The current status of monoclonal antibodies in the diagnosis and therapy of cancer

Side-Effects of Monoclonal Antibody Infusions for the Diagnosis and Treatment of Cancer

This literature review presents an inventory of the nature and incidence of side-effects that arise from the clinical application of monoclonal antibodies (MoAb) for the diagnosis and treatment of cancer. Most side-effects occurred during therapy. Toxic reactions, such as fever, sweating and chills, were more common than immunological skin reactions; they were observed predominantly in association with the elimination of circulating target cells. Dosage and rate of administration of the MoAb appeared to have little influence on the reactions, which disappeared quickly and did not necessitate discontinuation of treatment. Serum sickness, anaphylactic reactions and bronchospasms were not common; the patients reacted quickly to the indicated therapy. Prevention of the side-effects described here, especially during diagnostic applications, was such that they need not form a barrier to the clinical use of MoAb.

Immunoglobulin idiotype expression in reactive lymphoid tissues and B-cell lymphomas

In an investigation of the immunoglobulin idiotypic expression of non-tumour and neoplastic B lymphocytes in situ, fresh-frozen specimens of reactive tonsils, lymph nodes and B-cell malignant lymphomas (B-MLs) from Japanese patients were studied immunohistochemically with 39 different anti-idiotype antibodies. In reactive lymphoid tissues, while idiotype-bearing cells were largely distributed sparsely in follicles and perifollicular areas, some were heavily crowded in particular germinal centres (GCs), suggesting the presence of oligoclonal proliferations of B-cells in GCs. Forty-eight out of 100 B-MLs reacted with anti-idiotype antibodies. This proportion was significantly higher than those reported in Western cases (27-36%), indicating that Japanese B-MLs share public idiotypes much frequently than western cases. The idiotypes demonstrated in these lymphomas, in contrast to those not expressed in any B-ML, were found much commonly in non-tumour lymphocytes, suggesting that such public idiotypes as were common in B-MLs were frequently shared by normal B-lymphocytes.

Cytokines in cancer therapy

Cytokines, small biological response modifying proteins produced by hematopoietic and other cells, may one day play a significant role in the treatment of human cancer. This article presents an overview of the cytokines, including descriptions of their origins, mechanisms of action, and antitumor activities. Several classes of cytokines are discussed, including the interferons, the interleukins, and tumor necrosis factor. Several of these agents, either alone or in combination, are currently involved in clinical trials for the treatment of specific cancers. Th interaction of cytokines and monoclonal antibodies is also discussed.

A phase 1a clinical trial of LYM-1 monoclonal antibody serotherapy in patients with refractory B cell malignancies

Ten patients with refractory B cell lymphomas were treated with weekly intravenous infusions of escalating doses of murine monoclonal antibody (MoAb) LYM-1 over four weeks. LYM-1 is a recently developed IgG2a murine MoAb that recognizes a polymorphic HLA-Dr antigen on surfaces of normal and malignant B cells but does not bind to any other normal tissues. MoAb LYM-1 has several advantages for serotherapy, since the antigen it recognizes is not shed from the cell surface and does not modulate in response to MoAb therapy. Furthermore, in vitro studies have indicated significant anti-tumour activity against lymphoma cell lines. In the current trial, dose-dependent levels of free LYM-1 were detected in the serum of all patients, but penetration of extravascular tumour tissues was poor. No significant toxicity or human anti-mouse antibody responses were observed in any patient. Clinical responses were minor and appeared to correlate with the number of infiltrating T cells seen in the initial lymphoma specimens. LYM-1 appears to be well-tolerated and has demonstrated several potential advantages as a therapeutic agent in patients with lymphoma. The mechanism of anti-tumour effect and plans for further clinical studies are discussed.

