Immunotherapy of patients with advanced cancer using tumor-infiltrating lymphocytes and recombinant interleukin-2: a pilot study

Clinical investigations using the adoptive transfer of lymphokine-activated killer (LAK) cells and recombinant interleukin-2 (rIL-2) to treat patients with advanced cancer have yielded encouraging results. We have thus sought ways to enhance the effectiveness of adoptive immunotherapy while minimizing its toxic side effects. Murine experiments have identified tumor-infiltrating lymphocytes (TIL) as killer cells more effective than LAK cells and less dependent on adjunctive systemically administered IL-2 to mediate antitumor effects. Accordingly, we performed a pilot protocol to investigate the feasibility and practicality of administering IL-2-expanded TIL to humans with metastatic cancers. Twelve patients, including six with melanoma, four with renal cell carcinoma, one with breast carcinoma, and one with colon carcinoma, were treated with varying doses and combinations of TIL (8.0 X 10(9) to 2.3 X 10(11) cells per patient), IL-2 (10,000 to 100,000 U/kg three times daily to dose-limiting toxicity), and cyclophosphamide (CPM) (up to 50 mg/kg). Two partial responses (PR) to therapy were observed: pulmonary and mediastinal masses regressed in a patient with melanoma, and a lymph node mass regressed in a patient with renal cell carcinoma. One additional patient with breast cancer experienced a partial regression of disease in lymph nodal and cutaneous sites with complete elimination of malignant cells from a pleural effusion, although cutaneous disease recurred at 4 weeks. The toxicities of therapy were similar to those ascribed to IL-2; no toxic effects were directly attributable to TIL infusions. In five of six melanoma patients, TIL demonstrated lytic activity specific for the autologous tumor target in short-term chromium-release assays, distinct from the nonspecific lytic activity characteristic of LAK cells. This study represents an initial attempt to identify and use lymphocyte subsets with enhanced tumoricidal capacity in the adoptive immunotherapy of human malignancies.     

Adoptive cellular therapy

We provide a current review of adoptive cellular therapy in the management of metastatic renal cell carcinoma. A comprehensive literature review of peer-reviewed articles on the development and use of adoptive cellular immunotherapy was performed. Renal cell carcinoma is a highly immunogenic tumor that has proven resistant to standard cytotoxic chemotherapy, but has shown reproducible response to immune-based therapy. In an effort to improve responses, a variety of adoptive cellular strategies have been devised and tested in the setting of metastatic disease. Among the techniques developed, the use of lymphokine-activated killer (LAK) cells, autolymphocyte therapy (ALT), and tumor-infiltrating lymphocytes (TIL) have been the best studied. While further trials are ongoing, thus far, these approaches have not consistently shown benefit in comparison to standard immune-based treatment with biologic response modifiers, most importantly, high-dose bolus interleukin-2 (IL-2). Future approaches, including the use of dendritic cells (DC) to facilitate the development of tumor vaccines, are encouraging. Advanced renal cell carcinoma continues to inspire research of promising new cellular immunotherapeutics. The experience with LAK, ALT, and TIL has greatly increased our understanding of tumor immunobiology, and has led to the ongoing development of new technology, including DC, vaccine, and antibody therapy.     

Specific active immunotherapy does not prolong survival in surgically treated patients with stage IIB malignant melanoma and may promote early recurrence

A prospective trial with concurrent controls was designed to assess the effects of specific active immunotherapy in patients receiving intermittent cytotoxic chemotherapy (DTIC + Vincristine) as an adjuvant to surgery in Stage IIB malignant melanoma. The treated group received monthly irradiated allogeneic melanoma cells and BCG, and the controls BCG only. Sixteen patients in the treatment arm had a median relapse-free interval of 5 months, compared to 8 months in 12 controls given chemotherapy and BCG, and because of this we felt that continuation of the study was unjustified on ethical grounds. Although all the controls who relapsed did so at distant sites, 7/11 patients given specific active immunotherapy relapsed initially within the lymphatic drainage area of the primary tumour. The median intervals from starting treatment to relapse at distant sites, and the median survival were identical in the 2 groups. We conclude that immunotherapy comprising irradiated allogenic melanoma cells as employed in this study does not prolong survival in surgically treated Stage IIB malignant melanoma and may even promote early, local relapse.     

