Phase I study of high-dose continuous-infusion recombinant interleukin-2 and autologous lymphokine-activated killer cells in patients with metastatic or unresectable malignant melanoma and renal cell carcinoma

Continuous infusion interleukin-2 and famotidine in metastatic kidney cancer

Infusional interleukin-2 (IL-2) is able to elicit lymphokine-activated killer cell (LAK) cytotoxicity against kidney cancer in vitro and in vivo. Famotidine may be able to augment LAK cytotoxicity against neoplastic cells. Fifteen (15) patients were treated with continuous-infusion IL-2 (9-18 MIU/m2/24 hours) for 72 hours and famotidine 20 mg intravenously twice per day. Cycles were repeated every 3 weeks. These patients had a median age of 60 years (range, 29-72), had a median performance status of 1 (range, 0-1), and had metastatic sites, including lung, bone, lymph node, and liver. The most common toxicities of this regimen were hypophosphatemia, fever, nausea/emesis, rigors, elevated creatinine, and hypomagnesemia. One (1) complete and 6 partial responses have been seen (47% response rate). The median duration of response is 9 months. The median survival for all patients is 20 months. Five (5) patients are alive at a median of 36+ months. This combination of infusional IL-2 with famotidine is active in metastatic kidney cancer.

Continuous infusion interleukin-2 and intravenous famotidine in metastatic melanoma

Lymphokine-activated killer cell (LAK) cytotoxicity against tumor cells is induced by the use of high-dose infusional interleukin-2 (IL-2). LAK cytotoxicity against neoplastic cells may be augmented by famotidine. Twelve (12) patients have been treated with continuous infusion IL-2 (18 MIU/m2/24 hours) for 72 hours and famotidine 20 mg IVPB twice per day. Cycles were repeated every 3 weeks. These patients were of median age--67 years (range, 25-79), had a median performance status of 1 (range, 0-1), and had metastatic sites, including lung, lymph node, subcutaneous/soft tissue, and liver. The most common toxicities of this regimen were fever, rigors, nausea/emesis, hypophosphatemia, and hypomagnesemia. Three (3) partial responses have been seen (25% response rate). One (1) of these responders has undergone complete surgical resection and is disease-free at 15+ months. Four (4) patients are alive at a median of > 25 months. The median survival for all patients is 13 months. This combination of infusional IL-2 with famotidine is active in metastatic melanoma.

Continuous Infusion Interleukin-2 and Antihistamines in Metastatic Kidney Cancer

A prior randomized trial suggested a possible survival advantage favoring the combination of histamine and subcutaneous interleukin-2 (IL-2), compared to IL-2 alone in patients with metastatic melanoma. It has been postulated previously that antihistamines may, therefore, actually be antagonistic to IL-2 and thus interfere with its antitumor activity. We have previously shown no such antagonistic effect in patients with melanoma receiving IL-2 and antihistamines when reviewing the known literature. We sought to determine whether there was any negative effect of the combination in patients with metastatic kidney cancer. A PubMed literature search between 1985 and 2005 was done. High-dose continuous (or constant) infusion (CIV) interleukin-2 was used as the reference therapy because of the relatively constant IL-2 levels generated by this approach. Studies in which cimetidine, ranitidine, or famotidine were regularly scheduled and administered concurrently with IL-2 were included. Thirteen studies were identified. A total of 47 patients responded to therapy. Total response rate = 22%; 95%; Confidence Interval: 17%-28%. Eleven complete responses were noted. Complete response rate = 5%; 95% Confidence Interval: 3%-9%. These response rates are consistent with previously noted IL-2 response rates. In this study of CIV IL-2 and antihistamines, this combination appears to be active in metastatic kidney cancer. There appears to be no negative effect of antihistamine on the CIV IL-2 response rate in this disease.

