Incorporation of selinexor into conditioning regimens prior to allogeneic hematopoietic stem cell transplantation: a single-center clinical study

OBJECTIVE: Clinical data on incorporating selinexor into conditioning regimens before allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain limited. We evaluated the feasibility and safety of selinexor-containing conditioning in patients with high-risk myeloid malignancies. METHODS: This retrospective single-center case series included 12 consecutive patients receiving selinexor-containing conditioning before allo-HSCT. Toxicities, engraftment, graft-versus-host disease (GVHD), relapse, non-relapse mortality (NRM), and survival were descriptively evaluated. PFS and OS were estimated using Kaplan-Meier methods; competing-risk methods were used for relapse, NRM, and GVHD; and follow-up was estimated using reverse Kaplan-Meier. RESULTS: All patients completed planned selinexor administration, with manageable toxicity and no unexpected organ toxicity. Neutrophil engraftment was achieved in all evaluable patients and platelet engraftment in the majority. Median follow-up was 42 months (95% CI, 25-42 months). Median PFS and OS were 9.0 months (95% CI, 2.0-25 months) and 10.0 months (95% CI, 2-30 months), respectively. At 12 months, the cumulative incidences of relapse and NRM were both 33.3% (95% CI, 10.3%-58.8%). Day + 100 overall aGVHD incidence was 41.7% (95% CI, 15.2%-66.5%), and 12-month overall cGVHD incidence was 25.0% (95% CI, 6.0%-50.5%). CONCLUSION: In this single-center retrospective experience, incorporation of selinexor into conditioning regimens prior to allo-HSCT was feasible and associated with manageable toxicity in in selected patients with high-risk myeloid malignancies. Given the small sample size and absence of a comparator cohort, these findings should be interpreted cautiously. Prospective studies are warranted to further define the role of selinexor in the transplant setting.