Locoregional immuno(bio)therapy for liver metastases

Despite advances in locoregional chemotherapy, treatment of metastatic liver tumors remains a challenge. Since the liver is the largest organ of the reticuloendothelial system, locoregional immunotherapy would be a reasonable approach for the management of hepatic metastases. Indeed, various immunological approaches have been explored. Regional infusion of cytokines such as interleukin 2 (IL-2) or tumor necrosis factor-alpha (TNF-alpha) through the hepatic artery or the portal vein has been combined with chemotherapy and demonstrated to be better than chemotherapy alone. Locoregional adaptive immunotherapy (AIT) using lymphokine-activated killer (LAK) cells or tumor-infiltrating lymphocytes (TIL) has also been tried with rather disappointing responses. Addition of immunostimulants such as OK-432 to AIT increased clinical responses. Recently, several new approaches have emerged to improve the outcome of locoregional immunotherapy. Embolization of melanoma metastatic to the liver with a granulocyte-macrophage colony-stimulating factor (GM-CSF)/ethiodized oil emulsion resulted in control of liver metastases, as well as development of significant immune responses in remote extrahepatic metastases. A gene therapy designed to introduce foreign major histocompatibility complex (MHC) molecules in colorectal metastases has proven to be a safe and feasible approach. Larger scale clinical trials are mandatory to define the role of locoregional immunotherapy for metastatic tumors in the liver.     

Lysis of autologous melanoma cells by tumor-infiltrating lymphocytes: association with clinical response

Tumor-infiltrating lymphocytes (TILs) can be grown in vitro in medium containing interleukin-2 (IL-2). In clinical trials at the Surgery Branch of the National Cancer Institute, patients with metastatic malignant melanomas were treated with IL-2 plus the adoptive transfer of autologous TILs. At the time of treatment, TILs were assayed for in vitro lysis of fresh autologous and allogeneic melanoma cells and Daudi cells. Patients were evaluated for clinical response 4-8 weeks later. Lysis of autologous tumor cells by TILs was significantly higher for responding than for nonresponding patients. Tumor cells from responding and nonresponding patients were equally sensitive to lysis by allogeneic lymphokine-activated killer (LAK) cells. There was no difference between TILs from responding and nonresponding patients for lysis of LAK-sensitive Daudi cells, which was low in most cases and demonstrated that TIL lysis of autologous tumor cells was not due to LAK cells. The observed association of autologous tumor cell lysis by TILs with clinical response suggests that the development of culture methods to optimize lysis of autologous tumors may lead to increased response rates using this TIL treatment regimen.     

Natural killer and lymphokine-activated killer cell-mediated cytotoxicity in patients with oral cancer

Peripheral blood lymphocytes (PBL) from untreated and treated oral cancer patients, lymph node lymphocytes (LNL) from metastatic (met) and nonmetastatic (non-met) lymph nodes, and tumor infiltrating lymphocytes (TIL) were tested for natural killer (NK) and lymphokine activated killer (LAK) cell cytotoxicity using appropriate targets in a short-term chromium release assay. The results showed that while both NK and LAK functions of PBL from oral cancer patients were comparable to those of normal healthy donors, the NK activity of metastatic and nonmetastatic LNL and TIL was highly compromised. On the other hand, potent LAK activity could be generated from all three lymphoid populations. Individual patients showing low NK activity displayed good LAK cytotoxicity, indicating that endogenous cells with low NK potential have adequate ability to respond to interleukin 2 (IL-2). LAK activity tested on autologous tumour targets revealed that TIL were the best source of LAK cells. followed by PBL and LNL.     

