ONCOLOGY Vol 16 No 3

This phase II study aimed to evaluate the tolerability and activity of the monoclonal anti-CD20 antibody rituximab (Rituxan) in patients with either untreated or relapsed biopsy-proven extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type, with measurable or evaluable disease.

At the 2000 Annual Meeting of the American Society of Hematology, we presented the benefits of rituximab (Rituxan) combined with CHOP (cyclophosphamide [Cytoxan, Neosar], doxorubicin HCl, vincristine [Oncovin], prednisone), known as R-CHOP, in comparison with CHOP alone for the treatment of elderly patients with diffuse large B-cell lymphoma (DLCL).

This phase II trial investigated the safety and efficacy of a combined-modality treatment with rituximab (Rituxan) and fludarabine (Fludara) in patients with fludarabine- and anthracycline-naive chronic lymphocytic lymphoma (CLL).

Rituximab (Rituxan) is a chimeric IgG1 anti-CD20 monoclonal antibody increasingly used in the treatment of non-Hodgkin’s lymphoma (NHL). Previous in vitro studies have suggested the role of antibody-dependent cellular cytotoxicity (ADCC) and FcgR-positive effector cells (natural killer and macrophage) in the antitumor effects of anti-CD20 antibodies, but the actual mechanism of rituximab action in vivo remains largely unknown. The FCGR3A gene coding for the FcgRIIIa receptor displays a functional dimorphism with either a phenylalanine (FCGR3A-158F) or a valine (FCGR3A-158V) at amino acid 158, with a higher affinity of human IgG1 and increased ADCC for the latter. The aim of this study was thus to determine the influence of this FCGR3A polymorphism on clinical and molecular responses to rituximab.

Rituximab (Rituxan), when combined with CHOP (cyclophosphamide [Cytoxan, Neosar], doxorubicin HCl, vincristine [Oncovin], prednisone) chemotherapy (R-CHOP) in the treatment of patients with CD20-positive diffuse large B-cell lymphoma (DLCL), significantly prolongs event-free and overall survival (GELA [Groupe d’Etude des Lymphomes de l’Adulte] LNH 98-5 study). Our objective was to estimate the cost-effectiveness of R-CHOP based on the evidence currently available.

Intravenous immunoglobulin (IVIG) is prepared from large pools of plasma from healthy donors and is widely used to treat autoimmune diseases, especially immune thrombocytopenic purpura (ITP). Human polyclonal antierythrocyte antibodies, such as anti-D, can also be effective at treating ITP in individuals expressing the appropriate antigen. The demand for IVIG and anti-D exceeds the supply, and the development of a recombinant product to replace these human-derived blood products would be highly desirable. We have hypothesized that monoclonal antibodies directed against red cells may be effective in inhibiting immune forms of thrombocytopenia.

The US Food and Drug Administration has approved Amgen’s pegfilgrastim (Neulasta) for use in decreasing the incidence of infection, as manifested by febrile neutropenia. The agent, administered in a single fixed dose per chemotherapy cycle, is indicated for patients with nonmyeloid malignancies who are receiving myelosuppressive chemotherapy associated with a significant incidence of febrile neutropenia.

Data from a phase II clinical study demonstrated that the investigational oral agent rubitecan (9-nitrocamptothecin, or 9NC) is active in both chronic myelomonocytic leukemia (CMML) and myelodysplastic syndromes (MDS). These data were presented at the 43rd annual meeting of the American Society of Hematology (ASH) in Orlando.

Prostate cancer has been the most common visceral malignancy in American men for the last decade. The estimated lifetime risk of the disease in the United States is 16.6% for white men and 18.1% for African-American men, with a lifetime risk of death of 3.5% and 4.3%, respectively.[1] Recently, the National Cancer Institute (NCI) reported that the overall cancer mortality rate decreased between 1990 and 1997, including a reduction of approximately 6% in prostate cancer mortality.[1] Furthermore, Tarone et al reported that the mortality rate for prostate cancer among white men in the United States declined to a level lower than that reported prior to the introduction of prostate-specific antigen (PSA)-based screening in 1987.[2]

Well-differentiated thyroid cancer is something of an anomaly in the field of oncology for two primary reasons. First, the team of physicians who manage the patient consists primarily of endocrinologists, endocrine surgeons, and nuclear medicine physicians instead of medical oncologists, surgical oncologists, and radiation oncologists. Second, there is an extremely high rate of cure with remarkable 10- and 20-year survival rates due to the indolent nature of the tumor, even in the setting of lymph node metastases.

According to studies presented at the 43rd annual meeting of the American Society of Hematology (ASH), tositumomab/iodine-131 tositumomab (Bexxar), an investigational radioimmunotherapy being evaluated for the treatment of low-grade or transformed low-grade non-Hodgkin’s lymphoma (NHL), produced durable, long-term responses when used alone or following chemotherapy. Multiple presentations suggested that tositumomab/iodine-131 tositumomab may be an important new treatment option for patients with relapsed or refractory NHL and, in particular, for patients whose prognosis is poor.

Previously untreated mantle cell lymphoma (MCL) is an uncommon disorder with a poor prognosis when treated with CHOP-like (cyclophosphamide [Cytoxan, Neosar], doxorubicin HCl, vincristine [Oncovin], prednisone) regimens. Typically the complete remission (CR) rate is 20% to 30%, median failure-free survival (FFS) is 10 to 16 months, and median overall survival (OS) is 3 years.

Front-line treatment for previously untreated follicular B-cell lymphoma with the iodine-131-labeled anti-CD20 antibody tositumomab (Bexxar) has been reported to result in a 97% response rate and a 74% complete response rate. Although the median duration of response has not yet been reached with a median follow-up of 2.7 years, concerns have been raised over the tolerability of salvage treatments upon relapse of disease. We have reviewed the clinical course of the 28 patients that have relapsed among the original group of 76 patients treated with tositumomab/iodine-131 tositumomab as front-line therapy.