Continuous Infusion Interleukin-2 and Antihistamines in Melanoma: A Retrospective Review Showing Activity of This Combination

A recent randomized trial suggests that there may be an advantage in terms of survival with the combination of histamine and subcutaneous interleukin-2 (IL-2), compared to IL-2 alone. It has been postulated, then, that antihistamines may actually be antagonistic to IL-2 and, therefore, interfere with its antitumor activity. Because antihistamines such as cimetidine and ranitidine are commonly used as prophylaxis against gastrointestinal toxicity commonly seen with IL-2, and, because antihistamines may increase natural killer cell activity, it is reasonable to examine the response rate for this combination. An OVID Medline literature search between 1985 and 2003 was done. Continuous infusion (CIV) interleukin- 2 was used as the reference therapy because of the relatively constant IL-2 levels generated by this approach. Included studies were those in which either cimetidine, ranitidine, or famotidine were regularly scheduled and administered concurrently with IL-2, typically for gastrointestinal ulcer prophylaxis. Six (6) studies were identified. A total of 21 patients responded to therapy. Total response rate was 11%, with a 95% Confidence Interval: 7-17%. Four (4) complete responses were noted. Complete response rate was 2%, with a 95% Confidence Interval: 1-6%. These response rates are consistent with previously noted IL-2 response rates. In this retrospective review of CIV IL-2 and antihistamines, this combination appears to be active in melanoma. There appears to be no deleterious effect of routine antihistamine on the CIV IL-2 response rate.

Gene therapy for neurologic disease: benchtop discoveries to bedside applications. 1. The bench

The overall goal of this review is to provide the pediatric neurologist with a theoretical foundation in gene therapy. Gene therapy became feasible in the early 1970s and the first transfer of a foreign gene into humans was approved by the NIH in 1989. Adenovirus, adeno-associated virus, herpes-simplex virus, retroviruses, and other vectors have been used to efficiently transduce genes into cells in vitro and in vivo. We discuss laboratory experiments that have provided a strong scientific rationale for implementing human clinical trials of gene therapy for neurologic malignancy. The development of viral and nonviral vectors that mediate efficient gene insertion into human cells has created the prospect of using gene therapy for cancer or brain disease. The NIH has approved more than 100 gene therapy protocols since 1989. However, the field will require more research on gene delivery systems before gene therapy becomes an established therapeutic strategy for an array of central nervous system diseases.

Generation of chimeric bispecific G250/anti-CD3 monoclonal antibody, a tool to combat renal cell carcinoma

The monoclonal antibody (MAb) G250 binds to a tumour-associated antigen, expressed in renal cell carcinoma (RCC), which has been demonstrated to be a suitable target for antibody-mediated immunotherapy. A bispecific antibody having both G250 and anti-CD3 specificity can cross-link G250 antigen-expressing RCC target cells with T cells and can mediate lysis of such targets. Therapy studies with murine antibodies are limited by immune responses to the antibodies injected (HAMA response), which can be decreased by using chimeric antibodies. We generated a chimeric bispecific G250/anti CD3 MAb by transfecting chimeric genes of heavy and light chains for both the G250 MAb and the anti-CD3 MAb into a myeloma cell line. Cytotoxicity assays revealed that the chimeric bispecific MAb was capable of mediating lysis of RCC cell lines by cloned human CD8+T cells or by IL-2-stimulated peripheral blood lymphocytes (PBLs). Lysis mediated by the MAb was specific for target cells that expressed the G250 antigen and was effective at concentrations as low as 0.01 microgram ml-1. The chimeric bispecific G250/anti-CD3 MAb produced may be an effective adjuvant to the currently used IL-2-based therapy of advanced renal cell arcinoma.

Medical treatment of advanced renal cell carcinoma: present options and future directions

The treatment of patients with metastatic renal cell carcinoma (MRCC) continues to be disappointing. A large number of hormones, chemotherapeutic agents and combinations have been tested with poor and non-reproducible results. Among the immunological treatments investigated in MRCC, the best results have been claimed with interferons (IFNs) and interleukin-2 (IL-2) and, although no randomized studies have shown higher activity than cytotoxic drugs, hormones or even no treatment, many oncologists feel it justified to consider these biologic agents the treatment of choice for this disease. Of patients treated with alpha-IFN, 15-20% achieve an objective remission and 3-5% achieve a long-lasting complete response. No substantial increase of the therapeutic activity of alpha-IFN was produced by combination with chemotherapeutic agents and gamma-IFN or tumour necrosis factor. High doses of IL-2 with or without lymphokine-activated killer cells led to successful results in about 20-30% of patients with 5-10% complete responses. More recently, less toxic regimens with lower doses of IL-2 alone or combined with alpha-IFN produce similar response rates. Many studies have clarified the importance of prognostic factors in patient selection for response and survival during treatments with IFNs and IL-2. Good performance status, a long interval from diagnosis to treatment, and only one site of disease seem to be the most important predictors for survival. Both IFNs and IL-2 appear to possess encouraging antitumour activity in patients with favourable prognostic factors, but further studies are needed to identify the treatment of choice, the optimal dose regimen and route of administration in this subgroup of patients. Patients with poor prognosis should be encouraged to enter controlled studies aimed to evaluate investigational drugs and new therapeutic methods.

