A phase III comparison of methyl-CCNU + vincristine with or without BCG + allogeneic tumor cells in metastatic melanoma

Summary Sixty-two patients with metastatic malignant melanoma were randomized to treatment with either (a) methyl-CCNU (200 mg/m², PO every 8 weeks) plus vincristine (2 mg IV every 4 weeks), or (b) the same chemotherapy plus intradermal (ID) injections of irradiated (15,000 rads) allogeneic (fresh-frozen) melanoma cells (1–2×10⁸) admixed with BCG (Glaxo, 2–4.5×10⁶ organisms) every 2 weeks. Treatment cycles were repeated every 8 weeks until tumor progression. Seven (2 CR, 5 PR) objective remissions were noted among 31 patients (22.5%) treated with chemotherapy alone, whereas six (3 CR, 3 PR) objective remissions were noted among 31 patients (19%) treated with chemoimmunotherapy (P>0.05). The medians for remission duration (6 months) and survival (6.5 months) in the chemotherapy group did not differ significantly from the medians for remission duration (8 months) and survival (8 months) in the chemoimmunotherapy group. The patients manifested no unexpected toxicity. Hematologic toxicity was experienced by patients on both regimens; however, those receiving chemoimmunotherapy rebounded more quickly.     

Chemoimmunotherapy for melanoma with dacarbazine and 2,4-dinitrochlorobenzene elicits a specific T cell-dependent immune response

An empirically established chemoimmunotherapy for metastatic melanoma combines the systemic administration of the chemotherapeutic agent dacarbazine (DTIC) with the epifocal application of the contact sensitizer 2,4-dinitrochlorobenzene (DNCB) on cutaneous metastases. Although this therapy yields high response rates resulting in prolonged survival, the mechanisms involved remain unknown. Here, we investigated whether treatment of tumor-bearing mice with DTIC and DNCB resulted in a specific immune response against the tumor. Subcutaneous (s.c.) tumors and lung metastases were induced in C57BL/6 mice by injecting syngeneic B16-melanoma cells s.c. or into the lateral tail vein, respectively. Mice were treated with intraperitoneal injections of DTIC followed by epifocal application of DNCB. This therapeutic approach significantly reduced the growth of s.c. tumors as well as lung metastases. Our data showed that the effector mechanisms involved are dependent on T cells. No therapeutic effect was observed in immunodeficient RAG-1(-/-) mice, or when the contact sensitizer DNCB was replaced by skin irritants (croton oil or tributyltin). Splenic lymphocytes obtained from treated mice displayed a three-fold higher specific cytolytic activity against B16 cells than in tumor-bearing controls. Both CD8(+) and CD4(+) T cells were able to lyse B16 cells. No changes were observed in natural killer (NK) cell activity. Likewise, tumor-infiltrating lymphocytes (TIL) of treated mice showed higher cytolytic activity than that of controls. Analysis of cytokine expression in s.c. tumors revealed increased mRNA levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) in treated tumors. Together, these findings demonstrate the ability of DTIC/DNCB treatment to induce an effective T cell-dependent host immune response against a syngeneic tumor.     

Granulocyte/macrophage-colony-stimulating-factor plus interleukin-2 plus interferon α in the treatment of metastatic renal cell carcinoma: a pilot study

 Granulocyte/macrophage-colony-stimulating factor (GM-CSF) plays a central role in the differentiation and function of dendritic cells, which are crucial for the elicitation of MHC-restricted T cell responses. Preclinical and the first clinical data provide a rationale for the application of GM-CSF in immunotherapy of cancer. Ten patients with renal cell carcinoma stage IV (Holland/Robson) were treated in this pilot study. Therapy was started with GM-CSF alone (2 weeks). Interleukin (IL-2) and interferon α (IFNα) were added sequentially (3 weeks GM-CSF plus IL-2 or IFNα, 3 weeks GM-CSF plus IL-2 plus IFNα). Therapy was performed on an outpatient basis. The cytokine regimen was evaluated for toxicity, clinical response and immunomodulatory effects [fluorescence-activated cell sorting analysis of peripheral blood mononuclear cells (PBMC), mixed-lymphocyte reaction and cytotoxicity of PBMC]. GM-CSF treatment caused a significant increase in the number of PBMC expressing costimulatory molecules. Addition of IL-2 and IFNα led to an increase in CD3⁺, CD4⁺, CD8⁺ and CD56⁺ PBMC in week 9. In an autologous mixed-lymphocyte reaction a 2.1-fold increase in T cell proliferation was observed after 2 weeks of GM-CSF treatment, and cytotoxicity assays showed changes in natural-killer- (NK)- and non-NK-mediated cytotoxicity in some patients. Two patients achieved partial remission, one patient had a mixed response. The toxicity of the regimen was mild to moderate with fever, flu-like symptoms and nausea being observed in most patients. Severe organ toxicity was not observed. We conclude that GM-CSF might be useful for immunotherapy of renal cell carcinoma, especially in combination with T-cell-active cytokines. Further studies are warranted. Received: 16 March 2000 / Accepted: 10 August 2000     

