PTCy versus CNI-based GVHD prophylaxis in HLA-matched transplants for Hodgkin Lymphoma: a study of the LWP of the EBMT.

Studies comparing the efficacy of post-transplant cyclophosphamide (PTCy) to conventional calcineurin inhibitor (CNI)-based GVHD prophylaxis regimens in Hodgkin lymphoma (HL) patients are scarce. This study aimed to compare the outcomes of HL patients undergoing hematopoietic stem cell transplantation from HLA-matched donors who received GVHD prophylaxis with either PTCy or conventional CNI-based regimens, using data reported to the EBMT database between January 2015 and December 2022. Among the cohort, 270 recipients received conventional CNI-based prophylaxis and 176 received PTCy prophylaxis. Notably, PTCy prophylaxis was associated with delayed hematopoietic recovery, but also with a lower risk of chronic (25% versus 43%, p<0.001) and extensive chronic GVHD (13% versus 28% p=0.003) compared to the CNI-based cohort. The 2-year cumulative incidence of non-relapse mortality and relapse were 11% versus 17% (p=0.12), and 17% versus 30% (p=0.007) for PTCy and CNI-based, respectively. Moreover, the 2-year overall survival, progression-free survival and GVHD-free, relapse-free survival were all significantly better in the PTCy group compared with the CNI-based group: 85% versus 72% (p=0.005), 72% versus 53% (p<0.001), and 59% versus 31% (p<0.001), respectively. In multivariable analysis, PTCy was associated with a lower risk of chronic and extensive chronic GVHD, reduced relapse, and better OS, PFS, and GRFS compared to the CNI-based platform. Our findings suggest that PTCy as GVHD prophylaxis offers more favorable outcomes compared to conventional CNI-based prophylaxis in adult patients with HL undergoing HSCT from HLA-matched donors.