Regulatory T cell frequency in patients with melanoma with different disease stage and course, and modulating effects of high-dose interferon-alpha 2b treatment.

BACKGROUND: High-dose interferon-alpha 2b (IFN-alpha 2b) is the only approved systemic therapy in the United States for the adjuvant treatment of melanoma. The study objective was to explore the immunomodulatory mechanism of action for IFN-alpha 2b by measuring serum regulatory T cell (Treg), serum transforming growth factor-beta (TGF-beta), interleukin (IL)-10, and autoantibody levels in patients with melanoma treated with the induction phase of the high-dose IFN-alpha 2b regimen. METHODS: Patients with melanoma received IFN-alpha 2b administered intravenously (20 MU/m2 each day from day 1 to day 5 for 4 consecutive weeks). Serum Treg levels were measured as whole lymphocytes in CD4+ cells using flow cytometry while TGF-beta, IL-10, and autoantibody levels were measured using enzyme-linked immunosorbent assays. RESULTS: Twenty-two patients with melanoma received IFN-alpha 2b treatment and were evaluated for Treg levels. Before treatment, Treg levels were significantly higher in patients with melanoma when compared with data from 20 healthy subjects (P = 0.001; Mann-Whitney test). Although a trend for reduction of Treg levels following IFN-α 2b treatment was observed (average decrease 0.29% per week), statistical significance was not achieved. Subgroup analyses indicated higher baseline Treg levels for stage III versus IV disease (P = 0.082), early recurrence versus no recurrence (P = 0.017), deceased versus surviving patients (P = 0.021), and preoperative neoadjuvant versus postoperative adjuvant treatment groups (not significant). No significant effects were observed on the levels of TGF-beta, IL-10, and autoantibodies in patients with melanoma treated with IFN-alpha 2b. CONCLUSIONS: Patients with melanoma in this study showed increased basal levels of Treg that may be relevant to their disease and its progression. Treg levels shifted in patients with melanoma treated with IFN-alpha 2b, although no firm conclusions regarding the role of Tregs as a marker of treatment response or outcome can be made at present.

Phase II study of pegylated arginine deiminase for nonresectable and metastatic hepatocellular carcinoma.

PURPOSE: It is well known that hepatocellular carcinoma (HCC) is an arginine auxotroph due to argininosuccinate synthetase I deficiency. This study's purpose was to evaluate the effects of pegylated arginine deiminase (ADI) in terms of toxicity, tumor response, alpha-fetoprotein (AFP) levels, and serum arginine levels. PATIENTS AND METHODS: Eighty patients were randomly assigned to receive either 80 IU/m(2) or 160 IU/m(2) of ADI weekly for up to 6 months. Adverse events, serum arginine, AFP levels, and antibody production against ADI were measured on a regular basis. In addition, disease response and time to progression according to the Response Evaluation Criteria in Solid Tumors (RECIST) and survival rates were evaluated. RESULTS: Four patients were excluded from the survival analysis because they developed exclusion criteria after randomization, but before first treatment. The number of patients in the two cohorts were similar (n = 37 in the low-dose cohort, n = 39 in the high-dose cohort). Mean (+/-SE) survival for all subjects was 15.8 months (474 days +/- 39 days) from time of diagnosis of unresectable disease. Arginine levels remained below baseline for 50 days while antibodies against ADI reached a plateau at approximately the same time. There were no deaths attributed to ADI treatment. Only two patients were withdrawn for immunogenic-related adverse events. Grade 2, 3, or 4 toxicities were recorded in 92, 19, and 0 patients, respectively. CONCLUSION: Pegylated ADI is a promising drug that capitalizes on a significant enzymatic deficiency in HCC. It is safe, well tolerated, and may benefit patients with unresectable HCC.

Immune signatures in human PBMCs of idiotypic vaccine for HCV-related lymphoproliferative disorders.

Hepatitis C virus (HCV) is one of the major risk factors for chronic hepatitis, which may progress to cirrhosis and hepatocellular carcinoma, as well as for type II mixed cryoglobulinemia (MC), which may further evolve into an overt B-cell non-Hodgkin's lymphoma (NHL). It has been previously shown that B-cell receptor (BCR) repertoire, expressed by clonal B-cells involved in type II MC as well as in HCV-associated NHL, is constrained to a limited number of variable heavy (VH)- and light (VL)-chain genes. Among these, the VK3-20 light chain idiotype has been selected as a possible target for passive as well as active immunization strategy. In the present study, we describe the results of a multiparametric analysis of the innate and early adaptive immune response after ex vivo stimulation of human immune cells with the VK3-20 protein. This objective has been pursued by implementing high-throughput technologies such as multiparameter flow cytometry and multiplex analysis of cytokines and chemokines.

