Multiplex immunohistochemistry accurately defines the immune context of metastatic melanoma.

A prospective study explored the heterogeneous nature of metastatic melanoma using Multiplex immunohistochemistry (IHC) and flow cytometry (FACS). Multiplex IHC data quantitated immune subset number present intra-tumoral (IT) vs the tumor stroma, plus distance of immune subsets from the tumor margin (TM). In addition, mIHC showed a close association between the presence of IT CD8+ T cells and PDL1 expression in melanoma, which was more prevalent on macrophages than on melanoma cells. In contrast, FACS provided more detailed information regarding the T cell subset differentiation, their activation status and expression of immune checkpoint molecules. Interestingly, mIHC detected significantly higher Treg numbers than FACS and showed preferential CD4+ T cell distribution in the tumor stroma. Based on the mIHC and FACS data, we provide a model which defines metastatic melanoma immune context into four categories using the presence or absence of PDL1+ melanoma cells and/or macrophages, and their location within the tumor or on the periphery, combined with the presence or absence of IT CD8+ T cells. This model interprets melanoma immune context as a spectrum of tumor escape from immune control, and provides a snapshot upon which interpretation of checkpoint blockade inhibitor (CBI) therapy responses can be built.

Efficacy and toxicity of treatment with the anti-CTLA-4 antibody ipilimumab in patients with metastatic melanoma after prior anti-PD-1 therapy.

BACKGROUND: Recent phase III clinical trials have established the superiority of the anti-PD-1 antibodies pembrolizumab and nivolumab over the anti-CTLA-4 antibody ipilimumab in the first-line treatment of patients with advanced melanoma. Ipilimumab will be considered for second-line treatment after the failure of anti-PD-1 therapy. METHODS: We retrospectively identified a cohort of 40 patients with metastatic melanoma who received single-agent anti-PD-1 therapy with pembrolizumab or nivolumab and were treated on progression with ipilimumab at a dose of 3 mg kg(-1) for a maximum of four doses. RESULTS: Ten percent of patients achieved an objective response to ipilimumab, and an additional 8% experienced prolonged (>6 months) stable disease. Thirty-five percent of patients developed grade 3-5 immune-related toxicity associated with ipilimumab therapy. The most common high-grade immune-related toxicity was diarrhoea. Three patients (7%) developed grade 3-5 pneumonitis leading to death in one patient. CONCLUSIONS: Ipilimumab therapy can induce responses in patients who fail the anti-PD-1 therapy with response rates comparable to previous reports. There appears to be an increased frequency of high-grade immune-related adverse events including pneumonitis that warrants close surveillance.

Response to MAPK pathway inhibitors in BRAF V600M-mutated metastatic melanoma.

WHAT IS KNOWN AND OBJECTIVE: The management of metastatic melanoma has changed significantly in the past decade with the development of immunotherapies and targeted molecular therapies. Trials of targeted therapies have focused mainly on patients with the most common BRAF V600 mutations, namely V600E/K substitutions, with very little information available on the benefit of targeted therapies on less commonly occurring mutations such as V600R/D and M. CASE SUMMARY: We present a 54-year-old man with metastatic melanoma harbouring a rare BRAF V600M mutation, who experienced clinical and radiological response to combined therapy with the BRAF inhibitor dabrafenib and MEK inhibitor trametinib. WHAT IS NEW AND CONCLUSION: As our understanding of these therapies evolves and an increasing number of patients have mutational testing performed, there is a clear imperative--as highlighted by this case--to test for rarer mutations and facilitate their inclusion both in everyday practice and in future clinical trials.

Characteristics of pyrexia in BRAFV600E/K metastatic melanoma patients treated with combined dabrafenib and trametinib in a phase I/II clinical trial.