[Immunotherapy of malignant melanoma. New prospects]

Malignant melanoma is an immunogenic tumor which can induce host humoral and cellular responses, and is a good model for development of anti-cancer immunotherapy. During the last decade systemically-administrated interferon and interleukin-2 have been used. Advances in immunology and molecular biology could allow a more specific and active immunotherapy. Perspectives include chemo-immunotherapy, monoclonal antibodies alone or in combination with cytotoxic agents, adoptive immunotherapy with tumor-infiltrating lymphocytes (TIL), gene therapy designed to increase tumor immunogenicity, and active immunotherapy with vaccines.

Clinical significance of autologous tumor killing (ATK) activity and its induction therapy in human cancer

The activity of blood lymphocytes to kill autologous freshly isolated tumor cells tested at the time of surgery predicts a favorable clinical course in patients who have primary localized solid tumor and receive curative operation. The strong correlation of autologous tumor killing (ATK) activity with disease-free interval and total survival indicates that ATK activity is a meaningful prognostic indicator and provides evidence for immunological control of tumor growth and metastasis. Although there is no direct evidence that ATK lymphocytes play a critical role in regression of tumor and prevention of tumor regrowth, the lack of ATK activity in patients who relapsed and died may not result from other factors related to their poor performance status, immune functions and tumor characteristics. Clinical trials with ATK induction therapy resulted in an improvement of the clinical outcome in patients who naturally have no such potential. The data indicate that the presence of both natural and induced ATK activity is strongly associated with long-term survival. In addition, adoptive transfer of BRM-induced ATK effector cells resulted in prolongation of survival time even in patients with documented metastatic tumors. Thus, considerable emphasis should be placed on a strategy that induces ATK activity in vivo. Such an approach may provide a new focus for cancer immunotherapy.

Platinum drug delivery and radiation for locally advanced prostate cancer

Combined therapies of cisplatin and radiation have resulted in clinical reports of apparent efficacious control of locoregional cancer and enhanced survival. Mechanisms of interaction between platinum and radiation that may explain these clinical observations all have in common the prediction that higher concentrations of platinum in all tumor cells close in time to irradiation should lead to greater potentiation of radiation-induced killing of those cells. Cisplatin is thus viewed as providing some radiation-equivalent, or a radiation dose-effect factor, for sterilization of tumors. One disease site that has not been well investigated for response to cisplatin plus radiation therapy, but that could benefit from it, is locally advanced prostate cancer. A body of literature now supports the view that local control of stage C (T3, N0, M0) prostate cancer is correlated with disease-free survival. This correlation makes prostate cancer a candidate for potentially achieving improved cure rates following local tumor sterilization by combining cisplatin with radiation therapy. The need and approaches to optimize delivery of cisplatin within tumor tissue is explored. Increasing cisplatin concentration to all the cells of a tumor, i.e., homogeneously delivering systemic high-dose cisplatin, should benefit the efficacious response otherwise expected for cisplatin combined with radiation. Strategies to increase the homogeneity of cisplatin delivery to a tumor are considered to be those that increase perfusion to that tumor. Vasoactive agents used in anticancer protocols are especially considered for their potential value in serving to increase tumor perfusion. These protocol-inclusive agents include certain cytokines and L-arginine antagonists, and should be better managed and accepted in practice compared to other vasoactive agents that need to be developed as specific additives to protocol designs.

Biological significance of autologous tumor-killing activity and its induction therapy

The overall results presented in this review demonstrate that positive ATK activity at the time of surgery predicts a favorable clinical course in patients who have primary localized solid tumor and receive curative operation. The strong correlation of ATK activity with disease-free interval and total survival (a) indicates that ATK activity is a meaningful prognostic indicator and (b) provides evidence for immunological control of tumor growth and metastasis. According to these data, it is unlikely that cancer patients who remain tumor-free after 5 years of follow-up will develop recurrence or die from the disease. Although there is no direct evidence that ATK effector cells play a critical role in regression of tumor and prevention of tumor regrowth, the lack of ATK activity in patients who relapsed and died after surgery may not result from factors related to their poor performance status since no differences have been observed in background factors between ATK-positive and-negative groups. The prognostic value of ATK activity in patients with documented metastatic tumors has not been established yet. In this respect, however, the induction of ATK activity by BRM has positively correlated with prolonged survival time, while such a correlation is not observed with other parameters such as NK cells or LAK cell activity.

