Immunotherapy with monoclonal antibodies in metastatic melanoma

Dendritic nanoparticles for immune modulation: a potential next-generation nanocarrier for cancer immunotherapy

Immune activation, whether occurring from direct immune checkpoint blockade or indirectly as a result of chemotherapy, is an approach that has drastically impacted the way we treat cancer. Utilizing patients' own immune systems for anti-tumor efficacy has been translated to robust immunotherapies; however, clinically significant successes have been achieved in only a subset of patient populations. Dendrimers and dendritic polymers have recently emerged as a potential nanocarrier platform that significantly improves the therapeutic efficacy of current and next-generation cancer immunotherapies. In this paper, we highlight the recent progress in developing dendritic polymer-based therapeutics with immune-modulating properties. Specifically, dendrimers, dendrimer hybrids, and dendronized copolymers have demonstrated promising results and are currently in pre-clinical development. Despite their early stage of development, these nanocarriers hold immense potential to make profound impact on cancer immunotherapy and combination therapy. This overview provides insights into the potential impact of dendrimers and dendron-based polymers, offering a preview of their potential utilities for various aspects of cancer treatment.

Expression of complement regulator proteins in primary and metastatic malignant melanoma

The expression of complement regulatory antigens C3b/C4b receptor, (CD35) membrane cofactor protein (CD46), decay accelerating factor (CD55), and homologous restriction factor 20 (CD59) was determined immunohistochemically on ten primary malignant melanomas, 16 metastatic lesions, and ten melanocytic nevi. All of the melanocytic nevi and 9/10 primary melanomas showed both expression of CD46 and CD59. In one primary melanoma lacking CD46, expression of CD35 could be detected. In metastatic melanoma, 9/16 metastases were CD46+/CD59+, two were CD46-/CD59+, one CD46+/CD59-, and four CD46-/CD59-. Additionally, CD55 could be detected in two CD46+/CD59+ metastases, and CD35 in one. Expression or lack of complement regulatory antigens did not correlate with the expression of GD2, GD3, HMB-45 or S-100. In conclusion, some cases of metastatic melanoma show loss of normal expression of complement regulatory proteins. This might have implications on the immune response or the efficacy of immune therapy in malignant melanoma.

Bispecific antibodies for treatment of cancer in experimental animal models and man

Immunotherapy is a powerful anti-cancer treatment modality. However, despite numerous encouraging results obtained in pre-clinical studies, a definite breakthrough towards an established clinical treatment modality has as yet not occurred. Antibodies against tumor antigens have been shown to localise at the site of the tumor, but inadequate triggering of immune effector mechanisms have thwarted clinical efficacy thus far. Cellular immunotherapy has been hampered by limitations such as lack of specificity, down-regulation of major histocompatibility complex (MHC)-expression or Fas ligand up-regulation on tumor cells. This review focuses on the use of bispecific antibodies (BsAbs) for immunotherapy of cancer. Using BsAbs, it is possible to take advantage of the highly specific binding characteristics of antibodies and combine these with the powerful effector functions of cytotoxic immune effector cells. BsAbs share two different, monoclonal antibody-derived, antigen-recognizing moieties within one molecule. By dual binding, BsAbs reactive with a trigger molecule on an immune effector cell on the one hand and a surface antigen on a tumor target cell on the other are thus able to functionally focus the lytic activity of the immune effector cell towards the target cell. Over the last few years, the concept of BsAb-mediated tumor cell killing has been studied extensively both in preclinical models and in a number of phase I clinical trials. Promising pre-clinical results have been reported using tumor models in which diverse immune effector cell populations have been used. Despite this pre-clinical in vivo efficacy, the first clinical trials indicate that we are still not in a position to successfully treat human malignancies. This review discusses the production of BsAbs, the choice of trigger molecules in combination with potential effector cells and the preclinical models that have led to the current use of BsAbs in experimental clinical trials. It has become clear that appropriate immune cell activation and establishing a favourable effector-to-target cell ratio will have direct impact on the efficacy of the therapeutic approaches using BsAbs. New directions are discussed, i.e. finding appropriate dosage schemes by which immune effector cells become redirected without inducing hyporesponsiveness, defining possibilities for combining different immune effector cell populations and creating an in situ tumor environment that allows maximal tumoricidal activity

