Infusion of Melan-A/Mart-1 specific tumor-infiltrating lymphocytes enhanced relapse-free survival of melanoma patients

Abstract

Adoptive therapy of cancer has been mostly tested in advanced cancer patients using tumor-infiltrating lymphocytes (TIL). Following discouraging results likely due to poor tumor-specificity of TIL and/or high tumor burden, recent studies reiterate the enormous potential of this therapy, particularly in melanoma. We had performed a phase II/III randomised trial on 88 stage III melanoma patients, who received autologous TIL plus IL-2 or IL-2 alone, after complete tumour resection. We reported previously clinical and immunological results supporting the ability of tumor reactive TIL infusion to prevent further development of the melanoma disease and to increase overall survival of patients bearing only one tumor invaded lymph node. The absence of correlation between overall and disease-free survival and the amount of infused tumor-specific TIL suggested that therapeutic efficiency might depend on other parameters such as antigen specificity, function or persistence of TIL. Here we studied the recognition of a panel of 38 shared tumor-associated antigens (TAA) by TIL infused to the patients included in this assay, in order to determine if treatment outcome could correlate with particular antigen specificities of infused TIL. Results show that the infusion of Melan-A/MART-1 reactive TIL appears to be associated with a longer relapse-free survival for HLA-A2 patients. These results further support the relevance of Melan-A/MART-1 antigen as a prime target for immunotherapy protocols in melanoma.

Fig. 1

Recognition of tumor-associated antigens by TIL populations infused to RF-patients (a) and to R-patients (b). COS cells were transfected with a cDNA coding for an HLA molecule and a cDNA coding for an antigen. After 48 h incubation, COS cells were co-cultured 6 h at 37°C with TIL populations. Thereafter, TNF-α secreted in the supernatant was measured. Open square TNF produced by TIL populations in response to COS cells transfected with the HLA molecule alone. Shaded square responses to COS cells transfected with the HLA and a control antigen. Black shaded square responses to COS cells transfected with a recognized HLA/antigen association. Square with diagonal TNF produced by TIL populations in response to COS cells transfected with the HLA-A*0201 and Melan-A/MART-1. Asterisk patients bearing only one invaded lymph node. Inset in M212 panel illustrates a specific response to MAGE-A3/A29 of a T cell clone derived from this TIL population

Fig. 2

Distribution of antigens recognized by 8/12 TIL infused to RF-patients (a) and 13/25 R-patients (b). Encircled HLA contexts illustrated undescribed HLA/Antigen associations

Fig. 3

Relapse-free interval in 22 HLA-A2 melanoma patients treated with IL-2 and TIL containing (dashed line) or not (solid line) Melan-A specific lymphocytes. Asterisk number of RF-patients/total number of patients

Fig. 4

HLA-A2 TIL labeled with the A2/Melan-A_26–35L tetramer a RF-patients and b R-patients. TIL were coincubated for 1 h at 4°C in the dark with Melan–A tetramer (10 μg/ml) and CD8-FITC mAb (5 μg/ml). Compensation was checked before each acquisition. Events (10⁵ among CD8 positive T cells) were collected using a FACScan set on a maximal flow rate of 1,000 events/s. Asterisk melanoma patients bearing only one invaded lymph node. Patients M254 to M278 have been enrolled in the open study