Molecular biotherapy最新文献

The National Biotherapy Study Group (NBSG) conducted a broad phase II trial using interleukin-2 (IL-2) by continuous infusion and alpha interferon (IFN) subcutaneously in 267 patients with a variety of advanced cancers, including 29 with breast cancer, 89 with renal cancer, and 69 with melanoma. IL-2 [18 million international units (MIU)/m2] was given by continuous infusion for 108 hours with 3 mu/m2 subcutaneous IFN every other day during the IL-2 infusion. The patients were treated for 1 week followed by a 2-week rest. After two cycles of treatment, patients were evaluated for response. Of the 237 patients evaluable for response, 20 (8%) had a complete or partial response and 128 (54%) were stable. Therefore, 62% of the evaluable patients were nonprogressive during the first 90 days of IL-2/IFN therapy. The objective response rate was 11% in melanoma, 7% in renal cancer, 14% in breast cancer, and 3% in patients with a variety of malignancies for an overall response rate of 7% in these patients with advanced cancer. The patients were treated on a general medical ward and tolerated treatment well with fatigue and fever being nearly universal. Dyspnea, pruritus, chills, and elevated creatinines were frequent but less common. This combination biotherapy regimen has minimal activity in a variety of advanced cancers and must be compared with the best existing chemotherapy for each cancer type in randomized, prospective trials.

Preclinical in vitro assessment of highly purified natural human interleukin-2 (IL-2) packed in egg lecithin liposomes was performed in short- and long-term T-cell cloning and propagation systems, and in experiments testing induction of lymphokine-activated killer (LAK) cells. Liposomal IL-2 (lip-IL-2) was essentially as active as free natural or recombinant IL-2 for cloning and culture of both helper and cytotoxic alloreactive T cells. However, lip-IL-2 was found to be markedly inferior to free natural or recombinant IL-2 for the induction of LAK cells from normal donors. Nevertheless, lip-IL-2 was able to maintain LAK cytotoxicity of populations preactivated with free IL-2. These results suggest that lip-IL-2 can interact with activated T cells and LAK cells in the same way as free IL-2, but that it is much less efficient at activating LAK-cell precursors.

The effect of murine recombinant interferon-gamma (IFN-gamma) on cell-mediated cytotoxicity against tumor cells in vitro and in vivo was investigated using a spontaneously developed, weakly immunogenic, syngeneic murine mammary adenocarcinoma, designated JC, as the target. Preincubation of JC tumor cells with IFN-gamma increased the susceptibility of lysis by both cytotoxic T lymphocytes and interleukin-2 (IL-2)-induced lymphokine-activated killer cells in an IFN-gamma dose-dependent manner. A direct injection of IFN-gamma (10,0000 U/d) daily for 5 consecutive days into the JC tumor nodule on the backs of BALB/c mice reduced the tumor growth in comparison with that of the control group. This antitumor activity was further enhanced by combination with a simultaneous intraperitoneal injection of IL-2 (300,000 IU/d) daily for 5 consecutive days. Phenotypic examination of tumor-infiltrating lymphocytes after injection of IFN-gamma plus IL-1 revealed an increased percentage of the cells expressing asialo GM1, L3T4, and IL-2 receptors. Additionally, an enhanced expression of major histocompatibility complex class I molecules on the JC tumor cells was detected. These results indicated that a direct injection of IFN-gamma into the tumor accompanied with the administration of IL-2, by enhancing cell-mediated immunity of the hosts and expression of major histocompatibility complex class I antigens on target cells, will be of potential clinical value.

Wy 18,251 (Tilomisole; Wyeth Laboratories, Philadelphia, PA, USA) is a benzimidazole that is structurally similar to the antihelminth levamisole that has recently been approved for the adjuvant treatment of colon cancer. In preclinical models, Tilomisole caused less agranulocytosis than levamisole, but retained immunomodulating capabilities. We examined the effects of Tilomisole administered to cancer patients in four different dose schedules: 60 mg/m2 orally (p.o.) weekly, and 60, 300, or 960 mg/m2 p.o. daily for 1 month. All patients were immunosuppressed when treatment was initiated as defined by standardized assays of phytohemagglutinin, concanavalin A, pokeweed mitogen, and mixed lymphocyte responses. Tilomisole was well tolerated with no significant side effects in 25 patients. There were no antitumor responses noted in this setting of metastatic cancer. There was no improvement in concanavalin A or pokeweed mitogen assays at any dose or schedule, but there was sustained improvement in mixed lymphocyte reaction and phytohemagglutinin assays at the 60 mg/m2 daily dose. This drug may have favorable biological response modifying effects in vivo and be a suitable alternative to levamisole in cancer treatment, especially if agranulocytosis is a significant problem associated with widespread use of levamisole.

