Recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant induces broad integrated antibody and CD4(+) and CD8(+) T cell responses in humans

Abstract

NY-ESO-1 is a "cancer-testis" antigen expressed in many cancers. ISCOMATRIX is a saponin-based adjuvant that induces antibody and T cell responses. We performed a placebo-controlled clinical trial evaluating the safety and immunogenicity of recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant. Forty-six evaluable patients with resected NY-ESO-1-positive tumors received three doses of vaccine intramuscularly at monthly intervals. The vaccine was well tolerated. We observed high-titer antibody responses, strong delayed-type hypersensitivity reactions, and circulating CD8(+) and CD4(+) T cells specific for a broad range of NY-ESO-1 epitopes, including known and previously unknown epitopes. In an unplanned analysis, vaccinated patients appeared to have superior clinical outcomes to those treated with placebo or protein alone. The vaccine is safe and highly potent immunologically.

Fig. 1.

Ab responses by treatment dose level. Each curve represents an individual pt within that dose level. y axis is reciprocal titer on a logarithmic scale. Shaded area indicates titers below the limit of quantitation (<5,000).

Fig. 2.

DTH measurements (Induration) 2 days after intradermal injection of 1 μg of NY-ESO-1 protein without IMX. Each curve represents an individual pt within that dose level. Pre, before vaccination; Post, after three vaccinations at day 86.

Fig. 3.

Time course of T cell responses. (A) CD8+ T cell responses in four HLA-A2+ pts with detectable responses against NY-ESO-1_157–165 epitope SLLMWITQC. Solid line with closed symbol indicates ICS assay (left y axis). Dashed line with open symbol indicates tetramer assay (right y axis). Shaded area indicates cutoff for positive ICS response (0.1%). (B) Induction of CD4+ T cell responses in pt 14. Filled bars, before treatment; stippled bars, after three vaccinations. (C) Induction of CD8+ and CD4+ T cell responses in pt 13. Filled bars, before treatment; stippled bars, after three vaccinations.

Fig. 4.

Peripheral blood T cell HLA class I- and II-restricted responses to overlapping 13-mer NY-ESO-1 peptides. Large bars and numbers represent the protein and amino acids of NY-ESO-1. Dark bars, HLA class I responses; light bars, HLA class II responses; filled bars, previously undescribed epitopes; striped bars, class I epitopes definitely or possibly described previously; dotted bars, class II epitopes definitely or possibly described previously; numbers in bold italics, responses proven to be induced by vaccination; underlined numbers, proven preexisting responses; numbers neither in bold italic nor underlined, unable to ascertain whether preexisting or induced. Numbers to the left indicate the pt number. 7 (DTH) to responses observed in T cells derived from a DTH injection site in pt 7. All pts shown had resected melanoma and received treatment at the 100+IMX dose level, except pt 39, who received NY-ESO-1 protein without IMX. Pts 7, 9, 21, and 39 were HLA-A2-positive, and pts 13, 14, 16, and 24 were HLA-A2-negative.

Fig. 5.

Detailed results from pt 7. Vertical axis represents percent CD8+ (Upper) or CD4+ (Lower) T cells positive for IFN-γ. Values >1.0% are represented by the numbers and arrows. Screening 13-mer peptides used in the ICS assay are listed on the x axis by the number of the first amino acid residue. Stimulating 18-mer peptides used for culturing T cells are coded by color on the y axis and cover the same regions as the 13-mers. DP4, HLA-DP4 epitope (157–170).