BACKGROUND: Pyrexia is a frequent adverse event with combined dabrafenib and trametinib therapy (CombiDT), but little is known of its clinical associations, etiology, or appropriate management. PATIENTS AND METHODS: All patients on the BRF133220 phase I/II trial of CombiDT treated at the standard dose (150/2) were included for assessment of pyrexia (n = 201). BRAF and MEK inhibitor-naïve patients (n = 117) were included for efficacy analyses. Pyrexia was defined as temperature ≥38°C (≥100.4(°)F) or related symptoms. RESULTS: Fifty-nine percent of patients developed pyrexia during treatment, 24% of which had pyrexia symptoms without a recorded elevation in body temperature. Pyrexia was grade 2+ in 60% of pyrexia patients. Median time to onset of first pyrexia was 19 days, with a median duration of 9 days. Pyrexia patients had a median of two pyrexia events, but 21% had three or more events. Various pyrexia management approaches were conducted in this study. A trend was observed between dabrafenib and hydroxy-dabrafenib exposure and pyrexia. No baseline clinical characteristics predicted pyrexia, and pyrexia was not statistically significantly associated with treatment outcome. CONCLUSIONS: Pyrexia is a frequent and recurrent toxicity with CombiDT treatment. No baseline features predict pyrexia, and it is not associated with clinical outcome. Dabrafenib and metabolite exposure may contribute to the etiology of pyrexia. The optimal secondary prophylaxis for pyrexia is best studied in a prospective trial.

Expression of cancer-testis antigens (MAGE-A1, MAGE-A3/6, MAGE-A4, MAGE-C1 and NY-ESO-1) in primary human uveal and conjunctival melanoma.

AIM: Metastatic disease in ocular melanoma remains untreatable, is associated with late detection and is resistant to conventional systemic therapies. Many tumours including cutaneous melanoma express specific cancer-testis (CT) antigens and vaccines targeting these antigens can induce T-cell-mediated and humoural immune responses. The authors examined primary uveal and conjunctival melanomas for expression of CT antigens to assess their potential as targets for ocular melanoma immunotherapy. METHODS: Paraffin-embedded uveal (n=32) and conjunctival (n=15) melanomas were assessed by immunohistochemistry for melanocyte differentiation antigens (gp100, Melan-A/MART-1 and tyrosinase), and CT antigens (MAGE-A1, MAGE-A3/6, MAGE-A4, MAGE-C1 and NY-ESO-1). RESULTS: Melanoma differentiation antigens, gp100, Melan-A/MART1 and tyrosinase, were expressed in >75% of tumour cells in all uveal and conjunctival melanomas tested. Expression of all five CT antigens tested was low in uveal melanomas, and when present, stained <25% of the tumour cells. MAGE-A1, MAGE-A4 and NY-ESO-1 were expressed in <10% of tumour cells in conjunctival melanomas, while MAGE-C1 and MAGE-A3/6 were expressed in ∼20% and ∼35% of tumour cells in this malignancy, respectively, with variable expression levels. CONCLUSIONS: Uveal and conjunctival melanomas consistently expressed high levels of the differentiation antigens (gp100, Melan-A/MART1 and tyrosinase). However, compared with other tumours, including cutaneous melanoma, only low levels of CT antigens were found in ocular melanomas. These observations suggest that immunotherapy directly targeting the CT antigens studied may not be effective for ocular melanoma.

Fourier transform infrared imaging as a method for detection of HLA class I expression in melanoma without the use of antibody.

Human leukocyte antigen (HLA) class I expression in melanoma is usually assessed using immunohistochemical staining. Here we report on the use of Fourier transform infrared (FTIR) hyperspectral imaging, a method widely used in two-dimensional analysis of chemical components, to study HLA class I expression in tissue. Two-dimensional cluster colour images derived from unsupervised hierarchical cluster analysis of FTIR hyperspectral data on melanoma sections were compared with consecutive sections that were immunohistochemically stained for class I expression. HLA-class-I-positive and -negative areas were differentiated by FTIR cluster images in all eight melanoma sections investigated without the need for antibody attachment. FTIR imaging enables the distinction of HLA-class-I-positive from class-I-negative areas in melanoma. This method is accurate, rapid and cost-effective.

Somatostatin receptor expression, tumour response, and quality of life in patients with advanced hepatocellular carcinoma treated with long-acting octreotide.

Octreotide may extend survival in hepatocellular carcinoma (HCC). Forty-one per cent of HCCs have high-affinity somatostatin receptors. We aimed to determine the feasibility, safety, and activity of long-acting octreotide in advanced HCC; to identify the best method for assessing somatostatin receptor expression; to relate receptor expression to clinical outcomes; and to evaluate toxicity. Sixty-three patients with advanced HCC received intramuscular long-acting octreotide 20 mg monthly until progression or toxicity. Median age was 67 years (range 28-81 years), male 81%, Child-Pugh A 83%, and B 17%. The aetiologies of chronic liver disease were alcohol (22%), viral hepatitis (44%), and haemochromatosis (6%). Prior treatments for HCC included surgery (8%), chemotherapy (2%), local ablation (11%), and chemoembolisation (6%). One patient had an objective partial tumour response (2%, 95% CI 0-9%). Serum alpha-fetoprotein levels decreased more than 50% in four (6%). Median survival was 8 months. Thirty four of 61 patients (56%) had receptor expression detected by scintigraphy; no clear relationship with clinical outcomes was identified. There were few grade 3 or 4 toxicities: hyperglycaemia (8%), hypoglycaemia (2%), diarrhoea (5%), and anorexia (2%). Patients reported improvements in some symptoms, but no major changes in quality of life were detected. Long-acting octreotide is safe in advanced HCC. We found little evidence of anticancer activity. A definitive randomised trial would identify whether patients benefit from this treatment in other ways.

Recombinant NY-ESO-1 cancer antigen: production and purification under cGMP conditions.

The cancer-testis antigen, NY-ESO-1, has been engineered into a bacterial expression plasmid which incorporates a His6-tag. The plasmid was transfected into E. coli strain BL21 and Master and Working cell banks generated from this expression system. Three 15-litre fermentations were performed under cGMP (code of Good Manufacturing Practice) conditions and the crude NY-ESO-1 tagged protein isolated as solubilised inclusion bodies. A three-step cGMP chromatography process (immobilised metal affinity, anion exchange, and hydrophobic interaction) was utilised to purify the protein. The purified NY-ESO-1 is being used in early stage human cancer vaccine trials in Australia and the U.S.A.

A phase II study of escalated-dose docetaxel with granulocyte colony-stimulating factor support in patients with advanced breast cancer.

PURPOSE: Docetaxel is highly active in the treatment of patients with breast cancer. The principal dose-limiting toxicities of the 3-weekly regimen are neutropenia and febrile neutropenia. In a previous phase I dose-escalation study with granulocyte colony-stimulating factor (G-CSF) support, the recommended dose was determined to be docetaxel 160 mg/m(2) 3-weekly. The objectives of this phase II study were to determine the response rate and toxicity of this dose and schedule, given as first-line in patients with advanced breast cancer. Mobilisation of peripheral blood stem cells (PBSCs) was also investigated. PATIENTS AND METHODS: Eligible women had metastatic breast cancer and were aged 18-75 years with ECOG performance status < or =2. Strict criteria for liver function were followed, and adjuvant chemotherapy must have been completed at least 6 months previously. Treatment was docetaxel 160 mg/m(2) over 60-90 min every 21 days with G-CSF 5 micro g/kg/day until neutrophil recovery, for up to six cycles. A 3-day corticosteroid prophylaxis was given. Bloods samples to determine PBSC levels [CD34+, granulocyte-macrophage colony-forming cells (GM-CFC) and burst-forming units-erythroid (BFU-E)] were taken on days 6, 8, 9 and 11 following docetaxel. RESULTS: Twenty-five women with median age 50 years (range 35-66) were included. Seventeen (68%) had previously received adjuvant chemotherapy. In total, 112 cycles were delivered (median four per patient), with dose reductions required in 12.5% of cycles. G-CSF was given for a median of 6 days. The median neutrophil nadir was 0.5 x 10(9)/l and occurred a median 5 days after treatment. The median duration of grade 3 or 4 neutropenia was 2 days (range 1-7). Grade 4 neutropenia occurred in 44% of patients, but there was only one episode of febrile neutropenia. Five patients were taken off study due to toxicities that included oedema, neurosensory toxicity and asthenia. Confirmed partial response was seen in nine patients (37.5%; 95% confidence interval 19% to 59%). CD34+ cells, GM-CFC and BFU-E levels peaked at day 8 following docetaxel administration. The median CD34+ cell peak was 6.5 x 10(4)/ml, with only 20% of patients <2 x 10(4)/ml, a level below which leukapheresis is not usually attempted. CONCLUSIONS: Docetaxel 160 mg/m(2) was delivered with G-CSF support with a very low rate of febrile neutropenia. Non-haematological toxicity was significant, causing five patients to go off study. Effective mobilisation of PBSCs was seen. The response rate of 37.5% was less than that obtained in first-line studies using standard-dose docetaxel 100 mg/m(2), suggesting that there is no additional benefit in dose escalation of this cytotoxic agent in breast cancer patients using this schedule.