Pilot study of treatment of biochemotherapy-refractory stage IV melanoma patients with autologous dendritic cells pulsed with a heterologous melanoma cell line lysate

Eleven AJCC stage IV melanoma patients with progressive disease after treatment with biochemotherapy were treated with autologous dendritic cells pulsed with heterologous tumor cell lysates. The vaccine used mature DCs (CD1a⁺⁺⁺, CD40⁺⁺, CD80⁺⁺, CD83⁺, and CD86⁺⁺⁺) generated from peripheral blood monocytes in the presence of GM-CSF and IL-4. After 7 days, DCs were matured with a defined cocktail of cytokines (IL-1+IL-6+TNF-+PGE₂) and simultaneously pulsed with lysates of heterologous melanoma cell lines, for 2 days. A total of 4×10⁶ DCs was injected monthly under ultrasound control in an inguinal lymph node of normal appearance. The study was closed when all patients died as a consequence of tumor progression. No sign of toxicity was observed during the study. One patient experienced a partial response lasting 5 months, and two patients showed a mixed response which lasted 3 months. The median survival of the whole group was 7.3 months (range 3–14 months). This vaccination program had specific antitumoral activity in highly pretreated and large tumor burden stage IV melanoma patients and was well tolerated. The clinical responses and the median survival of the group of patients, together with the low toxicity of our DC vaccine, suggest that this approach could be applied to earlier AJCC stage IV melanoma patients.     

Effect of treatment with dimethyl triazeno imidazole carboxamide (DTIC,NSC-45388) or 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU,NSC-409962) plus vincristine (NSC-67574) on lymphocyte reactivity of melanoma patients

Summary Fourteen patients with surgically incurable malignant melanoma treated with dimethyl triazeno imidazole carboxamide (DTIC) (2 mg/kg/day i.v. × 10) and 18 patients treated with the combination of 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) (150 mg/m² i.v.) plus vincristine (2 mg/m² i.v.) on day 1 only, were tested for lymphocyte reactivity against melanoma cells before and after treatment. Neither chemotherapeutic regimen regularly affected lymphocyte reactivity, either in the presence of fetal calf serum or in the presence of the patients' autologous serum when tested 1 month after treatment. Three patients receiving repeated DTIC therapy and six patients receiving repeated BCNU plus vincristine therapy exhibited little variation in lymphocyte reactivity throughout the course of treatment.     

A phase II study of interferon α and low-dose subcutaneous interleukin-2 in advanced renal cell carcinoma

 The activity of the drugs employed in the treatment of metastatic renal cell carcinoma, including biological response modifiers, is limited; one of the aims of clinical research in this area is to maintain the benefits of treatment whilst reducing its toxicity to a minimum level. We have evaluated toxicity and response of the combined administration of recombinant interferon α (IFNα) and low-dose subcutaneous (s.c.) recombinant interleukin-2 (IL-2) in patients with advanced renal cell carcinoma. A group of 20 previously untreated patients with advanced renal cell carcinoma were included in the study. Treatment consisted of 3 MU/m² recombinant IFNα daily i.m. continuously, and 0.5 MU/m² recombinant IL-2 twice a day s.c. on days 1–5 for the first week, followed by 1 MU/m² twice a day for 5 days in the following weeks. For IL-2, a 1-week rest was allowed after 4 weeks of treatment. Response was assessed after 3 months of therapy. Three objective responses were seen, one complete and two partial. Eight patients had stable disease. The median time to progression was 6 months; the median survival for all patients was 14 months. Side-effects were low, limited to grades 1 and 2 in the majority of patients, and included fever, anemia, leukopenia, dyspnea, and abnormalities of liver and renal function tests. Any flu-like syndrome was judged moderate in most patients; however, one-third of the patients refused treatment mostly because of the flu-like syndrome. One of these was the patient experiencing a complete response, who virtually received IFNα alone. This regimen, similar to others employed in the treatment of advanced renal cell carcinoma, produced a 15% response rate (95% confidence interval, 0–31%) with 14 months median survival, moderate toxicity and low cost, and required no hospitalization. These data seem to indicate an effectiveness comparable to, and a toxicity lower than, that of regimens employing higher doses of IL-2. Received: 25 March 1997 / Accepted: 22 May 1997     

