Initial management and outcome of different strategies for treatment of AML relapse after RIC HSCT in 263 patients
| . | n . | % . | Median interval from relapse to start of treatment, d (range) . | CR rate, % . | OS at 2 years from relapse, % . | Cause of death . |
|---|---|---|---|---|---|---|
| Mild chemotherapy alone | 24/88* | 33.5 | 12 (1-46) | 17 | 6.8 ± 3 | n = 82 (78 leukemia/4 NRM) |
| Intensive chemotherapy alone | 47 | 17.9 | 10 (1-97) | 27 | 4.4 ± 3 | n = 46 (42 leukemia/4 NRM) |
| Chemotherapy followed by DLI†‡ | 48 | 18.3 | 13 (2-109) | 30 | 12.6 ± 5 | n = 39 (33 leukemia/6 NRM) |
| Chemotherapy followed by 2nd HSCT§ | 20 | 7.6 | 13 (1-69) | 56 | 42.4 ± 11 | n = 13 (8 leukemia/5 NRM) |
| DLI without prior chemotherapy (with or without 2nd HSCT)‡§‖ | 40 | 15.2 | 16.5 (1-81) | 36 | 25 ± 7 | n = 32 (27 leukemia/5 NRM) |
| 2nd HSCT without prior chemotherapy§¶ | 20 | 7.6 | 16.5 (1-99) | 41 | 15 ± 8 | n = 19 (11 leukemia/8 NRM) |
| . | n . | % . | Median interval from relapse to start of treatment, d (range) . | CR rate, % . | OS at 2 years from relapse, % . | Cause of death . |
|---|---|---|---|---|---|---|
| Mild chemotherapy alone | 24/88* | 33.5 | 12 (1-46) | 17 | 6.8 ± 3 | n = 82 (78 leukemia/4 NRM) |
| Intensive chemotherapy alone | 47 | 17.9 | 10 (1-97) | 27 | 4.4 ± 3 | n = 46 (42 leukemia/4 NRM) |
| Chemotherapy followed by DLI†‡ | 48 | 18.3 | 13 (2-109) | 30 | 12.6 ± 5 | n = 39 (33 leukemia/6 NRM) |
| Chemotherapy followed by 2nd HSCT§ | 20 | 7.6 | 13 (1-69) | 56 | 42.4 ± 11 | n = 13 (8 leukemia/5 NRM) |
| DLI without prior chemotherapy (with or without 2nd HSCT)‡§‖ | 40 | 15.2 | 16.5 (1-81) | 36 | 25 ± 7 | n = 32 (27 leukemia/5 NRM) |
| 2nd HSCT without prior chemotherapy§¶ | 20 | 7.6 | 16.5 (1-99) | 41 | 15 ± 8 | n = 19 (11 leukemia/8 NRM) |
Results cannot be compared among the treatment groups due to significant imbalances with respect to important patient characteristics.
OS indicates overall survival; DLI, donor lymphocyte infusion; PBSC, peripheral blood stem cells, NRM, non-relapse mortality; and HSCT, hematopoietic stem cell transplantation.
Because of the palliative intention of the treatment in many cases, data on the interval from relapse to treatment as well as on response were not systematically collected in patients treated with mild chemotherapy alone; hence, the data presented here are based on 24 patients only of 88 who had received mild chemotherapy alone.
DLI consisted of lymphocytes alone in 26 and lymphocytes plus PBSCs in 20 patients; cell type was missing in 2 patients. Stage at DLI was active disease (n = 26), aplasia (n = 3), CR with minimal residual disease (n = 1), CR (n = 10), and unknown (n = 8). A total of 44% received 1, 31% received between 2 and 6, and 25% received an unknown number of infusions.
Among the 88 patients receiving DLI with or without prior chemotherapy, the median number of CD3+ cells transfused were 1 × 107/kg. In patients receiving additional PBSCs, the median number of CD34+ cells was 2.48 × 106/kg.
Among the 42 patients receiving a second HSCT with or without prior chemotherapy or DLI, the same donor as for first HSCT was used in 31, whereas in 11 patients, another donor was chosen. A total of 29 patients had an HLA ID sibling, 1 had a mismatched relative, and 12 had an unrelated donor. The conditioning was myeloablative and reduced in 21 patients each. All but 1 patient received PBSCs. The small numbers did not allow for a detailed analysis of risk factors after HSCT2 or an estimate of the role of a new donor.
DLI consisted of lymphocytes alone in 28 and lymphocytes plus PBSC in 5 patients; cell type was missing in 7 patients. At the time of DLI, median percentage of blasts was 0 (range, 0-85) in PB, and 14 (range, 1-60) in BM. A total of 35% received 1, 35% received > 1, and 30% received an unknown number of infusions. An escalating dose regimen was used in 1 of 3 of patients.
At start of conditioning, median percentage of blasts was 0 (range, 0-84) in PB and 30 (range 0-90) in BM.