Marie Thérèse Leccia

Analysis and characterization of antitumor T-cell response after administration of dendritic cells loaded with allogeneic tumor lysate to metastatic melanoma patients.

The primary goal of cancer vaccines is to induce CD8+ T cells specific for tumor-associated antigens (TAA) but the characterization of these cells has been difficult because of the low sensitivity of ex vivo assays. Here, we focused on TAA-specific CD8+ T-cell responses in melanoma patients after vaccination with autologous dendritic cells loaded with lysates derived from allogeneic tumor-cell lines (Lysate-DC). Out of 40 patients treated, 16 patients developed immune response to tumor-cell lysate and/or CD8+ T cells specific for differentiation and cancer-testis antigens. TAA-specific CD8+ T-cell responses were detected by interferon (IFN)-γ enzyme-linked immunospot after in vitro sensitization and were, either transient during the treatment period or delayed, that is, observed after completion of all vaccinations. We could not correlate these immune responses to clinical data as none of the patients achieved an overall objective response according to Response Evaluation Criteria in Solid Tumors criteria. Three patients were reported as stable disease and 10 patients presented evidence of antitumor activity. We found that TAA-specific T cells characterized in 4 patients produced perforin ex vivo, but no IFN-γ in enzyme-linked immunospot. Differential expression of IFN-γ and perforin was also observed for viral-specific T cells. Altogether, our results show that Lysate-DC therapy elicited tumor-specific CD8+ T cells nonlimited to human leukocyte antigen-A2+ patients, with some T cells secreting perforin ex vivo and IFN-γ only after restimulation. The differential expression of perforin and IFN-γ by antitumor and antiviral CD8+ T cells supports that the sole use of IFN-γ production to monitor T cells overlooks functional T-cell subpopulations triggered by vaccines.

Adjuvant therapy with pegylated interferon alfa-2b (36 months) versus low-dose interferon alfa-2b (18 months) in melanoma patients without macrometastatic nodes: An open-label, randomised, phase 3 European Association for Dermato-Oncology (EADO) study

AIM Both low-dose interferon (IFN) alfa-2b and pegylated interferon (Peg-IFN) alfa-2b have been shown to be superior to observation in the adjuvant treatment of melanoma without macrometastatic nodes, but have never been directly compared. Peg-IFN facilitates prolongation of treatment, which could provide additional benefit. This multicentre, open-label, randomised, phase 3 trial compared standard low-dose interferon IFN and prolonged treatment with Peg-IFN. PATIENTS AND METHODS Patients with resected melanoma ≥1.5mm thick and without clinically detectable node metastases were randomised 1:1 to treatment with IFN 3 MU subcutaneously (SC) three times weekly for 18 months or Peg-IFN 100 μg SC once weekly for 36 months. Sentinel lymph node dissection (SLND) was optional. The primary endpoint was disease-free survival (DFS). Secondary endpoints included distant metastasis-free survival (DMFS), overall survival (OS) and adverse events (AEs) grade 3-4. RESULTS Of 898 patients enrolled, 896 (443 Peg-IFN, 453 IFN) were eligible for evaluation (median follow-up 4.7 years). SLND was performed in 68.2% of patients. There were no statistical differences between the two arms for the primary outcome of DFS (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.73-1.15) or the secondary outcomes of DMFS (HR 1.02, 95% CI 0.80-1.32) and OS (HR 1.09, 95% CI 0.82-1.45). Peg-IFN was associated with higher rates of grade 3-4 AEs (47.3% versus 25.2%; p<0.0001) and discontinuations (54.3% versus 30.4%) compared with IFN. CONCLUSION This trial did not show superiority for adjuvant Peg-IFN over conventional low-dose IFN in melanoma patients without clinically detectable nodes. ClinicalTrials.gov identifier: NCT00221702.

A phase I/II study of a multivalent dendritic cell vaccine in patients with metastatic melanoma

2542 Background: Vaccination with dendritic cells (DC), designed to express tumor antigens, is considered to be a possible strategy to elicit anti-tumour immune responses. Effective vaccines that mediate clinical responses in cancer patients may require generation of broad specific cytotoxic T lymphocytes directed against multiple epitopes. Allogeneic lysates from tumor cell lines are an attractive source of antigens as they contain multiple known and unknown tumor associated antigens (TAA). Methods: This is a multicentre, randomised, blinded phase I/II study in patients (pts) with stage IV (AJCC) metastatic melanoma. Safety was the primary objective; immune response (IR) and clinical response, using RECIST criteria, were secondary objectives. Patients were randomised to receive either non matured or matured DC loaded with lysate from 3 melanoma cell lines. DC were obtained from monocytes cultured with IL-13 and GM-CSF and, as required, matured with a bacterial extract and IFN-γ. Six immunizations of ∼2.0...