A phase II study of capecitabine in the treatment of ovarian cancer resistant or refractory to platinum therapy: a multicentre Italian trial in ovarian cancer (MITO-6) trial.

PURPOSE: Capecitabine is an oral chemotherapeutic agent, already used in breast and colon cancer. Previous data showed encouraging results in the treatment of recurrent ovarian cancer. The aim of this study was to describe activity and toxicity of capecitabine in patients with platinum resistant or refractory ovarian cancer. METHODS: Patients were eligible if they had cytologically or histologically proven epithelial ovarian cancer, refractory or resistant to prior platinum-containing chemotherapy. Capecitabine was administered at the dose of 1,250 mg/m(2) twice daily on days 1-14 of a 21-day cycle for a maximum of six cycles. The primary end point of the study was activity in terms of objective response rate in according to RECIST criteria. A two-stage minimax design for phase II studies was used: at least four objective responses had to be reached among 32 evaluable patients to define the treatment active. RESULTS: Between March 2006 and October 2007, 36 patients were enrolled. All patients had ovarian cancer and 83.3% had previously received two or three lines of chemotherapy. Thirty-two patients were evaluable for response and included in the activity analysis. The objective response rate was 3.1% [95% exact confidence interval (CI): 0.08-16.22%], lower than the threshold required to define the treatment as active. The median progression free survival was 68 days (95% CI: 65-120). Haematological toxicity was not frequent. Nausea and fatigue were common, but never severe, and they were observed in 13 (37.1%) and 12 (34.2%) patients, respectively. Diarrhoea occurred in 11 patients (31.5%) and it was of grade 3 in 8.6% of cases. Grade 1-2 stomatitis was observed in seven patients (20%). Cardiovascular toxicity was reported in two cases, including a death for pulmonary embolism. CONCLUSIONS: Capecitabine is not active in platinum resistant non mucinous ovarian cancer, producing a response rate lower than that required by study design. Further trials are not warranted in these patients.

Pegylated arginine deiminase lowers hepatitis C viral titers and inhibits nitric oxide synthesis.

BACKGROUND: The arginine-degrading enzyme, arginine deiminase conjugated to polyethylene glycol (ADI-SS PEG 20,000 mw), reduces extracellular arginine, has minimal toxicity, decreases tumor burden and improves liver function in patients with chronic hepatitis C virus infection (HCV) and inoperable hepatocellular carcinoma (HCC). Reduced extracellular arginine inhibits viral replication through unknown mechanisms. It is hypothesized that ADI-SS PEG 20,000 mw reduces HCV viral titers through nitric oxide (NO)-dependent effects. METHODS: The effects of ADI-SS PEG 20,000 mw (dose, 160 IU/m2; three cycles of four once-weekly i.m. injections) on HCV titers, serum NO and plasma arginine, were evaluated using archived plasma from patients with HCC and HCV and in vitro cell model measurements of HCV replication. RESULTS: ADI-SS PEG 20,000 mw selectively inhibited HCV replication in vitro (IC50 = 0.027 IU/mL). Fifteen HCC/HCV patients completed treatment. The HCV titers were reduced by up to 99% in five out of 10 (50%) HCV-serotype 1b patients (P = 0.0093). These patients also experienced significant improvements in liver function (P = 0.0091). There were concomitant reductions of plasma arginine and serum NO levels. The HCV titer was not reduced in HCV-type 2c patients. CONCLUSION: Reduction of extracellular arginine by ADI-SS PEG 20,000 mw in HCC patients reduces HCV viral titers and improves liver function, possibly through suppression of NO.

Pegylated arginine deiminase treatment of patients with metastatic melanoma: results from phase I and II studies.