Based on the possible biological significance of ATK activity, clinical trials have been conducted to determine whether the induction of ATK activity before surgery by administration of BRM could improve the clinical outcome in patients who naturally have no such potential. The preliminary data indicate that the presence of both natural and induced ATK activity is strongly associated with longterm survival. Thus, considerable emphasis should be placed on a strategy that induces ATK activity in vivo. Such an approach may provide a new focus for cancer immunotherapy.

Interleukin 2 therapy: current role in surgical oncological practice

The use of recombinant interleukin 2 (rIL-2) in clinical practice has opened up new and beneficial avenues in the treatment of certain malignant diseases. Although rIL-2 can stimulate a range of host antitumour defence mechanisms, only 30-40 per cent of patients who are treated will respond to such therapy as assessed by a reduction in tumour volume. The effect of rIL-2-based treatment schedules on delaying progression of disease and on overall survival in comparison with standard current treatments and chemotherapeutic regimens is not clear. Randomized clinical trials are required to evaluate precisely the role of rIL-2 in various therapeutic combinations and to ascertain the optimum therapeutic regimens for individual tumour types. Studies currently under way should provide more insight into the possible beneficial effects of immunotherapy with rIL-2. More basic research is required to ascertain how rIL-2 may produce its antitumour effects and why the therapeutic results obtained in humans have been so selective and less beneficial than those in experimental animals.

Development and validation of a bioassay for interleukin-2

A reliable and precise method for the determination of IL-2 activity, based on stimulation of CTLL cell proliferation, was developed. Cells were incubated with different concentrations of IL-2 for 24 h in microtiter plates. The stimulatory effect was measured on a plate-reading spectrophotometer by reading the optical density of formazan, which is produced by viable cells from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The bioassay was designed as a four-dose parallel line test, fulfilling pharmacopoeial requirements for assay validity, and the inter-assay relative standard deviation (RSD) for a group of four experiments was 2.6%. The International Standard for human IL-2 and the Reference Reagent for Recombinant DNA-derived IL-2 were employed for potency determinations. The method was found suitable for potency assessments of pharmaceutical formulations of IL-2.

Chemo-immunotherapy in patients with metastatic melanoma using sequential treatment with dacarbazine and recombinant human interleukin-2: evaluation of hematologic and immunologic parameters and correlation with clinical response

We have treated 18 patients with metastatic malignant melanoma (MM) with high-dose IL-2 administered by continuous iv infusion in combination with dacarbazine (DTIC), and correlated the clinical response with various hematologic and immunologic parameters. Two regimens differing in the sequence of treatment were employed, and 1-6 treatment cycles were given, depending on patient response. Two patients had a complete response (CR, 46+m, 14m), two patients a partial response (PR, 16m,6m), one a minimal response and four had a stable disease lasting 2-7 months, thus the response rate (CR+PR) was 22%. None of the following parameters, tested prior to initiation of the therapy and 1-2 days after termination of each course of IL-2, correlated with the clinical response: WBC counts (total and differential), levels of blood CD4 and CD8 T cells, NK cells, monocytes and B cells, production of IL-1 and IL-1 inhibitor by monocytes, responsiveness to 3 mitogens, NK/LAK cell activity, and serum levels of IL-1 alpha, IL-2, soluble IL-2 receptor, and TNF alpha. The only prognostic parameter was the greater increase in the level of IL-2 receptor (Tac)-bearing lymphocytes in the responding patients after 1-3 cycles of IL-2. The data suggests that non-specific immune parameters have no prognostic value for patients undergoing IL-2-based immunotherapy.

