Session: 732. Clinical Allogeneic Transplantation: Results: Poster III
Hematology Disease Topics & Pathways:
Biological, AML, Diseases, Therapies, Clinically relevant, Myeloid Malignancies, transplantation
Methods: We retrospectively analyzed 398 patients from the EBMT registry database with the following inclusion criteria: 1) adult patient in CR1 or CR2 AML; 2) T-replete Haplo-SCT with PT-Cy; 3) no in vivo depletion using antithymocyte globulin or alemtuzumab; and 4) receiving either TBF RIC (equivalent of 2-day iv busulfan dose) or CyFluTBI NMAC regimen. We compared separately TBF vs. CyFluTBI in patients younger (n=170, 82 TBF vs. 88 CyFluTBI) and older (n=228, 141 TBF vs. 87 CyFluTBI) than 60 years.
Results: In patients younger than 60 years, the 2-year cumulative incidence of relapse (CIR) was significantly lower in the TBF group compared with the CyFluTBI group (TBF vs. CyFluTBI: 14% vs. 43%, p<0.01). No significant increase in 2-year NRM was observed (TBF vs. CyFluTBI: 22% vs. 16%, p=0.15). This led to a significantly higher 2-year leukemia-free survival (LFS) probability in the TBF group (64% vs. 41%, p=0.03). After adjustment in multivariate analysis, CyFluTBI was associated with a higher risk of relapse (hazard ratio [HR] 3.4, 95%CI [1.4-6.9], p<0.01), lower LFS (HR 1.8, 95%CI 1.1-3.0, p=0.03) and lower overall survival (OS) (HR 1.8, 95%CI 1.1-3.1, p=0.02), without significant impact of conditioning regimen on incidence of GVHD and NRM.
In patients older than 60 years, univariate analysis did not show any significant difference in outcome according to the type of conditioning regimen (2-year NRM: TBF vs. CyFluTBI: 33% vs. 25%, p=0.23; 2-year CIR: TBF vs. CyFluTBI: 23% vs. 28%, p=0.20; 2-year LFS: TBF vs. CyFluTBI: 44% vs. 47%, p=0.96). Multivariate analysis showed a significant reduction in the risk of NRM after CyFluTBI (HR 0.5, 95%CI [0.2-0.9], p=0.04), while a non-significant increase in the risk of relapse was observed (HR 1.9, 95%CI [0.8-4.2], p=0.13). Finally, there was no significant difference in LFS (HR 0.9, 95%CI [0.5-1.5], p=0.67) and OS (HR 0.9, 95%CI [0.5-1.5], p=0.67).
Conclusion: Our study suggests that in CR AML patients aged younger than 60 years, the use of TBF RIC provides better outcomes than NMAC CyFluTBI due to lower incidence of relapse, without significant increase in the risk of NRM. Conversely, it seems that older patients do not benefit from such conditioning intensification, due to a significantly higher risk of NRM after TBF RIC. Thus, in CR AML patients who will not receive a truly myeloablative regimen prior to PT-Cy Haplo-SCT, age could be used for determining the conditioning intensity from the wide variety of reduced toxicity conditioning regimens. Beyond the patient age, further prospective trials should assess patient-based parameters that may be useful for a fine tuning of conditioning intensity in a more individualized approach.
Disclosures: Labopin: Jazz Pharmaceuticals: Honoraria. Blaise: Jazz Pharmaceuticals: Honoraria. Bug: Sanofi: Other: Travel; Neovii: Other: Travel; Jazz: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel; Hexal: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; Eurocept: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel. Mohty: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Stemline: Consultancy, Honoraria, Research Funding, Speakers Bureau.
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