Common cancers--immunotherapy and multidisciplinary therapy: Parts III and IV

The refractoriness of many solid tumors to cytotoxic chemotherapy has led to the exploration of new therapeutic modalities, including immunotherapy. Immunotherapy does not have a direct cytotoxic effect on the cancer cell but is an attempt to promote rejection of the tumor by the host, chiefly through the cellular arm of the immune system. The clinical success with immunotherapy (primarily adoptive immunotherapy) among patients with unresectable malignant melanoma and cancer of the kidney has not been marked by the large numbers of patients responding but by occasional dramatic effectiveness of therapy for these cancers, which usually are refractory to chemotherapy. Long-lasting responses and even complete disappearance of all known metastases are possible for a small percentage of patients with melanoma or renal cell carcinoma who undergo immunotherapy. A reasonable approach for patients with good performance status (no symptoms or ambulatory with symptoms but not bedridden) is entrance to clinical trials, especially trials examining adoptive or active immunotherapy for melanoma or adoptive immunotherapy for renal cancer. The overall treatment of patients with cancer has changed. Primary-care physicians detect almost all cancers. The days when "taking it out" is the best we could offer a patient are over. As we learn more about the use of adjuvant or neoadjuvant chemotherapy and radiation therapy, it is likely one or both of these modalities will be incorporated into the treatment of additional solid tumors previously managed solely with surgical resection. Increasingly, additional therapy is being given for earlier-stage disease as we define how to maximize the potential for cure with minimal toxicity. Many new therapies are on the horizon, including the use of noncytotoxic treatments as an adjunct to a surgical procedure. Such therapies include the use of angiogenesis inhibitors, tumor vaccines, and immunotherapy. Now and in the future, patients will be best served when treated in an environment that can integrate medical, surgical, and radiation oncology actively.

Immunotherapy of malignant melanoma

Immunotherapy and biologic therapy of malignant melanoma are based on a sound scientific rationale and show promising preliminary results. As the nature of immune response to melanoma becomes further characterized, it is likely that more specific immune manipulations may be approached clinically. The fact that complete and partial remissions are induced in some patients with metastatic malignant melanoma by INF-alpha, IL-2, LAK cells, TIL cells, tumor vaccines, and the like clearly indicates a potential role for immunotherapy. As the overall response rates to these maneuvers are only in the range of 20%, more basic research is needed to understand more fully the immune mechanisms of tumor rejection. The combination of chemotherapy with biologic therapy has also provided promising leads. A major area waiting for development is the use of immunotherapy and biologic therapy as adjuvant treatment for the prevention of recurrence after surgical removal of high-risk Stage I/II and Stage III disease. The future of immunotherapy, either specific active immunization with appropriate vaccines or adoptive immunotherapy, must be based on well-defined molecules and antigenic systems, with appropriate enhancement based on the principles of immune reaction. Numerous strategies may be developed to enhance immune response, with resultant activation and proliferation of effector cells, including MHC- and non-MHC-restricted cytotoxic effector cells against tumor cells. The practice and principles of immunotherapy of human melanoma may be applied to other solid tumors that are resistant to chemotherapy and radiation therapy. Further experimentation in immunotherapy trials of melanoma may result in reliable and predictable clinical responses.

Polysialogangliosides expressed by amelanotic melanoma: a possible explanation for the poor response to anti-monosialoganglioside antibody 202 in a patient with melanoma

A 52-year-old Japanese woman developed numerous amelanotic metastatic melanomas on the skin and in various organs three years after a surgical operation for primary melanoma on the right axilla. The patient was treated with monosialoganglioside specific monoclonal antibody 202; however, no apparent clinical effects were observed. Ganglioside analysis of a metastatic tumor demonstrated that it expressed GM3, GM2, GD3, GD2, and polysialogangliosides. Since polysialogangliosides rarely appear in melanomas, their expression may explain the patient's poor response to MAb 202. The relationship between ganglioside composition and the effect of anti-ganglioside monoclonal antibody is discussed.

Expression of sialylparagloboside in a case of liposarcoma: aberrant glycosylation in tumors arising in adipose tissues

Gangliosides of liposarcoma, lipoma and lipids from omental tissues were analyzed. By immunostaining after thin layer chromatography, gangliosides of liposarcoma were identified as GM3, sialylparagloboside and GD3, whereas those of lipoma were GM3 and GD3, and those of fat in omental tissues were GM3, GD1a, GD3 and some unknown ones. Expression of sialylparagloboside is thought to be very rare.