Prognostic factors for survival in patients with advanced renal cell carcinoma treated with recombinant interleukin-2

A database of 327 patients with advanced Renal Cell Carcinoma (RCC) has been analyzed in order to identify potential baseline prognostic factors predicting for survival, following recombinant Interleukin-2 treatment (rIL-2). All patients received a continuous infusion (CIV). Eligibility criteria were uniform across studies, and included patients with an ambulatory performance status (PS), measurable disease, no CNS metastases, and no major organ compromise. Multivariate analyses identified baseline PS (ECOG 0 vs. 1), time from diagnosis to treatment (DTI greater than 24 months vs. less than or equal to 24 months), and the number of metastatic sites (1 vs. greater than or equal to 2, where lung, bone and other sites are considered as separate sites) as important predictors for survival. Patients can be classified into 4 subgroups, which are a function of the number of risk factors present. Median survival for each subgroup is 28, 17, 10 and 5 months, respectively. The model was validated in an independent cohort of 125 patients with RCC treated with subcutaneous (s/c) rIL-2, and predicted for survival accurately. By determining in which risk group category patients may fall, treating physicians may be better equipped to decide on patient management. The model may also be of value in order to stratify patients in randomized clinical trials.

Continuous infusion of recombinant interleukin-2 with or without autologous lymphokine activated killer cells for the treatment of advanced renal cell carcinoma

Data have been analysed for 327 patients with advanced renal cell carcinoma receiving a continuous infusion of recombinant interleukin 2 (rIL-2) alone (225 patients) or rIL-2 plus lymphokine activated killer (LAK) cells (102) on a normal oncology ward. Eligibility criteria were uniform across protocols, all patients having advanced progressive disease, but with an ambulatory performance status. The baseline characteristics of patients receiving rIL-2 alone did not differ significantly from those receiving LAK, with the exception that the LAK treated patients had a better performance status. Despite similar treatment intensity, toxicity was more severe in the patients receiving LAK. The addition of LAK did not lead to higher response rates or to prolonged response duration, progression-free survival or survival. This review confirms the activity of rIL-2 for the treatment of advanced renal cell carcinoma and demonstrates that the addition of LAK cells does not lead to increased efficacy.

Chemo-adoptive immunotherapy of nude mice implanted with human colorectal carcinoma and melanoma cell lines

The antitumor effects of chemotherapy, recombinant human interleukin-2 (IL-2), recombinant human interferon alpha A/D (IFN alpha), allogeneic human lymphokine-activated killer (LAK) cells, and antitumor monoclonal antibody (mAb), administered alone and in various combinations, were tested in athymic nude mice carrying human tumor xenografts. Treatment began 6-18 days after i.v. or i.p. inoculation of colorectal carcinoma or melanoma cell lines, when macroscopic growths were evident. Chemotherapy consisted of two or three courses of 5-fluorouracil (5-FU) or dacarbazine. IL-2 and/or IFN alpha were administered three to five times weekly for 1-3 weeks, usually starting 2-5 days after chemotherapy. Human LAK cells were infused once or twice weekly for 2 or 3 weeks concurrently with IL-2. In some experiments, murine anticolorectal carcinoma mAb (SF25) was administered. In both tumor systems, chemotherapy alone or immunotherapy alone (IL-2, IL-2 + LAK cells, IFN alpha, IL-2 + IFN alpha +/- LAK cells) had little or no therapeutic effects. Additive effects were obtained by combining chemotherapy with IL-2 and LAK cells or with IL-2 and IFN alpha. In the majority of the experiments, the most effective combination was chemotherapy + IL-2 + IFN alpha + LAK cells. Treatment with mAb was beneficial in the colorectal carcinoma system when combined with 5-FU + IL-2 or 5-FU + IL-2 + IFN alpha. Homing experiments with radiolabeled human and mouse LAK cells injected i.v. showed increased early accumulation in the liver and lungs, whereas freshly explanted mouse splenocytes localized mostly in the spleen and liver. The tissue distribution pattern of human LAK cells was similar in normal and tumor-bearing mice (with lung metastases). These findings suggest that combination of chemotherapy with cytokines and LAK cells can be partially effective for advanced solid human tumors even in the absence of the host's T-cell immune response. Preliminary experiments showed that tumor-specific, anti-melanoma T-cell clones were effective in local (s.c.) tumor growth inhibition (Winn assay) following coinjection with the autologous tumor cells.

Clinical applications of interleukin-2

Interleukin-2 (IL-2) is a cytokine with potent immunomodulating properties which has shown considerable antitumour activity in preclinical models. In clinical trials, the effects of IL-2 given by various routes and schedules have been investigated. IL-2 has been administered either as single drug or in combination with other cytokines and immunomodulating agents, chemo therapeutic agents, or reinfusions of ex vivo activated autologous cytotoxic effector cells. The results of published clinical studies with IL-2 based immunotherapy are reviewed in this paper.