Tumor-Specific T-Cells Engineered To Overcome Tumor Immune Evasion Induce Clinical Responses In Patients With Relapsed Hodgkin Lymphoma

PurposeTransforming growth factor- (TGF-) production in the tumor microenvironment is a potent and ubiquitous tumor immune evasion mechanism that inhibits the expansion and function of tumor-directed responses; therefore, we conducted a clinical study to discover the effects of the forced expression of a dominant-negative TGF- receptor type 2 (DNRII) on the safety, survival, and activity of infused tumor-directed T cells.Materials and MethodsIn a dose escalation study, eight patients with Epstein Barr virus-positive Hodgkin lymphoma received two to 12 doses of between 2 x 10(7) and 1.5 x 10(8) cells/m(2) of DNRII-expressing T cells with specificity for the Epstein Barr virus-derived tumor antigens, latent membrane protein (LMP)-1 and LMP-2 (DNRII-LSTs). Lymphodepleting chemotherapy was not used before infusion.ResultsDNRII-LSTs were resistant to otherwise inhibitory concentrations of TGF- in vitro and retained their tumor antigen-specific activity. After infusion, the signal from transgenic T cells in peripheral blood increased up to 100-fold as measured by quantitative polymerase chain reaction for the transgene, with a corresponding increase in the frequency of functional LMP-specific T cells. Expansion was not associated with any acute or long-term toxicity. DNRII-LSTs persisted for up to 4 years. Four of the seven evaluable patients with active disease achieved clinical responses that were complete and ongoing in two patients at > 4 years, including in one patient who achieved only a partial response to unmodified tumor-directed T cells.ConclusionTGF--resistant tumor-specific T cells safely expand and persist in patients with Hodgkin lymphoma without lymphodepleting chemotherapy before infusion. DNRII-LSTs can induce complete responses even in patients with resistant disease. Expression of DNRII may be useful for the many other tumors that exploit this potent immune evasion mechanism.