Human autologous tumor-specific T cells in malignant melanoma

T cell lines and clones with autologous tumor-specific activity have been developed in malignant melanoma by stimulating peripheral blood lymphocytes (PBL), lymph node lymphocytes or tumor-infiltrating lymphocytes (TIL) with autologous melanoma cells in the presence of recombinant interleukin 2 (rIL2). T-cell lines and clones have been developed with specific cytotoxicity and/or proliferative responses for autologous melanoma targets but not for allogeneic melanoma tumor cells, autologous normal cells or natural killer (NK)-sensitive targets. The concentration of rIL2 is critical for the generation of autologous tumor-specific T-cell lines, with low rIL2 concentrations (up to 800 IU/ml) facilitating the growth of T-cell lines with tumor-specific activity. The T-cell receptor (TCR) and the CD3 antigen are involved in specific cytotoxicity and/or proliferative responses of these T-cell lines and clones. An oligoclonal pattern of -chain TCR gene rearrangements was observed on T-cell lines and clones with autologous tumor-specific cytotoxicity, suggesting that they are comprised of T cells that have undergone a clonal expansion in response to particular antigen. Autologous tumor-specific cytotoxic T cells are HLA-restricted and recognize on the melanoma tumor cells HLA Class I or possibly Class II antigens plus a tumor-specific determinant. TIL from patients with metastatic melanoma have unique characteristics in comparison with PBL and lymph node lymphocytes and they appear to contain substantial proportions of T cells that have been locally sensitized to autologous tumor cells. Single stimulation of TIL with autologous tumor cells in the presence of rIL2 is sufficient for the generation of T cell lines with autologous tumor-specific activity, whereas, multiple stimulation of PBL and lymph node lymphocytes was required to achieve the same purpose. TIL-derived T cell lines have been expanded in rIL2 in vitro by at least 1,500-fold without losing their activity. Approximately, 40% of the patients exhibited complete or partial responses to adoptive immunotherapy with melanoma TIL and rIL2.     

Vaccination: role in metastatic melanoma

Based on the poor impact on overall survival obtained by systemic chemotherapy in metastatic melanoma and the identification of many melanoma antigens recognized by T cells, in the last decade many efforts have been devoted to the development of active specific immunotherapy as a promising systemic treatment for this neoplastic disease. A number of Phase I–II clinical trials have been performed with different vaccination approaches that included whole tumor cells, antigen peptides, antigen-pulsed dendritic cells, recombinant viruses, plasmids or naked DNA, and heat-shock proteins. Despite some promising immunological and clinical results obtained in these studies, melanoma-specific vaccines have altogether failed to prove their efficacy in the few large Phase III randomized clinical trials performed. Nonetheless, the possibility of activating the human immune system to recognize and destroy tumor cells remains a challenging investigative field, considering that the new knowledge of the intricate cellular and molecular mechanisms that regulate the immune function and tumor–host interactions may allow the development of new clinically relevant melanoma vaccination strategies.     

Analysis of the proliferative and phenotypic properties of tumor infiltrating lymphocytes expanded in vitro in the course of the clinical trial of adoptive immunotherapy of metastatic melanoma

Adoptive immunotherapy with in vitro expanded tumor infiltrating lymphocytes (TIL) and recombinant interleukin-2 (rIL-2) is a recent option in the treatment of advanced melanoma resistant to conventional chemotherapy. In the course of a protocol of treatment of advanced melanoma with in vitro expanded TIL and rIL-2, we obtained 38 samples from 27 different patients. Lymphocytes derived were cultured in the presence of rIL-2 in vitro for a 4-6 week period and 23 resulted in proliferative cultures. Eighteen samples were infused in the course of the clinical trial. The median number of lymphocytes obtained was 18x10(9) (range 1-43x10(9)) cells. Phenotypic analysis showed that all samples contained a pure population of T cells. These data confirm that lymphocytes can be expanded from advanced metastatic sites, have peculiar characteristics and are suitable to be infused in vivo.     

