Authors: Catherine M. Bollard, Tamara Tripic, Conrad Russell Cruz, Gianpietro Dotti, Stephen Gottschalk, Vicky Torrano, Olga Dakhova, George Carrum, Carlos A. Ramos, Hao Liu, Meng-Fen Wu, Andrea N. Marcogliese, Cecilia Barese, Youli Zu, Daniel Y. Lee, Owen O’Connor, Adrian P. Gee, Malcolm K. Brenner, Helen E. Heslop, Cliona M. Rooney
Summary: Purpose: Transforming growth factor-β (TGF-β) 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-β receptor type 2 (DNRII) on the safety, survival, and activity of infused tumor-directed T cells.
Materials and Methods: In a dose escalation study, eight patients with Epstein Barr virus–positive Hodgkin lymphoma received two to 12 doses of between 2 × 107 and 1.5 × 108 cells/m2 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.
Results: DNRII-LSTs were resistant to otherwise inhibitory concentrations of TGF-β 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.
Conclusion: TGF-β–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.
Source:
Journal of Clinical Oncology; 2018, JCO.2017.74.317