Immunization with Melan-A peptide-pulsed peripheral blood mononuclear cells plus recombinant human interleukin-12 induces clinical activity and T-cell responses in advanced melanoma.

Published

Journal Article

PURPOSE: Preclinical studies showed that immunization with peripheral blood mononuclear cells (PBMC) loaded with tumor antigen peptides plus interleukin-12 (IL-12) induced CD8+ T-cell responses and tumor rejection. We recently determined that recombinant human (rh) IL-12 at 30 to 100 ng/kg is effective as a vaccine adjuvant in patients. A phase II study of immunization with Melan-A peptide-pulsed PBMC + rhIL-12 was conducted in 20 patients with advanced melanoma. PATIENTS AND METHODS: Patients were HLA-A2-positive and had documented Melan-A expression. Immunization was performed every 3 weeks with clinical re-evaluation every three cycles. Immune responses were measured by ELISpot assay before and after treatment and through the first three cycles, and were correlated with clinical outcome. RESULTS: Most patients had received prior therapy and had visceral metastases. Nonetheless, two patients achieved a complete response, five patients achieved a minor or mixed response, and four patients had stable disease. The median survival was 12.25 months for all patients and was not yet reached for those with a normal lactate dehydrogenase. There were no grade 3 or 4 toxicities. Measurement of specific CD8+ T-cell responses by direct ex vivo ELISpot revealed a significant increase in interferon gamma-producing T cells against Melan-A (P =.015) after vaccination, but not against an Epstein-Barr virus control peptide (P =.86). There was a correlation between the magnitude of the increase in Melan-A-specific cells and clinical response (P =.046). CONCLUSION: This immunization approach may be more straightforward than dendritic cell strategies and seems to have clinical activity that can be correlated to a biologic end point.

Full Text

Cited Authors

  • Peterson, AC; Harlin, H; Gajewski, TF

Published Date

  • June 2003

Published In

Volume / Issue

  • 21 / 12

Start / End Page

  • 2342 - 2348

PubMed ID

  • 12805336

Pubmed Central ID

  • 12805336

Electronic International Standard Serial Number (EISSN)

  • 1527-7755

International Standard Serial Number (ISSN)

  • 0732-183X

Digital Object Identifier (DOI)

  • 10.1200/jco.2003.12.144

Language

  • eng