Human leukemia cell binding and killing by anti-CD5 radioimmunotoxins

We have synthesized a reagent for antibody directed cell targeting composed of the monoclonal antibody (MoAb) T101 linked to the potent toxin ricin. The immunotoxin (IT) was subsequently radiolabeled by a cyclic anhydride procedure with 90Yttrium (90Y) to construct a radioimmunotoxin (RIT) that may have potential for cancer therapy. We evaluated the reagent for selectivity in binding and protein synthesis inhibition (PSI) assays. The RIT selectively bound antigen positive leukemia T-cell lines, with minimal binding to antigen negative control lines. The IT inhibited 87% or greater protein synthesis activity at 1 microgram/ml and exhibited an IC50 (the dose inhibiting 50% activity) of 0.18 +/- 0.08 microgram/ml in the presence of lactose. RIT and nonlabeled IT showed comparable degrees of PSI at 1 microgram/ml and 10 micrograms/ml, suggesting that labeling had little overall effect on the activity of the immunoconjugate. However, indirect evidence showed that the galactose binding site of ricin was inhibited 10-fold by its exposure to 90Y. Control RIT were minimally inhibitory. IT labeled with 131Iodine (131I) by an iodine monochloride technique also retained its capability to selectively inhibit protein synthesis. When RIT were tested for potency in a clonogenic assay against human leukemia T-cell lines, they inhibited 3.61 logs of tumor cell growth at 10 micrograms/ml. This did not represent an improvement over the log elimination with radiolabeled antibody alone, which showed 4.19 log elimination of tumor cells. Our observation that the 90Y-labeled RIT and labeled antibody can selectively eliminate about four logs of tumor cells in an in vitro clonogenic assay is unique. The ability of RIT to kill several logs of tumor cells in vitro renders RIT interesting anti-tumor reagents.

The non-Hodgkin's lymphomas: pathology, staging, treatment

The non-Hodgkin's lymphomas include a broad range of neoplasms derived from the T cells and B cells and their precursors in the lymphoid system. Although they are not among the most common cancers, the lymphomas have engendered a great deal of interest among researchers because of their interesting biology and responsiveness to therapy. The non-Hodgkin's lymphomas include at least ten major subtypes of diseases with different morphologic characteristics and clinical behavior. Based upon survival characteristics, it is convenient to divide the lymphomas into three broad categories, low grade, intermediate grade, and high grade. The low grade lymphomas usually arise in middle age or older individuals (median age, 55 years). They are derived from B cells and often have a follicular architectural pattern. They usually present with advanced stages of disease, often by virtue of bone marrow involvement. Nevertheless, patients are usually asymptomatic and may even have spontaneous regressions of disease. These lymphomas are responsive to a broad range of therapies including irradiation, single agent or multi-agent chemotherapy, or combined modality therapy. They are also affected by treatment with biologicals such as alpha interferon and monoclonal antibodies. Unfortunately, response to any of these therapies is often transient and relapse is common. The intermediate grade lymphomas include the common large cell lymphomas (follicular or diffuse) and diffuse mixed cell lymphoma. The lymphomas, together with the high grade immunoblastic lymphoma, are often grouped together for the development of management strategies. These lymphomas may be derived from B cells or T cells. They occur over a broader age range than the low grade lymphomas and they are much more aggressive in their natural behavior. Effective treatment programs have been developed for both limited and advanced clinical stages of disease. In limited disease, moderately intensive chemotherapy is often combined with involved field irradiation. In advanced stage disease, more aggressive combination chemotherapy programs are usually employed. From 40% to 80% of patients may be cured with these approaches, depending upon the initial extent of disease. Two types of high grade lymphoma-lymphoblastic and small noncleaved cell are particularly aggressive in their behavior. Lymphoblastic lymphoma is a T cell lymphoma that often arises in adolescent males and presents with a large mediastinal mass, marrow, and CNS involvement. It closely resembles acute lymphoblastic leukemia (ALL) and similarly intensive chemotherapy programs as are utilized in ALL may be successful in its management.(ABSTRACT TRUNCATED AT 400 WORDS)

Bioassays. Patents and literature

Bioassays, including immunoassays, enzyme assays, and assays using enzyme electrodes, and nucleic acid hybridization probes have been the subject of considerable industrial and academic research. New bioassay methods have applications in the medical, chemical, pharmaceutical, and food products industries. Recent US patents and scientific literature on a variety of new bioassay methods are surveyed. A description of these patents and a list of references are given.