Sequential Conditioning with Thiotepa in T Cell- Replete Hematopoietic Stem Cell Transplantation for the Treatment of Refractory Hematologic Malignancies: Comparison with Matched Related, Haplo-Mismatched, and Unrelated Donors

•Thiotepa-based sequential conditioning is safe in a haploidentical transplantation setting.•This sequential approach is efficient in patients with refractory hematologic malignancies.•Patients had better outcomes with haploidentical donors than with unrelated donors.•This study does not support the use of unrelated donors in refractory patients.•Related donors, either matched or haploidentical, should be preferred.