A phase I dose-escalation study of docetaxel with granulocyte colony-stimulating factor support in patients with solid tumours.

BACKGROUND: Docetaxel is a widely active cytotoxic agent. The principal dose-limiting toxicities (DLTs) of the 3-weekly regimen are neutropenia and febrile neutropenia. Use of prophylactic granulocyte colony-stimulating factor (G-CSF) may allow higher doses of docetaxel to be administered with potentially greater anticancer efficacy. The objectives of this study were to determine the maximum tolerated dose (MTD) and toxicity profile of docetaxel given with G-CSF support. PATIENTS AND METHODS: Eligible patients had solid tumours and were aged 18-75 years with a WHO performance status of up to 2. Strict criteria for liver function were followed. Patients may have received one previous regimen of chemotherapy in addition to adjuvant chemotherapy. Cohorts of three to six patients received docetaxel over 60-90 min every 3 weeks, commencing at 110 mg/m(2) and escalating at 10 mg/m(2) increments. Patients also received G-CSF 5 micro g/kg/day until neutrophil recovery. A 3-day corticosteroid prophylaxis was given. RESULTS: Twenty-nine patients with median age 55 years (range 29-75) were included. Fourteen (48%) had previously received chemotherapy. At the 170 mg/m(2) dose level (the MTD), two of three patients had DLTs and 160 mg/m(2) was determined to be the recommended dose. The principal DLTs were skin and neurosensory toxicity. Asthenia was frequent, especially at dose levels >/=140 mg/m(2). Grade 4 neutropenia occurred in only 10 patients (35%) and was not dose related, with febrile neutropenia in three patients (10%). CONCLUSIONS: Docetaxel may be escalated considerably above standard doses when administered with G-CSF support. The recommended dose for phase II studies is 160 mg/m(2). With escalated-dose docetaxel, DLTs were non-haematological and qualitatively similar to the toxicity profile at standard doses.

Cancer testis antigens expression in mesothelioma: role of DNA methylation and bioimmunotherapeutic implications.

Recent evidences suggest that malignant mesothelioma may be sensitive to immunotherapy; however, little is known about malignant mesothelioma-associated tumour antigens. Focusing on cancer/testis antigens, the expression of well-characterised immunogenic tumour-associated antigens was investigated in malignant mesothelioma cells. At variance with MAGE-4 and NY-ESO-1, malignant mesothelioma cells frequently expressed MAGE-1, -2 and -3, GAGE 1-2, GAGE 1-6, SSX-2 and SSX 1-5, and distinct malignant mesothelioma cells concomitantly expressed at least four cancer/testis antigens. Additionally, the tumour-associated antigens RAGE-1 was expressed at high levels in both benign and malignant mesothelial cells. Lastly, treatment with the DNA hypomethylating agent 5-aza-2'-deoxycytidine induced and up-regulated the expression of the cancer/testis antigen examined in malignant mesothelioma cells. Overall, these findings strongly suggest that cancer/testis antigens-based immunotherapy may represent a suitable therapeutic approach to malignant mesothelioma, and foresee the clinical use of 5-aza-2'-deoxycytidine to design new chemo-immunotherapeutic strategies in malignant mesothelioma patients.

Specific targeting, biodistribution, and lack of immunogenicity of chimeric anti-GD3 monoclonal antibody KM871 in patients with metastatic melanoma: results of a phase I trial.