The role of radiation therapy in the treatment of head and neck cutaneous melanoma

INTRODUCTION

This study was undertaken to elucidate the efficacy of external beam irradiation in the treatment of head and neck malignant melanoma, in comparison with the efficacy of surgical excision and the efficacy of surgical excision combined with external beam irradiation.

MATERIALS AND METHODS

A retrospective chart review of all patients seen at the Department of Radiation Oncology at the University of California at Los Angeles Medical Center with the diagnosis of head and neck melanoma from 1973 to 1992 was conducted. Using chi 2 analysis, survival rates were examined for patients treated with excision alone, irradiation alone, and both excision and irradiation.

RESULTS

Patients were treated with primary excision (96%), salvage excision for recurrent or residual disease (47%), primary irradiation (9%), post-surgical-planned irradiation (22%), adjuvant chemotherapy (45%), and adjuvant immunotherapy (36%). The overall survival rate for the entire group was 29%. For patients with recurrent or regional disease, survival rates were 37% for those treated with excision in combination with irradiation, 20% for those treated with irradiation alone, and 19% for those treated with excision. Whereas the differences among groups were not statistically significant, the biologic implication is that external beam irradiation is effective in controlling regional disease, since the tumors treated with irradiation alone or excision in combination with irradiation were larger and more aggressive than those treated with excision alone.

CONCLUSION

External beam irradiation is of benefit in treating patients with melanoma who are ineligible for salvage surgery or as an adjunctive modality in situations where the risk of recurrence is high.

Prognostic factors in metastatic malignant melanoma treated with combined radiation therapy and hyperthermia

From May 1981 to September 1991, 38 patients with metastatic malignant melanoma were treated with combined radiation therapy and hyperthermia to a total of 97 hyperthermia treatment fields. Prior treatments to these sites included surgery (31 patients, 76 fields), chemotherapy (18 patients, 54 fields), immunotherapy (14 patients, 42 fields) and radiation therapy (7 patients, 13 hyperthermia fields). Hyperthermia was given to fields located in the head and neck region, trunk and extremities in 30, 45 and 22 cases, respectively. Nodular-diffuse tumours were present in 86 fields while 11 fields were treated for microscopic residual tumour deposits. Concurrent radiation therapy was given in 180-400 cGy per fraction, 2-5 times per week for a mean total dose of 4098 cGy per field. Hyperthermia treatments were delivered using either microwave or ultrasound devices (286 and 48 treatments, respectively) with a mean (range) of 3.4 (1-14) hyperthermia treatments per field for a mean (range) of 43 (10-70) min per field. Patients (n = 34; 84 fields) were available for follow-up for a mean (range) of 14.6 (0.4-82.5) months. At 3 weeks post-treatment, 34 fields had complete, ongoing, or partial responses; 39 fields had no response; and there were no recurrences in the 11 fields treated for microscopic residual disease. Local control was maintained in 31% (26/84) fields with a mean follow-up of 14.6 months. At 36 months, five patients remained alive with complete control of their treated local disease. Statistical analyses revealed that patients with soft tissue metastases only, who were older at the time of hyperthermia, had a longer time between initial diagnosis and hyperthermia treatment, received a higher dose of radiation, had no previous chemotherapy, and had small tumour volumes, had a higher initial response. Multivariate analyses revealed that the three-covariate model including time interval between initial diagnosis and hyperthermia treatment, previous chemotherapy, and metastases to soft tissue only, best predicted response. The results of the investigation support the continued study of combined radiation therapy and hyperthermia treatments for selected patients with metastatic melanoma, and indicate that long-term survival can occasionally be obtained with this approach.

Monoclonal antibodies in cancer therapy

A review of the clinical trials of antibody based cancer therapies reveals that this approach can, in rare cases, induce complete remissions in individual patients with cancer. Since these trials have usually involved patients with large tumor masses, tumor cell inaccessibility is probably a major reason for the prevailing failures. Minimal residual disease, the stage when tumor cells are few and dispersed, should therefore be a more promising target for therapeutic antibodies. This hypothesis is supported by a prospective randomized trial on patients with resected Dukes C colorectal carcinoma that resulted in increased survival and prolonged recurrence-free intervals. Thus, in addition to strategies designed to produce more effective, human-derived reagents, efforts need to be concentrated on directing passive antibody therapy towards the appropriate target.