Targeted anti-thymocyte globulin dosing improves transplantation outcomes

Targeted dosing of anti-thymocyte globulin was associated with a reduced risk for cytomegalovirus (CMV) reactivation in adult patients undergoing unmanipulated haploidentical haematopoietic stem-cell transplantation (HSCT). Moreover, this strategy improved early CD4+ immune reconstitution, without increasing the risk for graft-versus-host disease (GVHD).

Prof. Dai-Hong Liu (Fifth Medical Center of PLA General Hospital, Beijing, China) and colleagues designed a phase 3 study (NCT05166967) to compare a targeted anti-thymocyte globulin-dosing strategy with the standard fixed-dosing strategy in patients with haematologic cancer who underwent a first unmanipulated haploidentical HSCT (n=204) [1]. Patients were allocated 1:1 to the control group, receiving a fixed dose of 10 mg/kg anti-thymocyte globulin as part of the conditioning regimen, or to the experimental arm, receiving a targeted dose of this product based on concentration monitoring. The primary endpoint was CMV reactivation at 6 months of follow-up.

At 6 months, the cumulative incidence of CMV reactivation was 31.0% in the experimental arm and 54.9% in the control arm, reflecting a significant difference (P=0.0004). Moreover, a higher proportion of participants in the targeted-dosing group achieved GVHD-free, relapse-free survival (GRFS) at 12 months (63.4% vs 48.0%; HR 0.60; P=0.008). Finally, the cumulative incidence of CD4+ T-cell immune reconstitution at ≥100 days of follow-up was higher in the targeted-dosing group than in the fixed-dosing group (91.0% vs 72.7%; P=0.002).

“Thus, promotion of early CD4+ immune reconstitution by targeted anti-thymocyte globulin-dosing might improve outcomes of haploidentical HSCT in this patient population,” concluded Prof. Liu.

1. Dou L, et al. Targeted dosing of anti-thymocyte globulin versus fixed dosing strategy in patients undergoing unmanipulated haploidentical haematopoietic stem-cell transplantation: a randomized, multicenter, phase 3 clinical trial. S256, EHA2025 Congress, 12–15 June, Milan, Italy.

Medical writing support was provided by Robert van den Heuvel.
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Posted on 16 June 20252 September 2025