Dendritic cell vaccination as a treatment modality for melanoma

As melanoma is an immunogenic tumor, immunotherapy has been investigated as a possible treatment modality for melanoma patients at high risk of relapse and those with metastatic disease. In the past decade progress has been made, ranging from rather nonspecific stimulations of the immune system with IL-2 and IFN-α to more specific approaches based on vaccination with tumor antigens. Owing to their unique features, dendritic cells (DCs) represent an important tool for tumor antigen-specific immunotherapy. However, clinical vaccination trials with DCs showed sobering results with respect to objective responses and improvement of overall survival. In this review, principles and methods of DC-based vaccination are presented. Mechanisms impairing clinically successful vaccination strategies are described. Finally, we will discuss perspectives for future developments of DC-based vaccines that might lead melanoma treatment to a new era.     

Vaccination: role in metastatic melanoma

Based on the poor impact on overall survival obtained by systemic chemotherapy in metastatic melanoma and the identification of many melanoma antigens recognized by T cells, in the last decade many efforts have been devoted to the development of active specific immunotherapy as a promising systemic treatment for this neoplastic disease. A number of Phase I-II clinical trials have been performed with different vaccination approaches that included whole tumor cells, antigen peptides, antigen-pulsed dendritic cells, recombinant viruses, plasmids or naked DNA, and heat-shock proteins. Despite some promising immunological and clinical results obtained in these studies, melanoma-specific vaccines have altogether failed to prove their efficacy in the few large Phase III randomized clinical trials performed. Nonetheless, the possibility of activating the human immune system to recognize and destroy tumor cells remains a challenging investigative field, considering that the new knowledge of the intricate cellular and molecular mechanisms that regulate the immune function and tumor-host interactions may allow the development of new clinically relevant melanoma vaccination strategies.     

Adjuvant immunotherapy of malignant melanoma.

A vaccine made of irradiated Vibrio cholerae neuroaminidase (VCN) treated autochthonous tumor cells plus BCG was utilized in combination with surgery or with chemotherapy for Stage II and Stage III malignant melanoma, respectively. A few patients with Stage I melanoma were treated with surgery and BCG. Most of the studies were carried out on a prospective, randomized protocol. When the results with conventional therapy were compared with the results of conventional therapy plus immunotherapy, no beneficial effects of the immunotherapy were seen. Stratification insured comparability in both immunotherapy and nonimmunotherapy groups. We conclude that VCN treated tumor cells plus BCG, when administered according to the protocol utilized here, offer patients with malignant melanoma no substantial benefit when compared with conventional therapy.     

Tumor‐infiltrating lymphocytes for the treatment of metastatic cancer

Over the past few years melanoma incidence has been rising steadily, resulting in an increase in melanoma related mortality. Until recently, therapeutic options for metastatic melanoma were scarce. Chemotherapy and, in some countries, IL‐2 were the only registered treatment modalities. In the last five years, treatment with immunotherapy (anti CTLA‐4, anti PD‐1, or the combination of these antibodies) has shown very promising results and was able to improve survival in patients with metastatic melanoma. Adoptive cell therapy using tumor‐infiltrating lymphocytes is yet another, but highly promising, immunotherapeutic strategy for patients with metastatic melanoma. This review will discuss the development of TIL as a treatment option for melanoma, its mode of action and simplification over time, and the possibilities to expand this therapy to other types of cancer. Also, the future directions of TIL based therapies will be highlighted.     

Management of recurrent melanoma of the extremity.

