A cell-based immunotherapeutic product containing T-lymphocyte-enriched leukocytes that are devoid of alloreactive T-lymphocytes, that can potentially be used to restore lymphocyte levels after stem cell transplantations and are derived from partially matched (haploidentical) family donors for blood cancer patients who do not have a matching stem cell donor available. Host alloreactive T-cells, which can cause graft-versus-host disease (GVHD), are eliminated from the donor lymphocytes ex vivo using photodynamic therapy. After allogeneic hematopoietic stem cell transplantation (HSCT), allodepleted T cell immunotherapeutic ATIR101 is administered. This maintains a T-cell-mediated immune response against tumor cells and the donor T-cells can prevent opportunistic infections. ATIR101 does not cause severe, acute GVHD. In addition, administration of ATIR101 eliminates the need for immunosuppressants.