The protein-bound polysaccharide of Coriolus versicolor QUEL (PS-K) has been found to express antioxidant activity as an "ion-radical scavenger" in diamine oxidation reactions. The mode of this expression was examined to determine whether the drug functioned as a simple radical scavenger or mimicked the action of superoxide dismutase (SOD). The latter was confirmed in both enzymatic and nonenzymatic superoxide anion radical (O2-.) producing systems in vitro. The SOD mimetic activity of PS-K was demonstrated by quantitative analysis of hydrogen peroxide as the end product of O2-., its formation being assisted catalytically by SOD or PS-K. Analysis by electron spin resonance also confirmed the SOD mimetic activity of PS-K in a xanthine-xanthine oxidase reaction. Relative SOD activity with PS-K was approximately 1/8,000 in a KO2-O2-.-producing system. The SOD mimetic activity of PS-K resisted treatment by 0.7N HCl, 0.7N NaOH, boiling for 30 minutes in a double water bath, and digestion by pronase. Fractionation according to differences in molecular mass caused no significant increase in relative SOD activity within a certain range of molecular mass, indicating that there is no definite molecule expressing SOD mimetic activity. Tumor-bearing rats and human patients with digestive tract cancer who suffered from oxidative stress were relieved by a single intraperitoneal administration of PS-K or a 1-day peroral prescription.

The antiviral effects of selected combinations between acemannan (ACE-M), a long-chained, polydispersed, beta-(1,4)-acetylated mannan, were tested in combination with azidothymidine (AZT) and acyclovir (ACY) in vitro. The rationale for such combinations was based on the antiviral and immunomodulatory properties exhibited by ACE-M. In addition, the observed antiviral effects of ACE-M against human immunodeficiency virus type 1 (HIV-1) and other enveloped viruses appear to be related to modification of the glycosylation of viral glycoproteins. Therefore, the inhibitory effect of ACE-M does not overlap with that of AZT or ACY. The studies presented herein show that ACE-M combined with suboptimal noncytotoxic concentrations of AZT or ACY act synergistically to inhibit the replication of HIV-1 and herpes simplex virus type 1 (HSV-1), respectively. The median effect method was not applicable for analysis because the test compounds show mutually nonexclusive drug effects. For a meaningful evaluation and interpretation of the effects of drug combinations, the biological significance of combinations must be considered, that is, the protective effect of the combination, the noncytotoxicity of the combination, the mechanism(s) of action of the individual compounds comprising the combination, and so forth. With respect to effects on U1 cells latently infected with HIV-1, treatment with combinations of AZT and ACE-M does not potentiate virus replication.

To determine the maximally tolerated dose of a ricin A chain-conjugated antimelanoma antibody (XomaZyme-Mel), 20 patients with metastatic melanoma were treated with escalating doses of the murine immunotoxin given as single intravenous infusion over 30 minutes. The starting dose was 0.6 mg/kg and was escalated in five groups to a maximum of 1.6 mg/kg. The maximally tolerated dose was 1.25 mg/kg as three of six patients treated at 1.6 mg/kg developed unacceptable toxicity. The dose-limiting toxicity consisted of profound fatigue, myalgias, and arthralgias. These occurred within 4 days and resolved in 7 to 10 days. Other non-dose-limiting toxicities encountered consisted of hypoalbuminemia, weight gain, peripheral edema, mild hypotension, and flu-like syndrome; the severity of these was also dose related. In addition, two allergic reactions occurred, one severe. There was one durable complete response of 12+ months' duration and one brief mixed response lasting 3 months. We conclude that the maximum tolerated single dose of XomaZyme-Mel is 1.25 mg/kg. Phase I studies evaluating 1.25 mg/kg given in multiple doses at 2- to 4-week intervals and phase II studies to determine the response rate of a single 1.25 mg/kg dose are warranted.

Forty-three dogs and cats with spontaneous tumors were treated with the immunostimulating polysaccharide acemannan by intraperitoneal and intralesional routes of administration. Tumors from 26 of these animals showed histopathological evidence of immunological attack as shown by marked necrosis or lymphocytic infiltration. Thirteen showed moderate to marked tumor necrosis or liquefaction. Twenty-one demonstrated lymphoid infiltration, and seven demonstrated encapsulation. Twelve animals showed obvious clinical improvement as assessed by tumor shrinkage, tumor necrosis, or prolonged survival; these included five of seven animals with fibrosarcomas. It is believed that acemannan exerts its antitumor activity through macrophage activation and the release of tumor necrosis factor, interleukin-1, and interferon.

Normal feline bone marrow-derived macrophages released maximum concentrations of interleukin-6, tumor necrosis factor, and interleukin-1 when stimulated with ImuVert (Cell Technology Inc, Boulder, CO, USA) at dosages of 1.0 microgram/ml, 5.0 micrograms/ml, and 10.0 micrograms/ml, respectively. When ImuVert was administered to healthy adult cats, significant elevations in rectal temperature and neutrophil counts were observed 10 and 24 hours after each treatment. Weekly treatment with ImuVert failed to prevent or reverse viremia in cats when initiated prior to or 6 weeks after inoculation with feline leukemia virus.

This review focuses on the use of gamma-interferon (gamma-IFN) in cancer therapy. Although clinical trials using gamma-IFN have yet to identify a treatment niche for this cytokine, these studies have led to a greater understanding of the pleiotropic effects of this molecule on the human immune response, as well as identification of the dose range required for optimal biologic response modification. Thus, continued efforts to clinically develop gamma-IFN are warranted.