Curcumin Analog DM-1 in Monotherapy or Combinatory Treatment with Dacarbazine as a Strategy to Inhibit In Vivo Melanoma Progression

Malignant melanoma is a highly aggressive form of skin cancer with a high mortality rate if not discovered in early stages. Although a limited number of treatment options for melanoma currently exist, patients with a more aggressive form of this cancer frequently decline treatment. DM-1 is a sodium phenolate and curcumin analog with proven anticancer, anti-proliferative and anti-metastatic properties. In this paper, the DM-1 compound showed in vivo antitumor activity alone or in combination with chemotherapeutic DTIC in B16F10 melanoma-bearing mice. Beneficial effects such as melanoma tumor burden reduction with pyknotic nuclei, decreased nuclei/cytoplasmic ratio and nuclear degradation occurred after DM-1 treatment. No toxicological changes were observed in the liver, kidneys, spleen and lungs after DM-1 monotherapy or DTIC combined therapy. DTIC+DM-1 treatment induced the recovery of anemia arising from melanoma and immunomodulation. Both DM-1 treatment alone and in combination with DTIC induced apoptosis with the cleavage of caspase-3, -8 and -9. Furthermore, melanoma tumors treated with DM-1 showed a preferential apoptotic intrinsic pathway by decreasing Bcl-2/Bax ratio. Considering the chemoresistance exhibited by melanoma towards conventional chemotherapy drugs, DM-1 compound in monotherapy or in combination therapy provides a promising improvement in melanoma treatment with a reduction of side effects.     

Chronic chemoimmunotherapy achieves cure of spontaneous murine mammary tumors via persistent blockade of posttherapy counter-regulation

Intratumoral delivery of IL-12 and GM-CSF induces local and systemic antitumor CD8(+) T cell activation and tumor kill. However, the effector response is transient and is rapidly countered by CD4(+) Foxp3(+) T suppressor cell expansion. To determine whether depletion of the pre-existing T suppressor cell pool prior to treatment could diminish posttherapy regulatory cell resurgence, FVBneuN mice bearing advanced spontaneous mammary tumors were treated with cyclophosphamide (CY) 1 d before IL-12/GM-CSF therapy. Administration of CY mediated a significant delay in the post-IL-12/GM-CSF T suppressor cell rebound, resulting in a 7-fold increase in the CD8(+) CTL/T suppressor cell ratio, a 3-fold enhancement of CTL cytotoxicity, and an extension of the effector window from 3 to 7 d. In long-term therapy studies, chronic chemoimmunotherapy promoted a dramatic enhancement of tumor regression, resulting in complete cure in 44% of the mice receiving CY plus IL-12/GM-CSF. Tumor eradication in the chronic therapy setting was associated with the ability to repeatedly rescue and maintain cytotoxic CD8(+) T cell activity. These findings demonstrated that chronic administration of CY in conjunction with immune therapy enhances the initial induction of antitumor T effector cells and, more importantly, sustains their cytotoxic activity over the long-term via persistent blockade of homeostatic counter-regulation.     

