Abstract 528

Acute leukemia refractory to chemotherapy is uniformly fatal without hematopoietic cell transplantation (HCT). However, the benefit of transplantation for patients not in complete remission (CR) is controversial.

PATIENTS AND METHODS:

2,255 patients transplanted (at 252 centers in 38 countries) with an allogeneic donor after myeloablative conditioning regimen between 1995 and 2004 for acute leukemia in relapse or with primary induction failure were reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). 1,673 had acute myeloid leukemia (AML) and 582 acute lymphoblastic leukemia (ALL). Median age was 38 and 29 years for AML and ALL patients, respectively. Presence of circulating blasts, >25% marrow blasts, Karnofsky score < 90 %, or transplant in first relapse was observed in nearly half of the patients (see Table).

Table
AMLALL
Characteristics at HCT n=1673 582 
> 25 % marrow blasts 47% 43% 
Circulating blasts 57% 38% 
Karnofsky < 90% 48% 47% 
Duration of CR1 < 6 months 31% – 
1st refractory or ≥ 2nd relapse – 62% 
Poor risk cytogenetics 16% 26% 
Outcomes (95% CI) 3-yrs OS 19% (17-21) 16% (13-20) 
aGVHD 3-4 23% (21-26) 27% (24-31) 
cGVHD 27% (25-30) 27% (23-32) 
AMLALL
Characteristics at HCT n=1673 582 
> 25 % marrow blasts 47% 43% 
Circulating blasts 57% 38% 
Karnofsky < 90% 48% 47% 
Duration of CR1 < 6 months 31% – 
1st refractory or ≥ 2nd relapse – 62% 
Poor risk cytogenetics 16% 26% 
Outcomes (95% CI) 3-yrs OS 19% (17-21) 16% (13-20) 
aGVHD 3-4 23% (21-26) 27% (24-31) 
cGVHD 27% (25-30) 27% (23-32) 
RESULTS:

100 day mortality was 39% in AML and 41% in ALL. The median follow-up of survivors was 5 years. Overall survival (OS) was 19% (95% confidence interval (CI) 17-21) for AML and 16% (13-20) for ALL patients. For AML patients, five adverse pre-transplant variables significantly impacted OS : first CR duration < 6 months, blasts in the blood, donor other than HLA-identical sibling or partially matched unrelated, Karnofsky score < 90%, poor-risk cytogenetics. 106 AML patients had none of these high risk criteria, with a 3 years OS of 44% (35-54). For ALL patients, survival was worse with either: 1st refractory or ' 2nd relapse, ≥ 25% marrow blasts, CMV seropositive recipient, age ≥10 years. 8 ALL patients had no high risk criteria, with a 3 years OS of 85% (53-100). Grade 3-4 acute graft-vs-host disease (GVHD) occurred in 23% of AML and 27% of ALL patients. Chronic GVHD developed in 27%. Leukemia was the cause in 42 % of AML and 37% of ALL patients' deaths.

CONCLUSIONS:

1. HCT can cure some patients with acute leukemia in relapse or with PIF, particularly those lacking defined high risk features. 2. These pre-transplant variables should be considered when deciding whether or not to offer HCT to such patients.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.

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