PURPOSE: KM871 is a chimeric monoclonal antibody against the ganglioside antigen GD3, which is highly expressed on melanoma cells. We conducted an open-label, dose escalation phase I trial of KM871 in patients with metastatic melanoma. PATIENTS AND METHODS: Seventeen patients were entered onto one of five dose levels (1, 5, 10, 20, and 40 mg/m2). Patients received three infusions of KM871 at 2-week intervals, with the first infusion of KM871 trace-labeled with indium-111 (111In) to enable assessment of biodistribution in vivo. Biopsies of metastatic melanoma sites were performed on days 7 to 10. RESULTS: Fifteen of 17 patients completed a cycle of three infusions of KM871. No dose-limiting toxicity was observed during the trial; the maximum-tolerated dose was therefore not reached. Three patients (at the 1-, 5-, and 40-mg/m2 dose levels) developed pain and/or erythema at tumor sites consistent with an inflammatory response. No normal tissue uptake of 111In-KM871 was observed, and tumor uptake of 111In-KM871 was observed in all lesions greater than 1.5 cm (tumor biopsy 111KM871 uptake results: range, 0.001% to 0.026% injected dose/g). The ratio of maximum tumor to normal tissue was 15:1. Pharmacokinetic analysis revealed a 111In-KM871 terminal half-life of 7.68 +/- 2.94 days. One patient had a clinical partial response that lasted 11 months. There was no serologic evidence of human antichimeric antibody in any patient, including one patient who received 16 infusions over a 12-month period. CONCLUSION: This study is the first to demonstrate the biodistribution and specific targeting of an anti-GD3 antibody to metastatic melanoma in patients. The long half-life and lack of immunogenicity of KM871 makes this antibody an attractive potential therapy for patients with metastatic melanoma.

Exogenous peptides presented by transporter associated with antigen processing (TAP)-deficient and TAP-competent cells: intracellular loading and kinetics of presentation.

This study investigates the differential capacity of TAP-deficient T2 cells, TAP-competent EBV cells, and immature and mature dendritic cells to present peptides to preformed CTL lines. It demonstrates that presentation of exogenous peptides involves peptide uptake and loading onto newly synthesized MHC class I molecules. This mechanism was best demonstrated for low affinity peptides in the presence of irrelevant peptides competing for HLA binding sites. Under these circumstances, inhibition of protein synthesis with cycloheximide or vesicular trafficking with brefeldin A significantly reduced the presentation of low affinity peptides. This was not restored by adding exogenous beta(2)-microglobulin to stabilize the MHC complex on the cell surface. In contrast, presentation of high affinity peptides was not sensitive to cycloheximide or brefeldin A, which suggests that different mechanisms may operate for presentation of high and low affinity peptides by TAP-competent cells. High affinity peptides can apparently compete with peptides in preloaded MHC class I molecules at the cell surface, whereas low affinity peptides require empty MHC molecules within cells. Accordingly, very high concentrations of exogenous low affinity peptides in conjunction with active MHC class I metabolism were required to allow successful presentation against a background of competing intracellular high affinity peptides in TAP-competent cells. These findings have implications for the design of peptide and protein-based vaccines.

The use of dendritic cells in cancer therapy.

Although the immune system evolved to protect the host from infection, what fires the popular imagination is its potential to recognise and destroy cancer. The immune system can generate potent cytotoxicity (eg transplant rejection), but can these mechanisms be harnessed for therapeutic benefit in patients with cancer? The discovery of an ever-increasing array of tumour antigens shows clearly that the targets exist. The challenge lies in generating a sufficiently potent response towards them. Central to the processes of antigen recognition, processing, and presentation to the immune system are dendritic cells. Understanding of the relation between these and the cellular immune response is crucial to elucidation of how to manipulate immune responses. The past 20 years have witnessed a dramatic expansion in this understanding and led to the first early-phase clinical trials of dendritic cells for the treatment of cancer. These studies have established the safety and feasibility of this approach and have produced encouraging evidence of therapeutic efficacy. This paper reviews the biology of dendritic cells and their use in clinical trials, as well as highlighting issues for future trial design.

Hepatocellular carcinoma and chemoembolization.

BACKGROUND: Chemoembolization is often used in the treatment of hepatocellular carcinoma; however, there are limited data on its efficacy in an Australian setting. AIMS: To review retrospectively the experience of 21 patients with hepatocellular carcinoma who collectively had 36 chemoembolizations performed between October 1995 and February 1999 in a teaching hospital and liver transplant centre in Victoria. METHODS: Selective catheterization of the right or left hepatic arteries was performed. A mixture of cisplatin 50 mg, epirubicin 50 mg, mitomycin C 10 mg, Lipiodol and gelfoam was injected. Computed tomography (CT) scans were performed at baseline and at 1-3 months after chemoembolization. Outcome measures included response rates, toxicity, progression-free and overall survival. RESULTS: CT response rates: partial response 19% (n = 7), median duration 11 months (range 2+ to 37+); minor response 17% (n = 6), median duration 7 months (1+ to 12+); stable disease 42% (n = 15), median duration 3 months (1+ to 15 months); and progressive disease 22% (n = 8). Major toxicities included one case each of acute renal failure, contrast encephalopathy, gastric ulceration and hepatorenal failure. Median progression-free survival was 3 months (range 0-37+). Median overall survival was 15 months (range 6-50+). CONCLUSION: Chemoembolization has a role in the palliative treatment of hepatocellular carcinoma. Our response rates and toxicity data are consistent with those in the published literature. However, new treatments are needed and prevention of disease by reduction in the prevalence of chronic hepatitis B and C will be required to significantly reduce mortality from this tumour.

