be antigen-dependent cellular cytotoxicity. Effector cytotoxic cells such as natural killer cells (NK) are activated after binding to the Fc portion of the anti-CD20 molecule. Activated NK cells kill the coated lymphoma cells with the use of granzyme-perforin system. More recently, pre-clinical data support the concept that Rituximab can provoke a vaccination-like effect. Finally in-vitro experiments and clinical trials have shown that co-administration of the antibody with cytotoxics confers a strong synergistic effect. The relative contribution of these mechanisms in vivo and in different lymphoma subtypes is not well known and remains to be further evaluated. Among the different histological groups, follicular lymphoma (FL) has been proven to be the most sensitive to Rit when used as a single agent, with overall response rates of 80% and 50% in untreated and previously treated patients, respectively. Moreover, Rit in combination with chemotherapy is superior to chemotherapy alone in terms of response rate and event-free survival, while early data indicate a significant prolongation in overall survival as well. Similarly, the addition of Rit to standard chemotherapy improves the disease-free and overall survival of patients with diffuse large B-cell lymphoma. There is no doubt that Rit represents one of the greatest achievements of biotechnology engineering. However, we need to understand better the mechanisms of its action as well as the mechanisms of resistance to Rit, in order to design more effective treatment modalities.
 ...
PMID:Monoclonal antibodies in the treatment of lymphoid malignancies. 1793 74

The aggressive lymphomas are potentially curable. The natural history of certain aggressive lymphomas has been altered by monoclonal antibody therapy. Targeted monoclonal antibody therapy to the CD20 antigen has altered the outcome of patients with diffuse large B-cell lymphoma in patients of all ages. Anti-CD20-based radioimmunoconjugates are being evaluated as radioimmunotherapy approaches in patients who have relapsed and in stem cell transplant settings. Antibody-directed therapy to the B-cell-specific antigen CD22 are ongoing. New approaches include different CD20 antibodies and an antibody to the CD40 antigen, which is a member of the tumor necrosis factor (TNF) receptor family, which is expressed on B-cells. Antibody therapy has been incorporated into CHOP (cyclophosphamide, adriamycin, vincristine, prednisone) therapy and other regimens such as EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin) and HyperCVAD (cyclophosphamide, vincristine, adriamycin, dexamethasone). Single-agent anti-CD20 therapy is active in the post-transplantation lymphoproliferative disorders. T-cell antibodies are under evaluation in a number of T-cell lymphoproliferative disorders. Targeted therapy has changed the natural history of a number of aggressive non-Hodgkin lymphomas. This review will describe the contributions of antibody therapies to the treatment of these diseases.
 ...
PMID:Antibody therapy in aggressive lymphomas. 1802 38

Rituximab is a monoclonal antibody that targets the uniquely expressed B-cell CD20 receptor. Although recently approved for treatment of follicular lymphomas, the intracellular events that occur when rituximab binds to CD20 are largely unknown. Quantitative proteomic analysis of B-cell lymphoma-derived cells exposed to rituximab was performed. Differentially expressed proteins belonged to functional groups involved in migration, adhesion, calcium-induced signaling, ubiquitination, and components of the phosphoinositol and NF-kappaB pathways. Our studies reveal the proteomic consequences of rituximab treatment and provide novel insights into the mechanism of action of the drug in susceptible B-cell lymphoproliferative disorders.
 ...
PMID:Quantitative proteomic analysis of follicular lymphoma cells in response to rituximab. 1901 92

CD19 and CD20 are B cell-specific antigens whose expression is heterogeneous when analyzed by flow cytometry (FCM). We determined the association between CD20 expression and clinical outcome in patients with diffuse large B-cell lymphoma (DLBCL). The mean fluorescence intensity of CD20 and CD19 was determined by FCM, and the cytoplasmic expression of CD20 was determined by immunohistochemistry (IHC) on 272 diagnostic DLBCL samples. Exon 5 of the MS4A1 gene coding for the extracellular component of the CD20 antigen was sequenced in 15 samples. A total of 43 of 272 (16%) samples had reduced CD20 expression by FCM; of these, 35 (13%) had bright CD19 expression. The latter had a markedly inferior survival when treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or rituximab-CHOP (R-CHOP; median survival of 1.2 and 3.0 years vs not reached for the others, P < .001 and P = .001), independent of the International Prognostic Index. A total of 41 of 43 samples with reduced CD20 expression by FCM had strong staining for CD20 by IHC. There were no mutations in exon 5 of the MS4A1 gene to explain the discrepancy between FCM and IHC. CD20 and CD19 expression by FCM should be determined on all biopsies of patients with DLBCL because reduced CD20 expression cannot be reliably detected by IHC.
 ...
PMID:Diffuse large B-cell lymphoma: reduced CD20 expression is associated with an inferior survival. 1902 41

Rituximab binds an epitope on the CD20 antigen, encompassed in exon 5 of the MS4A1 gene. We sequenced this region and correlated the presence of mutations with CD20 protein expression and response to R-CHOP in patients with diffuse large B-cell lymphoma: 264 diagnostic biopsies and 15 biopsies taken at the time of relapse were successfully sequenced. CD20 mutations involving the rituximab epitope were detected in only 1/264 (0.4%) and 1/15 (6%) of the biopsies taken at diagnosis and relapse, respectively. No polymorphic sequence variants were detected in this region. Three patients had malignant cells that were CD20 protein-positive at diagnosis but CD20-negative at relapse. Thus, CD20 mutations involving the rituximab epitope are rare in both de novo and relapsed diffuse large B-cell lymphoma, and do not represent a significant cause of R-CHOP resistance. CD20 protein-negative relapses occur after R-CHOP therapy but their clinical relevance is unknown.
 ...
PMID:CD20 mutations involving the rituximab epitope are rare in diffuse large B-cell lymphomas and are not a significant cause of R-CHOP failure. 1921 44


<< Previous 1 2 3 4 5 6 Next >>