Two forms of therapy employed for treatment of patients with recurrent melanoma limited to the extremity, and carried out during different intervals of time, are presented. Perfusion of the involved extremity with phenylalanine mustard has resulted in a 5-year survival rate of 28% of 43 patients. A second group of 25 patients has been treated by a four-stage immunotherapy program consisting of sensitization with intradermal BCG, followed in 6 weeks by intra tumor injection of BCG. A third stage involved the activation of the patients's lymphocytes, after removal by a blood cell separator, incubated in vitro with irradiated neuraminidase-treated melanoma cells and reintroduced into the patient either by subcutaneous or intratumor injection. The fourth stage of immunotherapy involves injection of an inoculum of irradiated neuraminidase-treated autochothonous tumor cells plus BCG injected intratumorally or subcutaneously. Sixteen of 24 patients receiving immunotherapy treatment program have experienced arrest of their disease lasting from 5 to 42 months.     

Active immunotherapy as an adjunct to chemotherapy in the treatment of disseminated malignant melanoma: a pilot study.

In patients with disseminated malignant melanoma an optimal method of immunization with irradiated tumour cells was developed by reference to an in vitro assay for circulating specific serum inhibitors of cell mediated cytotoxicity. This immunization protocol consisted of the intradermal inoculation of 2 times 10(7) irradiated allogeneic melanoma cells admixed with 50 mug of percutaneous BCG. This method of immunization induced a significant but transient fall in the specific inhibitory effects of the sera on tumour directed cytotoxic activity of the patients' lymphocytes. In a pilot group of 30 patients with disseminated malignant melanoma being treated with chemotherapy (DTIC and vincristine) the immunotherapy was given midway between courses of the cytotoxic drugs. There was a correlation between the effects on circulating inhibitor and clinical outcome. The number of objective regressions occurring in this small pilot group was surprisingly high (17/30) and these clinical effects, although obtained in a series without concurrent controls, are presented for discussion. We suggest that the approach illustrated by this study, employing in vitro assays of tumour directed immune responses, may provide a suitable rational basis for the use of active immunotherapy as an adjunct to chemotherapy in the treatment of malignant disease.     

Immunogenicity of a polyvalent melanoma antigen vaccine in humans

Fifty-five patients with Stage II (36 patients) or Stage III (19 patients) malignant melanoma confirmed histologically received adjuvant immunotherapy with a polyvalent melanoma antigen vaccine to evaluate toxicity and immunogenicity. There was no toxicity. Antibody and/or cellular immune responses to melanoma were induced more frequently in Stage II (36 patients [69%]) than Stage III (19 patients [53%]) disease. The ability of different immunization schedules, alum, or pretreatment with low-dose cyclophosphamide to potentiate immunogenicity was compared after 2 months of immunization. Immunization biweekly with a fixed intermediate dose of vaccine was more immunogenic than immunization weekly with escalating vaccine doses. Alum increased the intensity of cellular responses slightly, whereas pretreatment with cyclophosphamide augmented both the incidence and intensity of cellular immune responses slightly. However, these changes did not reach statistical significance. There was a reciprocal relationship between the induction of humoral and cellular immune responses. These results show that (1) active immunotherapy with a polyvalent melanoma vaccine is safe in patients with minimal disease, (2) the vaccine augments immunity to melanoma in many, but not all, patients, and (3) several immunization strategies failed to potentiate immunogenicity significantly.     

Lymphokine-activated killer-cell function of lymphocytes from peripheral blood, regional lymph nodes and tumor tissues of patients with oral cancer

Lymphokine-activated killer (LAK) cells, generated from peripheral blood lymphocytes (PBL) from patients with oral cancer or oral leukoplakia and from healthy donors showed comparable lysis of 6 target tumor cell lines, including 3 derived from head and neck and oral cancers. The tumor burden of the host did not appear to influence the systemic LAK activity. LAK activity of lymphocytes infiltrating the tumor tissues (TIL) was also comparable to that of the PBL. Both TIL and PBL showed a parallel increase in proportion of HNK-I+ and CD-25+ cells upon activation with IL-2. The lymph-node lymphocytes (LNL) from metastatic (met) and non-metastatic (non-met) draining lymph nodes, however, showed reduced LAK activity and an increase in CD8+ cells, in addition to CD25+ and HNK-I+ cells, when cultured with IL-2. When IL-2-activated LNL were co-cultured with autologous PBL during IL-2 activation of the latter, a strong suppressive effect was exerted by LNL. In contrast, IL-2-activated PBL did not suppress autologous LAK generation in spite of an increase in CD8+ cells seen after activation with IL-2. Frequency distribution of LAK precursors was significantly lower in LNL than in PBL from oral cancer patients. LAK precursor frequency in TIL was comparable to that of PBL. The results show that, in oral cancer, regional lymph nodes may not have adequate IL-2-inducible cytotoxic potential, due to a reduced number of LAK progenitors and possible activation of suppressor cells. Alternatively, TIL can be a potential source for LAK cell function.     