Treatment with GM-CSF and IL-2 in patients with metastatic colorectal carcinoma induced high serum levels of neopterin and sIL-2R,an indicator of immune suppression

Cytokines may enhance the effect of therapeutic monoclonal antibodies (mAb). Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-2 (IL-2) have been shown to increase ADCC levels. GM-CSF may augment the induction of an idiotypic network response (anti-tumour immunity). The clinical anti-tumour effect of a combination of mouse mAb17-1A-1A [anti-colorectal carcinoma (CRC)], and GM-CSF was, however, not enhanced by the addition of IL-2. In the present study, some immune functions considered to be involved in mAb-mediated tumour cell killing were analysed in patients receiving GM-CSF and GM-CSF/IL-2 respectively together with the mAb17-1A-1A. Ten patients received mAb17-1A and GM-CSF, and ten patients mAb17-1A with GM-CSF and IL-2. During a 10- day cytokine treatment period, a significantly higher increase in white blood cell counts was noted in the GM-CSF/IL-2 treatment group as compared to GM-CSF-treated patients. In the GM-CSF/IL-2 group, significantly higher serum concentrations of neopterin and soluble IL-2 receptor (sIL-2R) respectively were induced as compared to GM-CSF-treated patients. However, the ADCC of peripheral blood mononuclear cells (PBMC) against a CRC cell line was significantly higher in the GM-CSF group than in the GM-CSF/IL-2 group. The frequencies of patients developing human anti-mouse antibodies (HAMA) and anti-idiotypic antibodies were the same in both groups, while serum concentrations were significantly lower in the GM-CSF/IL-2 group as compared to the GM-CSF group. GM-CSF/IL-2 therapy seems to induce an immune suppressive stage compared to GM-CSF alone affecting cytotoxic mononuclear cells and B cells, which might be mediated through the neopterin metabolic pathway or other inducible immune suppressive factors such as reactive oxygen and nitrogen intermediates.     

Adjuvant adoptive immunotherapy with tumour-infiltrating lymphocytes and modulated doses of interleukin-2 in 22 patients with melanoma, colorectal and renal cancer, after radical metastasectomy, and in 12 advanced patients

 Adoptive tumour infiltrating lymphocytes (TIL) in combination with a modulated dosage of interleukin-2 (IL-2) can be used with acceptable toxicity in the treatment of immunogenic tumours. Following an experience of reinfusion in advanced melanoma, colorectal and renal cancer patients, treatment was given to disease-free patients after metastasectomy. The high risk of relapse and favourable ratio between reinfused TIL and possible microscopic residual disease determined this choice of adjuvant treatment. A group of 12 patients with advanced disease (7 melanoma, 4 colorectal carcinoma, 1 kidney carcinoma) were treated with TIL (median 5.8×10¹⁰ cells) and IL-2 (West’s schedule) modulated towards a lower dosage (from 12 to 6 MIU/day) in order to maintain an acceptable level of toxicity. As treatment was well tolerated, it was offered to another 22 patients in an adjuvant setting after metastasectomy (11 melanoma, 10 colorectal carcinoma, 1 renal cancer), the median dose of TIL reinfused being 4.95×10¹⁰ cells. No objective response was observed in advanced patients: all patients progressed after a median of 1.5 months (0–8 months) and median survival was 8 months (3–22+ months). Thirteen patients from the second group are still disease-free after a median of 23+ months (9+–47+ months). The remaining 9 patients relapsed after a median of 5 months (3–18 months). Toxicity was moderate as clinical and hepatic/renal function parameters were used to assess the need for dose reductions. Consequently, there was great diversity in IL-2 dosages administered. In particular, there seemed to be a difference in IL-2 doses administered between disease-free cases and those who progressed (17.5 MIU/day versus 7 MIU/day in melanoma patients; 11.2 MIU/day versus 7.1 MIU/day in colorectal cancer patients). By contrast, no differences were observed between number of TIL reinfused and clinical response. Phenotypical characteristics of reinfused TIL were similar to those reported in the literature: 97% were CD3 and 92% were CD8. Aspecific cytolytic activity was evaluated on 12 cases whereas, in 2 melanoma cases, autologous tumour tissue was available for the specific cytotoxicity test. Perforin levels in TIL measured at the end of culture were generally high or very high. Cytokine levels were measured on the supernatant at the end of culture, with an estreme variability in results. Finally, ζ chain and p56^lck were histologically assessed on the resected tissue from which TIL were cultivated. There were virtually none of the former and a complete absence of the latter, which concurs with data reported in the literature. The same immunocytochemical analysis was carried out on TIL at the end of culture. This time an almost complete restoration of both functions was seen, especially in melanoma patients, who are still free from disease. The study is on-going and it has been decided to focus on disease-free patients after metastasectomy in order to increase the number and possibility of clinical and histological correlations.     

