Haploidentical Transplantation Effective as Front-line Therapy for Standard-risk ALL

Haploidentical donor (HID) transplants may be therapeutically equivalent to human leucocyte antigen (HLA)-matched sibling donor (MSD) and HLA-matched unrelated donor (MUD) transplants in standard-risk patients with acute lymphoblastic leukemia (ALL) in first complete remission (CR1), according to a study published in the British Journal of Haematology.¹

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is recommended for high-risk adult patients with ALL in CR1, and evidence from previous studies suggests that patients with standard-risk ALL in CR1 could benefit from receiving HID, MSD, or MUD.

This study retrospectively assessed 348 standard-risk patients with ALL in CR1, of which 127 patients received HID, 144 received MSD, and 77 received MUD. Patients received prophylactic treatment for infection and graft-vs-host disease (GVHD).

There were no significant differences in the HID, MSD, and MUD arms in the 5-year cumulative overall survival (OS) rates (70.1%, 73.7%, and 69.8%, respectively; P = .525), the 5-year cumulative transplant related mortality (16.4%, 11.6%, and 19.6%, respectively; P = .162), and 5-year disease-free survival (68.7%, 67.3%, and 63.7%, respectively; P = .606) respectively.

No significant differences were observed in the HID, MSD, and MUD arms for grade 3 to 4 acute GVHD (aGVHD) (11.4%, 7.7%, and 13.5%, respectively; P = .468), 5-year relapse rate post-transplantation (14.8%, 21.1%, and 16.7%, respectively; P = .231), and 3-year GVHD relapse-free survival (50.8%, 54.9%, and 52.2%, respectively; P = .847) respectively.

The only significant difference among the HID, MSD, and MUD groups was observed in the cumulative incidence of grade 2 to 4 aGVHD (39.5%, 24.0%, and 40.3%, respectively; P = .020) respectively.

The authors concluded that these “results suggest the outcomes of HID transplant are equivalent to those of MSD and MUD transplants. HID transplantation might be an alternative front-line choice for standard-risk adults with ALL in CR1 who lack a matched donor.”

Reference

1. Han LJ, Wang Y, Fan ZP, et al. Haploidentical transplantation compared with matched sibling and unrelated donor transplantation for adults with standard-risk acute lymphoblastic leukaemia in first complete remission. Br J Haematol. 2017 Jul 24. doi: 10.111/bjh.14854 [Epub ahead of print]