Simultaneous generation of CD8+ and CD4+ melanoma-reactive T cells by retroviral-mediated transfer of a single T-cell receptor

Adoptive immunotherapy of cancer requires the generation of large numbers of tumor antigen-reactive T cells for transfer into cancer patients. Genes encoding tumor antigen-specific T-cell receptors can be introduced into primary human T cells by retroviral mediated gene transfer as a potential method of providing any patient with a source of autologous tumor-reactive T cells. A T-cell receptor-specific for a class I MHC (HLA-A2)-restricted epitope of the melanoma antigen tyrosinase was isolated from a CD4(+) tumor-infiltrating lymphocyte (TIL 1383I) and introduced into normal human peripheral blood lymphocytes by retroviral transduction. T-cell receptor-transduced T cells secreted various cytokines when cocultured with tyrosinase peptide-loaded antigen-presenting cells as well as melanoma cells in an HLA-A2-restricted manner, and could also lyse target cells. Furthermore, T-cell clones isolated from these cultures showed both CD8(+) and CD4(+) transduced T cells could recognize HLA-A2(+) melanoma cells, giving us the possibility of engineering class I MHC-restricted effector and T helper cells against melanoma. The ability to confer class I MHC-restricted tumor cell recognition to CD4(+) T cells makes the TIL 1383I TCR an attractive candidate for T-cell receptor gene transfer-based immunotherapy.     

Tumor-Infiltrating Lymphocytes in Melanoma

Adoptive cell therapy using tumor-infiltrating lymphocytes (TIL) is arguably the most effective treatment for patients with metastatic melanoma. With higher response rates than ipilimumab or IL-2, and longer durations of response than vemurafenib, TIL therapy carries the potential to transform current outcomes in melanoma, while also defining the way cell-based immunotherapy gets incorporated into mainstream cancer treatment. This paper will review the current state of TIL therapy in melanoma, the strategies to improve its efficacy, the current obstacles, and future directions to expand the availability of TIL to the general patient population.     

Gamma-interferon enhances the cytotoxic activity of interleukin-2-induced peripheral blood lymphocyte (LAK) cells, tumor infiltrating lymphocytes (TIL), and effusion associated lymphocytes.

The effect of gamma-interferon (IFN-gamma) on the induction of interleukin-2 (IL-2) activated killer cell activity was studied: (I) in peripheral blood lymphocytes (LAK cells) from cancer patients and healthy donors, (II) in lymphocytes infiltrating solid tumors (TIL) from melanoma and breast cancer patients, and (III) in pleural effusion associated lymphocytes (EAL) from patients with lung adenocarcinoma. The coculture of LAK, TIL and pleural effusion mononuclear cells (MNC) with several doses of IFN-gamma (10, 50, 250, and 1250 U/ml) and a low dose of IL-2 (10 U/ml) for 5 days resulted in a synergistic effect on the cytotoxicity of these cells against several tumor cell lines. Furthermore there was a potentiation in the proliferation of MNC after a 5-day culture. The induction of lymphocyte cytotoxicity by a combination of IFN-gamma with low doses of IL-2 may be helpful in designing more effective cancer immunotherapeutic protocols with LAK, TIL or EAL.