Type: Oral
Session: 721. Allogeneic Transplantation: Conditioning Regimens, Engraftment, and Acute Toxicities: Optimizing Conditioning and Donor Selection in Allogeneic Stem Cell Transplantation
Hematology Disease Topics & Pathways:
Research, Lymphoid Leukemias, ALL, Clinical Research, Diseases, Registries, Lymphoid Malignancies
Therefore, we performed a retrospective analysis comparing the outcomes of ALL patients, aged 45 years and older, in first complete remission (CR1) who underwent HSCT with younger (<40 years) haploD or older (>50 years) MSD between 2012 and 2022. The major endpoints were to assess overall survival, leukemia-free survival, relapse incidence, non relapse mortality, and graft-versus-host disease-free, relapse-free survival (GRFS).
A total of 756 patients were included with a median age of 56.8 years (interquartile range [IQR], 52.1- 61.1). Follow up was longer in the oMSD group compared to the yHaploD group (3.5 years vs 2.1 years, p<0.001). hematopoietic cell transplantation-specific comorbidity Index score, Karnofsky score, gender patient and MRD status at transplantation were similar between the 2 groups. The median age of the donor was 56.3 years (IQR, 52.9-60.9) in the oMSD group versus 29 years (IQR, 22.8-34.6] in the yHaploD group. There was no difference in the intensity of the conditioning regimen between the 2 groups (p=0.4). In univariate analysis, neutrophil engraftment at 30 days was significantly higher in the oMSD group: 98% [95% CI, 96.5-98.9] versus 92% [95%, CI 86.6-95.3] for yHaplo (p<0.001). With a median follow-up of 2 years, NRM was significantly higher and relapse incidence significantly lower in the yHaplo group versus the oMSD group. Survival outcomes at 2 years were distributed as follows for oMSD and yHaplo groups, respectively: overall survival 66.2% (95% CI, 61.8-70.2) versus 65.3% (95% CI, 61.8-70.2), p=0.88; LFS 57.6% (95% CI, 53.2-61.8) versus 62.1% (95% CI, 53.2-69.7), p=0.25; relapse incidence 24.9% (95% CI, 21.2-28.7) versus 11.7% (95% CI, 7-17.8), p=0.001; non-relapse mortality 17.5% (14.3-20.9) versus 26.2% (95% CI 14.3-20.9), p=0.022; GRFS 42.6% (95% CI 38.2-46.9) versus 47.2% ( 95% CI, 38.6-55.4)180-day grade II-IV acute GVHD 24.6% (95% CI, 21.1-28.2) versus 32.1% (95% CI, 24.9-39.4), p=0.06; grade III-IV acute GVHD 8.6% (95% CI, 6.5-11.2) versus 13.2% (95% CI, 8.5-19), p=0.08; chronic GVHD of all grades 43.5% (95% CI, 39-48) versus 39.2% (95% CI, 30.7-47.7), p=0.2; extensive chronic GVHD 22.5% (95% CI, 18.8-26.4) versus 18.2% (95% CI, 11.9-25.6), p=0.15. In multivariate analysis, yHaploD was the only factor associated with lower RI (HR=0.49, 95 %CI, 0.9-2.28, p=0.008). All other outcomes including NRM, LFS, OS, and GRFS did not differ between donor types. Patient age (per 10 years) had a negative impact on LFS (HR=1.25, 95% CI, 1-1.55; p=0.047) and also on OS (HR=1.33, 95% CI, 1.06-1.69, p=0.015). In addition, the use of TBI and a female donor with a male recipient were associated with higher risk of extensive chronic GVHD (HR=1.61, 95% CI, 1.04-2.48, p=0.03 and HR=1.52, 95% CI, 1-2.31, p=0.049; respectively).
In our study, yHaploD seems to be a valid option compared to oMSD for patients undergoing HSCT for ALL in CR1. Indeed, yHaploD significantly reduces the risk of relapse and achieves similar survival outcomes compared to oMSD.
Disclosures: Kröger: Novartis, BMS, Neovii, Kite/Gilead, Sanofi, Takada: Membership on an entity's Board of Directors or advisory committees; Novartis, Neovii, Kite/Gilead, Therakos, Alexion, Sanofi, Takeda: Other: Speaker honoraria; Novartis, DKMS: Research Funding; Provirex: Consultancy. Giebel: Celgene/BMS, Janssen, Pfizer: Speakers Bureau; Miltenyi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kiadis Pharma, The Netherlands: Research Funding; Gilead/Kite: Research Funding, Speakers Bureau; Immunicum/Mendes: Membership on an entity's Board of Directors or advisory committees; Equity Ownership (Private company): Research Funding. Mohty: Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria; Pfizer: Consultancy, Current holder of stock options in a privately-held company, Honoraria, Research Funding, Speakers Bureau; Takeda: Honoraria; GSK: Honoraria; Novartis: Honoraria; Stemline Menarini: Honoraria; Jazz: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria; Adaptive: Honoraria; MaaT Pharma: Current equity holder in publicly-traded company. Ciceri: ExCellThera: Membership on an entity's Board of Directors or advisory committees.