A phase II trial of vaccination with autologous, tumor-derived heat-shock protein peptide complexes Gp96, in combination with GM-CSF and interferon-α in metastatic melanoma patients

The aim of this study was to determine the immunogenicity and antitumor activity of autologous, tumor-derived heat shock protein gp96-peptide complex vaccine (HSPPC-96; Oncophage®) given with GM-CSF and IFN-α in pre-treated metastatic (AJCC stage IV) melanoma patients. Patients underwent surgical resection of metastatic lesions for HSPPC-96 production. HSPPC-96 was administered subcutaneously (s.c.) in four weekly intervals (first cycle). Patients with more available vaccine and absence of progressive disease received four additional injections in 2-week intervals (second cycle) or more. GM-CSF was given s.c. at the same site at days –1, 0 and +1, while IFN-α (3 MU) was administered s.c. at a different site at days +4 and +6. Antigen-specific anti-melanoma T and NK lymphocyte response was assessed by enzyme-linked immunospot assay on peripheral blood mononuclear cells obtained before and after vaccination. Thirty-eight patients were enrolled, 20 received at least four injections (one cycle) of HSPPC-96 and were considered assessable. Toxicity was mild and most treatment-related adverse events were local erythema and induration at the injection site. Patients receiving at least four injections of HSPPC-96 were considered evaluable for clinical response: of the 18 patients with measurable disease post surgery, 11 showed stable disease (SD). The ELISPOT assay revealed an increased class I HLA-restricted T and NK cell-mediated post-vaccination response in 5 out of 17 and 12 out of the 18 patients tested, respectively. Four of the five class I HLA-restricted T cell responses fall in the group of SD patients. Vaccination with autologous HSPPC-96 together with GM-CSF and IFN-α is feasible and accompanied by mild local and systemic toxicity. Both tumor-specific T cell-mediated and NK cell responses were generated in a proportion of patients. Clinical activity was limited to SD. However, both immunological and clinical responses were not improved as compared with those recorded in a previous study investigating HSPPC-96 monotherapy.L.P. and R.P. have equally contributed to the work.     

Phase I/II study of treatment with matured dendritic cells with or without low dose IL-2 in patients with disseminated melanoma

Background In the present study, we have examined whether treatment of patients with metastatic melanoma with matured dendritic cell (DC) vaccines with or without low dose IL-2 may improve treatment outcomes. Methods Sixteen patients received DC vaccines (DCs) sensitized with autologous melanoma lysates and 18 patients received DCs sensitized with peptides from gp100, MART-1, tyrosinase, MAGE-3.A2, MAGE-A10 and NA17. IL-2 was given subcutaneously (sc) at 1 MU/m² on the second day after each injection for 5–14 days in half of each group. DCs were given by intranodal injection. Results There were 2 partial responses (PR) and 3 with stable disease (SD) in the nine patients receiving DCs + peptides + IL-2, and 1 PR and 1 SD in nine patients treated with DCs + peptides without IL-2. There were only two patients with SD in the group receiving DCs + autologous lysates and no IL-2. Median overall survival for all patients was very good at 18.5 months but this was most probably due to selection of a favourable group of patients for the study. There was no significant difference in survival between the groups by log rank analysis. Treatment was not associated with significant side effects. The quality and yield of the DCs in the preparations were generally good. Conclusions We conclude that mature DC preparations may be superior to immature DC preparations for presentation of melanoma peptides and that IL-2 may increase clinical responses to the DCs plus peptides. However, in our view the low response rates do not justify the cost and complexity of this treatment approach.     

