Orca-T vs allogeneic hematopoietic stem cell transplantation (Precision-T): a multicenter, randomized phase 3 trial
Everett Meyer, Amandeep Salhotra, Arpita Gandhi, Jeremy Pantin, Sagar S. Patel, Rasmus T. Hoeg, Alexandra Gomez-Arteaga, Rawan Faramand, Roni Tamari, Edmund K. Waller, Satyajit Kosuri, Antonio Jiménez, Jennifer Holter‐Chakrabarty, Bhagirathbhai Dholaria, Yi‐Bin Chen, Betty K. Hamilton, John Magenau, Alireza Eghtedar, Joshua M. Murray, Anna Pavlova, Nathaniel B. Fernhoff, James Scott McClellan, M. Scott Killian, Li Ai, Robert S. Negrin, Caspian Oliai
Abstract
ABSTRACT: To prevent graft-versus-host disease (GVHD) in patients undergoing myeloablative allogeneic hematopoietic stem cell transplantation (alloHSCT), a calcineurin inhibitor plus methotrexate is routinely used. Early phase studies suggested improved outcomes with Orca-T, an allogeneic T-cell immunotherapy that uses purified donor regulatory T cells to prevent GVHD with significantly less immunosuppression. This phase 3 trial randomized adult patients (N = 187) with acute leukemias or myelodysplastic syndrome undergoing myeloablative conditioning to receive either Orca-T with tacrolimus or a conventional allograft with tacrolimus and methotrexate (Tac/MTX), using granulocyte colony-stimulating factor-mobilized peripheral blood from HLA-matched donors. The primary end point was survival free from moderate-to-severe chronic GVHD (cGVHD; cGFS). Using a stratified log-rank test, cGFS was significantly higher in the Orca-T arm than in Tac/MTX (hazard ratio, 0.26; 95% confidence interval, 0.14-0.47; P< .001). One-year estimates were as follows: cGFS was 78.0% with Orca-T vs 38.4% with Tac/MTX; cumulative incidence of moderate-to-severe cGVHD was 12.6% with Orca-T and 44.0% with Tac/MTX (Gray test P< .001); overall survival was 93.9% with Orca-T vs 83.1% with Tac/MTX (P = .12); GVHD-free and relapse-free survival was 63.1% and 30.9% in the Orca-T and Tac/MTX arms (P< .001), respectively; nonrelapse mortality (NRM) was 3.4% with Orca-T vs 13.2% with Tac/MTX (P = .03). Orca-T met the primary end point of improved survival free from cGVHD compared with Tac/MTX prophylaxis and should be considered a new therapeutic option with low toxicity for GVHD prophylaxis. Moreover, significantly less toxicity was observed with Orca-T patients, including fewer serious infectious complications and less NRM. This trial was registered at www.clinicaltrials.gov as NCT05316701.