PURPOSE: Individuals with metastatic melanoma have a poor prognosis. Many human melanomas are auxotrophic for arginine, and arginine is not an essential amino acid in humans. We hypothesized that this auxotrophy may be therapeutically exploited. A novel amino acid-degrading enzyme (arginine deiminase) conjugated to polyethylene glycol (ADI-SS PEG 20,000 mw) was used to lower plasma arginine in individuals with metastatic melanoma. PATIENTS AND METHODS: Two cohort dose-escalation studies were performed. A phase I study in the United States enrolled 15 patients, and a phase I to II study in Italy enrolled 24 patients. The Italian patients also received two subsequent cycles of treatment, each consisting of four once-weekly injections of 160 U/m2. The goals of these studies were to determine pharmacokinetics (PK), pharmacodynamics (PD), safety, and the antitumor activity of ADI-SS PEG 20,000 mw. RESULTS: PK and PD studies indicated that a dose of 160 U/m2 lowered plasma arginine from a resting level of approximately 130 micromol/L to less than 2 micromol/L for at least 7 days; nitric oxide levels also were lowered. There were no grade 3 or 4 toxicities directly attributable to the drug. Six of 24 phase I to II patients responded to treatment (five partial responses and one complete response; 25% response rate) and also had prolonged survival. CONCLUSION Elimination of all detectable plasma arginine in patients with metastatic melanoma was well tolerated and may be effective in the treatment of this cancer. Further testing of ADI-SS PEG 20,000 mw in a larger population of individuals with metastatic melanoma is warranted.

Gender- and age-related distinctions for the in vivo prooxidant state in Fanconi anaemia patients.

Some selected oxidative stress parameters were measured in 56 Fanconi anaemia (FA) patients (42 untransplanted and 14 transplanted), 54 FA heterozygotes (parents) and 173 controls. Untransplanted FA patients showed a highly significant increase in leukocyte 8-hydroxy-2'-deoxyguanosine (8-OHdG) (P = 0.00003) and a borderline increase (P = 0.076) in urinary levels of 8-OHdG versus child controls. These increases were more pronounced in female FA patients (P = 0.00005 for leukocyte 8-OHdG and P = 0.021 for urinary 8-OHdG). Female FA patients also displayed a highly significant excess of spontaneous chromosomal breaks versus male patients (P = 0.00026), in the same female:male ratio ( approximately 1.4) as detected for both leukocyte and urine 8-OHdG levels. Plasma methylglyoxal (MGlx) levels were increased in untransplanted FA patients versus child controls (P = 0.032). The increases in leukocyte and urinary 8-OHdG and in MGlx levels were detected in young FA patients (< or =15 years), whereas patients aged 16-29 years failed to display any differences versus controls in the same age group. A significant increase in oxidized:reduced glutathione (GSSG:GSH) ratio was observed (P = 0.046) in the FA patients aged < or =15 years, whereas those aged 16-29 years, both untransplanted and transplanted, displayed a decrease (P = 0.06) in the GSSG:GSH ratio versus the controls of the respective age groups. No significant changes were detected in plasma levels of vitamin C, vitamin E or uric acid. Transplanted FA patients showed lesser alterations in leukocyte 8-OHdG and in GSSG:GSH ratio versus untransplanted patients. The parents of FA patients displayed a significant increase in plasma MGlx levels (P = 0.0014) versus adult controls. The results suggest a gender- and age-related modulation of oxidative stress in FA patients. The observed increase in urinary 8-OHdG in untransplanted FA patients suggests a proficient removal of oxidized DNA bases.

Pegylated arginine deiminase treatment of patients with unresectable hepatocellular carcinoma: results from phase I/II studies.

PURPOSE: Recently, we reported that a large number of human hepatocellular cancer (HCC) cell lines were auxotrophic for arginine. Here we report the results obtained with the amino acid-degrading enzyme arginine deiminase (ADI) conjugated to polyethylene glycol (ADI-SS PEG 20,000 mw) as a means of lowering plasma arginine to treat HCC. The study was a cohort dose-escalation phase I/II study. PATIENTS AND METHODS: Pharmacodynamic studies indicated an ADI-SS PEG 20,000 mw dose level of 160 U/m(2) was sufficient to lower plasma arginine from a resting level of approximately 130 micromol/L to below the level of detection (< 2 micromol/L) for more than 7 days, a dose later defined as the optimal biologic dose. All patients were to receive three cycles at the optimum biologic dose. RESULTS: This therapy was well tolerated, even in patients who had no detectable plasma arginine for 3 continuous months of therapy. Of the 19 patients enrolled, two had a complete response, seven had a partial response, seven had stable disease, and three had progressive disease. The median survival for the 19 patients enrolled on this study was 410 days, with four patients still alive at present (> 680 days). CONCLUSION: Elimination of all detectable plasma arginine in patients with HCC was well tolerated and seemed to be effective in the treatment of some patients with HCC. Further testing of ADI-SS PEG 20,000 mw in a larger population of individuals with HCC as well as other human tumors auxotrophic for arginine is warranted.