At the 50th Annual Meeting of the EBMT in Glasgow, Scotland, Florent Malard, MD, PhD, a Professor of Hematology at Sorbonne University and Saint-Antoine Hospital, Paris, France, provided critical insights into the modern landscape of graft-versus-host disease (GVHD) prophylaxis. He emphasized that the era of post-transplant cyclophosphamide (PTCy) demands a highly individualized approach, with donor type being the primary determinant for strategy selection.
Professor Malard explained that for haploidentical and mismatched unrelated donor transplants, PTCy-based regimens are now the recommended standard due to superior outcomes. However, the decision is more nuanced for matched related and unrelated donors. While some studies show PTCy is better than traditional calcineurin inhibitor-based prophylaxis, he noted that randomized trials comparing PTCy to ATG-based regimens have shown very similar outcomes. This finding supports current EBMT recommendations, which permit the use of either PTCy or ATG in this patient population.
Discussing regimen optimization, Dr. Malard highlighted specific clinical scenarios for different PTCy strategies. For patients at higher risk of acute GVHD, such as those receiving myeloablative conditioning with peripheral blood stem cells, combining PTCy with ATG may be beneficial. Conversely, for non-myeloablative platforms, PTCy monotherapy remains the optimal choice. He also touched upon the promising, though not yet fully validated, use of reduced-dose PTCy for high-risk patients, such as older adults or those with cardiac comorbidities, noting a French randomized trial is planned to confirm its efficacy and safety.
Looking ahead, Professor Malard identified dose optimization and novel combinations as key future directions. He also shared exciting preliminary work on microbiota therapy, where fecal microbiota transfer appears to reduce the risk of both GVHD and infectious complications, offering a potential new frontier in improving patient outcomes.