Metformin pretreatment reduces effect to dacarbazine and suppresses melanoma cell resistance

Oxidative stress role on metformin process of dacarbazine (DTIC) inducing resistance of B16F10 melanoma murine cells are investigated. To induce resistance to DTIC, murine melanoma cells were exposed to increasing concentrations of dacarabazine (DTIC-res group). Metformin was administered before and during the induction of resistance to DTIC (MET-DTIC). The oxidative stress parameters of the DTIC-res group showed increased levels of malondialdehyde (MDA), thiol, and reduced nuclear p53, 8-hydroxy-2?-deoxyguanosine (8-OH-DG), nuclear factor kappa B (NF-?B), and Nrf2. In presence of metformin in the resistant induction process to DTIC, (MET-DTIC) cells had increased antioxidant thiols, MDA, nuclear p53, 8-OH-DG, Nrf2, and reducing NF-?B, weakening the DTIC-resistant phenotype. The exclusive administration of metformin (MET group) also induced the cellular resistance to DTIC. The MET group presented high levels of total thiols, MDA, and reduced percentage of nuclear p53. It also presented reduced nuclear 8-OH-DG, NF-?B, and Nrf2 when compared with the control. Oxidative stress and the studied biomarkers seem to be part of the alterations evidenced in DTIC-resistant B16F10 cells. In addition, metformin administration is able to play a dual role according to the experimental protocol, preventing or inducing a DTIC-resistant phenotype. These findings should help future research with the aim of investigating DTIC resistance in melanoma.     

Pro- and anti-inflammatory responses are regulated simultaneously from the first moments of septic shock

The relationships between cytokine responses in septic shock are currently poorly understood. Some studies have pointed to a biphasic model, with an initial proinflammatory phase, followed by a reactive, anti-inflammatory response to explain the pathogenesis of the most severe form of sepsis. However, evidence for the coexistence of both responses has been found. In this study, the plasma levels of 17 cytokines and chemokines, in 20 patients with septic shock, 11 patients with systemic inflammatory response syndrome (SIRS), during the first 24 hours following diagnosis, and 10 healthy controls, were analyzed and compared. Patients with septic shock showed increased levels of IL-6, IL-8, MCP-1, MIP-1β, IFN-γ, GM-CSF and IL-10 compared to healthy controls. Patients with SIRS showed higher levels of IL-6, IL-8, MCP-1, MIP-1β, G-CSF and IL-10 than controls. Patients with septic shock showed higher levels of IL-8, GM-CSF, MIP-1β than those with SIRS. The Spearman test demonstrated a positive association between the pro-inflammatory mediators IL-6, IL-8, MCP-1, MIP-1β, IFN-γ, GM-CSF and the immunomodulatory cytokine IL-10 in septic shock. Consequently, correlation studies supported the notion that secretion of pro- and anti-inflammatory mediators in septic shock occurs as a simultaneous immune response program initiated early in the course of the disease, revealing that both types of cytokine play a role from the very beginning of this life-threatening condition.     

Subcutaneous recombinant gamma interferon in cancer patients: toxicity,pharmacokinetics, and immunomodulatory effects

Summary Recombinant gamma interferon (r-IFN) was administered s. c. daily to 26 patients with advanced cancer. Patients were assigned to one of six doses: 0.5, 1, 2, 4, 6, or 8 million units (MU)/m² per d. The major toxicities were an influenza-like syndrome and fever, seen in all patients. Dose limiting toxicity occurred in 4 of 4 patients treated at 8 MU/m². One patient with nodular poorly differentiated lymphocytic lymphoma had a mixed response, and two patients with renal cell cancer have had stabilization of disease for >10 and >12 months. Pharmacokinetic analysis, by radioimmunoassay, revealed mean serum r-IFN concentrations up to 17 ng/ml, with maximal serum levels noted 6 to 13 h after injection. In vivo immunomodulation was assessed by natural killer (NK) cytotoxicity, monocyte activation as determined by cell surface expression of HLA-Dr, and peripheral blood mononuclear cell phenotype analysis by flow cytometry. The mean T₄/T₈ ratio increased from 2.1 pretreatment to 4.1 after 24 h of treatment, but returned to baseline after 7 and 28 days of treatment. Augmentation of NK function was noted after 7 days of treatment. Monocyte cell surface expression of HLA-Dr increased after 28 days of treatment at the three lowest doses. In conclusion, daily s. c. r-IFN can be easily administered on an outpatient basis with minimal local skin toxicity, results in prolonged serum levels, and is associated with immunological changes of potential antitumor significance. Further study of the in vivo immunomodulatory effects induced by r-IFN is indicated to help define the optimal treatment regimen.Recipient of a Clinical Investigator Award CA 01030 from the National Cancer Institute, NIH, DHHS. Supported by the Clinical Research Division of the Schering Corporation. A portion of this work was conducted at the Clinical Research Center of the University of Washington, supported by the NIH Grant RR-37. Additional support provided by the National Cancer Institute Grant CA 09515     

