Baseline characteristics of patients in our study who did and did not receive PTCy as GVHD prophylaxis
| Characteristic | No (%) | P value* | ||
| All patients, n=21 | PTCy, n=12 | No PTCy, n=9 | ||
| Median age at alloHCT (range) | 54 years (29–75 years) | 53 years (29–75 years) | 57 years (42–68 years) | 0.7 |
| Sex | 0.9 | |||
| Male | 14 (67) | 7 (58) | 7 (78) | |
| Female | 7 (33) | 5 (42) | 2 (22) | |
| Disease type | 0.9 | |||
| AML | 16 (76) | 9 (75) | 7 (78) | |
| MDS | 5 (24) | 3 (25) | 2 (22) | |
| ICI | 0.3 | |||
| Nivolumab | 16 (76) | 8 (67) | 8 (89) | |
| Ipilimumab | 5 (24) | 4 (33) | 1 (11) | |
| Median interval between alloHCT and ICI therapy initiation (range) | 9.7 months (1.3–134.4 months) | 5.1 months (1.8–57 months) | 26.6 months (5.5–134 months) | 0.04 |
| Median interval between post-alloHCT relapse and ICI therapy initiation | 2.4 months (0.1–16.4 months) | 2 months (0.2–16.4 months) | 4.7 months (0.1–14.6 months) | 0.3 |
| Hematopoietic stem cell source | ||||
| PBSCs | 14 (67) | 7 (58) | 7 (78) | 0.3 |
| BM | 7 (33) | 5 (42) | 2 (22) | |
| Donor type | ||||
| Matched related | 9 (43) | 5 (42) | 4 (44) | |
| Matched unrelated | 9 (43) | 5 (42) | 4 (44) | 1.0 |
| Haploidentical | 3 (14) | 2 (17) | 1 (12) | |
| Donor/recipient CMV status† | ||||
| R/R | 8 (40) | 3 (25) | 5 (63) | |
| R/NR or NR/R | 10 (50) | 7 (58) | 3 (38) | 0.3 |
| NR/NR | 2 (10) | 2 (17) | 0 (0) | |
| Conditioning regimen | 0.18 | |||
| Myeloablative | 15 (72) | 7 (58) | 8 (89) | |
| Non-myeloablative | 6 (28) | 5 (42) | 1 (11) | |
| Hematopoietic cell transplantation–specific comorbidity index‡ | ||||
| 0 | 3 (16) | 3 (27) | 0 (0) | |
| 1–2 | 10 (53) | 7 (64) | 3 (38) | 0.04 |
| >2 | 6 (32) | 1 (9) | 5 (63) | |
| Prior history of GVHD before ICI initiation | ||||
| None | 16 (76) | 10 (83) | 6 (67) | 0.6 |
| Acute | 5 (24) | 2 (17) | 3 (33) | |
| Chronic | 0 (0) | 0 (0) | 0 (0) | |
*P values shown in bold represent p<0.05.
†In one patient, the donor/recipient CMV status was not reported.
‡In two patients, the hematopoietic cell transplantation-specific comorbidity index was not reported.
alloHCT, allogeneic hematopoietic stem cell transplantation; AML, acute myeloid leukemia; BM, bone marrow; CMV, cytomegalovirus; GVHD, graft-versus-host disease; ICI, immune checkpoint inhibitor; MDS, myelodysplastic syndromes; NR, non-reactive; PBSCs, peripheral blood stem cells; PTCy, post-transplantation cyclophosphamide; R, reactive.