A pilot Phase I study combining peptide-based vaccination and NGR-hTNF vessel targeting therapy in metastatic melanoma.

ABSTRACT

Administration of NGR-TNF, a tumor vessel-targeting and tumor necrosis factor α TNFα) peptide conjugate, with immunotherapy has been shown to inhibit tumor growth in mice. Thus, we planned a Phase I pilot clinical trial to assess safety, immune and clinical response of this combination treatment for advanced melanoma. NA17.A2 and MAGE-3.A1 peptides were used as vaccine. HLA-A*0201 or HLA-A*01 metastatic melanoma patients received human NGR-hTNF i.v. alternating with s.c. weekly injections of either of the peptides emulsified in Montanide. The T-cell response was assessed ex-vivo using peripheral blood mononuclear cells (PBMCs) before, during and after therapy. The serum level of chromogranin A (CgA), soluble TNF receptors (sTNFR1/2), vascular endothelial growth factor (VEGF), and MIP-1ß and MCP-1 chemokines, was determined. In 3 subjects, pre- and post-treatment tumor lesions were examined by immunohistochemistry. Clinically, chills were observed in 4 patients during NGR-hTNF infusion and erythema at vaccination site was seen in 7 patients. T-cell response against the vaccine or against other melanoma-associated antigens was detectable after treatment in 6 out of 7 tested patients. Low level or reduction of CgA and sTNFR and increase of MIP-1ß and MCP-1 were found in patients sera. In the lesions examined the immune infiltrate was scanty but macrophage number increased in post-therapy lesions. From a clinical standpoint, a long term survival (>4 months) was found in 6 out of 8 evaluable patients (4, 4, 7, 11, 23+, 25+, 25+, 29+ months). The combination of NGR-hTNF and vaccine in metastatic melanoma patients was well tolerated, often associated with an ex-vivo T cell response and long-term overall survival. These findings warrant confirmation in a larger group of patients.