Sequential administration of interferon γ and interleukin-2 in metastatic renal cell carcinoma: results of a phase II trial

Background: Because of the known efficacy of several cytokines in the treatment of advanced renal cell cancer (RCC), we have conducted a phase II trial of the efficacy and toxicity of subcutaneous interferon γ (IFNγ) and interleukin-2 (IL-2). Methods: 63 patients with progressive metastatic RCC were treated with 100 μg recombinant IFNγ1b administered three times weekly during weeks 1 and 2 and with 4.5 MU recombinant IL-2 administered on 4 consecutive days during weeks 3 and 4, every 6 weeks. Results: 11% of patients had an objective response (CR: 3%, PR: 8%), 33% had SD. Toxicity was generally mild. The median duration of remissions (CR + PR) was 9.6 months; the median duration of SD 8 months. A significant survival benefit was evident at a median observation time of 51 months for patients (44%) responding to therapy (P < 0.0001). Conclusions: we conclude that sequential treatment with IFNγ and IL-2 may prolong survival in patients with metastatic RCC responding to therapy. Received: 2 April 2000 / Accepted: 21 April 2000     

Acid ceramidase expression modulates the sensitivity of A375 melanoma cells to dacarbazine

Dacarbazine (DTIC) is the treatment of choice for metastatic melanoma, but its response in patients remains very poor. Ceramide has been shown to be a death effector and to play an important role in regulating cancer cell growth upon chemotherapy. Among ceramidases, the enzymes that catabolize ceramide, acid ceramidase (aCDase) has been implicated in cancer progression. Here we show that DTIC elicits a time- and dose-dependent decrease of aCDase activity and an increase of intracellular ceramide levels in human A375 melanoma cells. The loss of enzyme activity occurred as a consequence of reactive oxygen species-dependent activation of cathepsin B-mediated degradation of aCDase. These events preceded autophagic features and loss of cell viability. Down-regulation of acid but not neutral or alkaline ceramidase 2 resulted in elevated levels of ceramide and sensitization to the toxic effects of DTIC. Conversely, inducible overexpression of acid but not neutral ceramidase reduced ceramide levels and conferred resistance to DTIC. In conclusion, we report that increased levels of ceramide, due to enhanced degradation of aCDase, are in part responsible for the cell death effects of DTIC. These results suggest that down-regulation of aCDase alone or in combination with DTIC may represent a useful tool in the treatment of metastatic melanoma.     

Stimulation of IL-12 secretion by GM-CSF in advanced cancer patients

In addition to its efficacy in the treatment of chemotherapy-induced neutropenia, recent evidence would suggest that GM-CSF may have immunomodulatory effects on anticancer immunity. In particular, GM-CSF has been proven to promote dendritic cell maturation, with following potential stimulation of the anticancer cytokine, IL-12. Unfortunately, at present there are only few and controversial results on GM-CSF effects on IL-12 secretion in cancer patients. This preliminary study was performed to evaluate IL-12 response to an acute injection of GM-CSF in human neoplasms. The study included 20 advanced cancer patients, who received GM-CSF for chemotherapy-induced neutropenia. GM-CSF was injected at 3 micrograms/kg at 8.00 A.M., and venous blood samples were drawn before GM-CSF, and at 4, 8, 12 and 24 hours after its injection. Serum levels of IL-12 were measured by an enzyme immunoassay. High basal levels of IL-12 were seen in 8/20 patients. In patients with abnormally high pretreatment levels of IL-12, no significant change occurred in IL-12 mean serum concentration after GM-CSF administration. In contrast, patients with normal baseline levels of IL-12 showed a significant increase in IL-12 mean concentrations in response to GM-CSF, with a peak after 12 hours. This preliminary study seems to show that GM-CSF may acutely stimulate IL-12 secretion in cancer patients. Further studies are required to evaluate the effects of chronic GM-CSF administration, and the impact of GM-CSF-induced secretion of IL-12 on the efficacy of the immunotherapies of cancer with cytokines, such as IL-2. In any case, this study would justify further research in the emerging oncological applications of GM-CSF as an immunomodulatory agent on host anticancer defenses.