Purpose: Patients with Hodgkin lymphoma (HL) relapsing after hematopoietic stem cell transplant have limited options for long-term cure. We have shown that infused cytotoxic T cells (CTL) targeting Epstein Barr virus (EBV)-derived proteins induced complete remissions in EBV(+) HL patients. A limitation of this approach is that up to 70% of relapsed HL tumors are EBV-negative. For these patients, an alternative is to target the cancer/testis antigen MAGE-A4 present in EBV antigen-negative HL tumors. Furthermore, epigenetic modification by clinically available demethylating agents can enhance MAGE-A4 expression in previously MAGE-negative tumors.
Experimental design: We explored the feasibility of combining adoptive T cell therapy with epigenetic modification of tumor antigen expression. We further characterized MAGE-A4-specific T-cell phenotype and function, and examined the effects of the epigenetic modifying drug decitabine on these T cells.
Results: Cytotoxic T cells were generated specifically recognizing MAGE-A4 expressed by autologous HL targets and tumor cell lines. Decitabine-previously shown to increase tumor antigen expression in HL-did not compromise MAGE-A4-specific T-cell phenotype and function. In patients treated with decitabine, expanded MAGE-A4-specific T cells had a broader antitumor T cell repertoire, consistent with increased antigen stimulation in vivo.
Conclusions: Adoptive transfer of MAGE-A4-specific T cells, combined with epigenetic modifying drugs to increase expression of the protein, may improve treatment of relapsed HL.