Session: 721. Allogeneic Transplantation: Conditioning Regimens, Engraftment, and Acute Toxicities: Poster III
Hematology Disease Topics & Pathways:
Adverse Events
Eighty patients with various underlying diagnoses who underwent HaploHCT between October 2021 and March 2023 were enrolled. All patients received uniform GvHD prophylaxis comprising PTCy (I.V. 50 mg/kg/day x 2 days (day +3 to day +4) and i.v. Cyclosporine A (CsA) (2.5mg/kg, Q12H) with oral Mycophenolate Mofetil (MMF) (15 mg/kg/dose Q8H) from day +5 post-HCT. Baseline demographic information, clinical and laboratory data, and details of transplantation, including donor characteristics, were retrieved from the electronic medical records. The EASIXd0 score was calculated as (serum LDH (U/L) x serum creatinine (mg/dL))/platelet count (x 10^9 /L) using laboratory data recorded on the day of HCT (day 0). The calculated EASIXd0 scores were then tested to predict early TRM (Day+30), TRM (Day+100), and 1-year Overall Survival (OS).
The median patient age was 21 (1 to 59), and 53 (66.3%) were males. 53 (66.3%) patients were undergoing HaploHCT for hematological malignancies. All received peripheral blood stem cell grafts, of which 47 (58.8%) patients received myeloablative conditioning before HCT. The median EASIXd0 score was 1.14, ranging between 0.16 and 21.73. Thirteen (16.3%) patients had TRM+30, thirty-one (38.8%) patients had TRM+100 and the 1-year OS was 48.7%. The major causes of early deaths (day 30 and day 100) were Infections (61%), GvHD (13%), and regimen-related toxicities (16%). The median EASIXd0 score was significantly higher among patients with TRM+30 (4.95 vs. 0.97, p=0.01) and TRM+100 (3.12 vs. 0.93, p=0.03).
Further analysis revealed that the cumulative incidence of TRM at 30 days was 25% for the patients with above the median EASIX d0 (>1.14) score compared with 7% for those with below the median EASIX d0 score (p=0.03). Similarly, the cumulative incidence of TRM at 100 days was 52% for the patients with above the median EASIX d0 (>1.14) score compared with 25% for those with below the median EASIX d0 score (p=0.01). We then tested other risk factors, including post-HCT factors, that could impact TRM; only non-engraftment of neutrophils and platelets impacted TRM at both 30 and 100 days significantly (p<0.001). Further, regression analysis revealed that a high EASIXd0 score >1.14 was associated with high TRM+30 (HR=4.11; 95%CI=1.04-16.29; p=0.04).
Our study suggests that the EASIX d0 score can identify patients at greater risk for early TRM in patients undergoing haploHCT. Further studies are ongoing to validate our findings in a larger prospective cohort of patients undergoing HaploHCT with PTCy/CsA/MMF-based GvHD prophylaxis to test the clinical utility of EASIX d0 score as a prognostic biomarker for HaploHCT.
Disclosures: Abraham: Roche: Other: Travel Grant, Research Funding; Novo Nordisk: Honoraria, Other: Travel Grant, Research Funding. Srivastava: Regeneron: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Research Funding, Speakers Bureau; Biomarin: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; Spark: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau.