Reduced-intensity allogeneic hematopoietic stem cell transplantation in metastatic colorectal cancer as a novel adoptive cell therapy approach. The European group for blood and marrow transplantation experience.

Reduced-intensity conditioning (RIC) regimens for allogeneic hematopoietic stem cell transplantation (HCT) allowed the existence of an allogeneic cell-mediated antitumor effect in metastatic colorectal cancer (mCRC) to be explored. We report on 39 patients with progressing mCRC treated with different RIC regimens in a multicenter clinical trial of the European Bone Marrow Transplantation Group. Disease status at transplant was progressive disease (PD) in 31 patients (80%), stable disease (SD) in 6 (15%), and partial response (PR) in 2 (5%).