Session: 732. Clinical Allogeneic Transplantation: Results: Poster III
Hematology Disease Topics & Pathways:
CRS, Adverse Events, Clinically relevant
We identified total of 271 consecutive patients with hematological malignancies who received their first PBSC haplo-HCT with PTCy-based GVHD prophylaxis at City of Hope (n=157) or Moffitt (n=114) Cancer Centers between 2014 and 2019. The median patient age at HCT was 54 years (INQ range, 37-64) for the entire cohort and 48% of the patients had HCT-CI ³3. Close to 70% of the study cohort had acute leukemia and 33% of all patients had high/very high-risk disease risk index. Myeloablative conditioning was used in 52% of the cases and 81% of all HCT recipients were CMV seropositive. The median donor age at HCT was 33 years (INQ range, 26-43). The HLA -A, -B, -C, -DRB1, -DQB1, or -DPB1 mismatch between the recipient and the donor in the GVH direction was 5/10 in 51%, 4/10 in 29% and £3/10 in 20% of cases. Offspring donors were used in 54% of the patients, sibling donors in 35%, and parent/other relative donors in 11%. Female donors to male recipients were used in only 22% of patients. The median infused CD34 dose was 5.25 x106 cells/kg (range, 2.3-22.4x106) and the CD3 dose was 2.48x108 cells/kg (range, 0.002-8.88 x108). CRS of any grade by ASTCT criteria was observed in 92% of study patients within first 7 days of HCT: 54% had grade 1, 39% grade 2, and 5.2% grade 3-4.
Infused cell doses of CD34 >5x106 cells/kg and of CD3 >2.5x108 cells/kg had no significant effect on grade 3-4 CRS. On multivariable analysis, the use of reduced-intensity conditioning (RIC) was associated with increased grade 2-4 CRS (HR = 1.6, 95% CI: 1.11.-2.33, p=0.01) and grade 3-4 CRS (HR = 14.7, 95% CI: 1.97-109.5, p=0.009) compared with the myeloablative conditioning. Donor 5/10 HLA-mismatch was also associated with increased grade 2-4 CRS (HR = 1.5, 95% CI: 1.05-2.18; p=0.03) and grade 3-4 CRS (HR = 3.50, 95% CI: 1.00-12.32; p=0.05) compared with £4/10 HLA-mismatch.
Non-relapse mortality (NRM) at day 100, and 1-year overall survival (OS) by CRS severity is shown in Figure. Comparing with the grade 0-1 CRS in multivariable analysis (Table), increase in CRS severity was associated with lower probability of neutrophil engraftment (HR = 0.9 for grade 2 and HR = 0.4 for grade 3-4; p=0.03). Increased CRS severity as compared to the grade 0-1 was also predictive of higher risks of NRM (HR = 1.6, 95% CI: 0.95-2.79 for grade 2 and HR = 6.6, 95% CI: 3.12-13.78 for grade 3-4; p<0.001), lower disease-free survival (DFS; HR = 1.3 for grade 2 and HR = 4.5 for grade 3-4; p<0.001) and lower OS (HR = 1.2 for grade 2 and HR = 4.1 for grade 3-4; p<0.001) after HCT. We observed no association between CRS severity and risk of relapse or the incidence and severity of acute GvHD after transplant.
We conclude that CRS is a common complication after PB haplo-HCT/PTCy. CRS severity is associated with post-HCT outcomes with grade 3-4 CRS associated with the highest risk of NRM and overall mortality after HCT. Infused CD34 or CD3 cell doses effect on CRS is unclear. RIC and higher degree of HLA-mismatch are predictive of higher-grade CRS. Identification of modifiable risk factors can help to mitigate the risk for serious CRS and subsequent mortality after PB haplo-HCT/PTCy.
Disclosures: Nishihori: Karyopharm: Other: Research support to institution; Novartis: Other: Research support to institution. Pidala: Syndax: Consultancy, Membership on an entity's Board of Directors or advisory committees; CTI Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Takeda: Research Funding; Janssen: Research Funding; Johnson and Johnson: Research Funding; Pharmacyclics: Research Funding; Abbvie: Research Funding; BMS: Research Funding. Nakamura: Merck: Other: advisory board meeting; Alexion: Other: Support on a meeting presentation; Kyowa-Kirin: Other: Support on a meeting presentation; Celgene: Other: Support on seminar; Magenta Therapeutics: Other: Advisory board meeting; Viracor: Consultancy; Kadmon Corporation: Other: Advisory board meeting; NapaJen Pharma: Consultancy. Al Malki: Rigel Pharma: Consultancy; Jazz Pharmacuticals, Inc: Consultancy; Neximmune: Consultancy. Bejanyan: Kiadis Pharma: Membership on an entity's Board of Directors or advisory committees.
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