Plasma granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor levels in critical illness including sepsis and septic shock: relation to disease severity, multiple organ dysfunction, and mortality.

OBJECTIVE: To define the circulating levels of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) during critical illness and to determine their relationship to the severity of illness as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II score, the development of multiple organ dysfunction, or mortality. DESIGN: Prospective cohort study. SETTING: University hospital intensive care unit. PATIENTS: A total of 82 critically ill adult patients in four clinically defined groups, namely septic shock (n = 29), sepsis without shock (n = 17), shock without sepsis (n = 22), and nonseptic, nonshock controls (n = 14). INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: During day 1 of septic shock, peak plasma levels of G-CSF, interleukin (IL)-6, and leukemia inhibitory factor (LIF), but not GM-CSF, were greater than in sepsis or shock alone (p < .001), and were correlated among themselves (rs = 0.44-0.77; p < .02) and with the APACHE II score (rs = 0.25-0.40; p = .03 to .18). G-CSF, IL-6, and UF, and sepsis, shock, septic shock, and APACHE II scores were strongly associated with organ dysfunction or 5-day mortality by univariate analysis. However, multiple logistic regression analysis showed that only septic shock remained significantly associated with organ dysfunction and only APACHE II scores and shock with 5-day mortality. Similarly, peak G-CSF, IL-6, and LIF were poorly predictive of 30-day mortality. CONCLUSIONS: Plasma levels of G-CSF, IL-6, and LIF are greatly elevated in critical illness, including septic shock, and are correlated with one another and with the severity of illness. However, they are not independently predictive of mortality, or the development of multiple organ dysfunction. GM-CSF was rarely elevated, suggesting different roles for G-CSF and GM-CSF in human septic shock.

Enhancement of platelet recovery after myelosuppressive chemotherapy by recombinant human megakaryocyte growth and development factor in patients with advanced cancer.

PURPOSE: To explore the influence of dose and schedule on the ability of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) to abrogate thrombocytopenia after multiple cycles of chemotherapy and to mobilize peripheral-blood progenitor cells (PBPC). PATIENTS AND METHODS: In this open-label study, 68 patients with advanced cancer were randomized to receive PEG-rHuMGDF subcutaneously at different doses and durations before administration of carboplatin 600 mg/m(2), cyclophosphamide 1,200 mg/m(2), and filgrastim 5 microgram/kg/d. PEG-rHuMGDF was not given after the first cycle of chemotherapy but was given after the second and subsequent cycles. Chemotherapy was given every 28 days for up to six cycles. RESULTS: In patients who received the same dose of chemotherapy for at least two cycles, the platelet nadir was significantly higher (47.5 x 10(9)/L v 35.5 x 10(9)/L; P =.003) and duration of grade 3 or 4 thrombocytopenia significantly shorter (0 v 3 days; P =.004) when PEG-rHuMGDF was administered after chemotherapy. There was no evidence of an effect of PEG-rHuMGDF when it was given before chemotherapy. Platelet recovery after the first cycle of chemotherapy was no different for different PEG-rHuMGDF regimens, and there was no difference between patients treated with PEG-rHuMGDF and historical controls treated with identical chemotherapy. There was a modest dose-related increase in progenitor cell levels after administration of PEG-rHuMGDF alone. Peak levels of PBPC occurred later in cycle 2 than in cycle 1 but were not different in magnitude. CONCLUSION: PEG-rHuMGDF abrogated severe thrombocytopenia after dose-intensive chemotherapy. However, it had only a modest effect on progenitor cell levels and did not enhance progenitor cell mobilization after chemotherapy and filgrastim.

MAGE-12 and MAGE-6 are frequently expressed in malignant melanoma.

MAGE proteins have been identified as potential specific targets for cancer vaccination. Although MAGE-6 and MAGE-12 were originally identified in malignant melanoma there are no studies reporting the frequency of expression of these antigens in this malignancy. These are of relevance particularly for MAGE-6 as recent studies have identified CTL activity against several epitopes. We have studied MAGE-1, -2, -3, -4, -6 and -12 gene expression using reverse transcription-polymerase chain reaction in 47 melanoma samples and 11 melanoma cell lines established from these tumours. The tumour samples expressed MAGE-12 (74%) and MAGE-6 (64%) mRNA at much higher frequencies than the other MAGE genes. MAGE-12 and MAGE-6 were expressed at the highest frequencies, relative to the other MAGE antigens, in early stage lesions. The frequency of expression of all the MAGE genes was found to be higher in samples from metastatic deposits compared to those from locoregional disease. The cell lines all expressed the same or more MAGE antigens than the tumours from which they were derived. In only one cell line was expression of a MAGE antigen lost. Certain recurring patterns of MAGE expression were observed in the tumour samples. MAGE-6 and/or -12 expression were detected in all of those 26 tumour samples that were positive for one or more of MAGE-1, -2, -3 and -4. Twenty of these 26 samples expressed both antigens. These findings suggest that protocols targeting MAGE-12 and -6 would permit many more patients to be included into clinical cancer vaccination trials.

A phase I and pharmacokinetic study of subcutaneously-administered recombinant human interleukin-4 (rhuIL-4) in patients with advanced cancer.

PURPOSE: To investigate the pharmacokinetics and tolerability of recombinant human interleukin-4 (rhuIL-4), administered by daily subcutaneous injection, in patients with advanced cancer. PATIENTS AND METHODS: Fourteen patients with advanced cancer treated with rhuIL-4 at escalating dose levels of 0.25, 1.0 and 5.0 microg/kg/day, on days 1, 8-17, and 28-57. The primary endpoints of the study were toxicity of rhuIL-4 and the determination of the pharmacokinetics of rhuIL-4 when given by subcutaneous injection. Secondary endpoints included effects on blood counts, hematopoietic cell precursors, and various immunologic parameters. RESULTS: rhuIL-4 was well tolerated at all three dose levels. Detectable serum levels of IL-4 were found in patients at the 1.0 and 5.0 microg/kg/day dose levels. Peak serum IL-4 levels were achieved about 2 h after injection and IL-4 was still detectable 8 h after injection. No grade 4 toxicities were observed and grade 3 toxicities were confined to fever, headache and raised hepatic alkaline phosphatase. No consistent hematological or immunologic effects were observed. Although therapeutic efficacy was not an endpoint, one complete response (Hodgkin's disease) was observed. One patient with chronic lymphocytic leukemia progressed on therapy. CONCLUSION: rhuIL-4 up to 5.0 microg/kg/day is well tolerated when given by subcutaneous injection. Biologically relevant serum IL-4 levels can be achieved and sustained for at least 8 h after a single injection.

A direct comparison of cytolytic T-lymphocyte responses to Melan-A peptides in vitro: differential immunogenicity of Melan-A27-35 and Melan-A26-35.

In this study we directly compared the in vitro responses of T-cells from normal donors and melanoma patients to Melan-A27-35 and Melan-A26-35. These peptides have been previously used in peptide-based vaccination studies. Following three stimulations with peptide-pulsed antigen-presenting cells in vitro, Melan-A-specific cytolytic T-lymphocytes (CTLs) were generated from seven of 20 subjects; two of the seven subjects responded reproducibly to both Melan-A27-35 and Melan-A26-35, three to only Melan-A27-35 and two to only Melan-A26-35. However, CTLs generated with either Melan-A27-35 or Melan-A26-35 showed cross recognition, and both types of CTL could recognize naturally processed antigen displayed on HLA-A2+ tumour cells. Furthermore, Melan-A-specific CTLs could also be generated by stimulating peripheral blood mononuclear cells with autologous melanoma cells. Our results suggest that some subjects may have a bias in their CTL repertoire which favours the generation of Melan-A27-35 specific CTLs, while others may favour Melan-A26-35 specific CTLs. It is also likely that CTL precursors capable of detecting both peptides may have different affinities to the two Melan-A peptides. Since it is difficult to predict the CTL responses to Melan-A peptide in a given individual, we suggest vaccinating with both Melan-A27-35 and Melan-A26-35 peptides in clinical trials.