An Identical Reduced Intensity Conditioning (RIC) Regimen Prior to Allogeneic (allo) Hematopoietic Stem Cell Transplantation (HSCT) in 222 Patients with Hematologic Malignancies: A Monocenter Experience

Introduction: we have treated 222 consecutive patients eligible for allo HSCT with the same RIC from June 2005 up to March 2012. We particularly studied the impact of age, donor source and of the recent disease risk index (DRI) published by Amand et al (Blood 2012)

Patients and methods: all patients were treated for hematologic malignancies and were prepared with Fludarabin (30 mg/m˛/D x 5 D, IV Busulfan (3.2 mg/Kg/D x 2 D, and rabbit antithymocyte globulin (rATG) (2.5 mg/Kg/D x 2 D). All patients received CSA from D-1 with the addition of MMF in case of MMUD as post graft immunosuppression.

Results: as for August 2012, follow-up is 24 months (4-77). Patients characteristics are presented in table 1; median age was 58 years with 45% and 30% of the patients presenting with a HCT-SCI > 2 and a high or very high DRI respectively. 50% of donors were related siblings. Analyses of outcomes are presented in table 2. Age only influenced NRM (p=0.21). Donor origin has no influence on any outcome variable. DRI influenced OS (p=0.000017) (figure 1), PFS (p=0.00045) (Figure 2), relapse (p=0.0073) and at a lesser degree NRM (p=0.056)

Table 1

*	Total
N	222
Age	58 (20-72)
HCT-SCI 0-1/2/>3	53/54/90
PS  90-100/70-80/50-60	107/108/7
AML/ALL/MDS/NHL and HD/MM/others	76/10/22/71/35/8
Disease Risk index Low/Int/High/VHigh	26/132/58/6 12%/59%/26%/3%
MRD/MUD/ MMUD	111/77/34 50%/35%/15%

Table 2

	n	2-y OS	2-y PFS	2-y RR	2-y NRM
All patients	222	64%	54%	28%	20%
Low DRI	26 (12%	92%	69%	8%	13%
Int DRI	132 (59%)	69%	56%	27%	21%
High/VHigh DRI	64 (29%)	43%	40%	38%	31%
> 58 years < 58 years	120 102	61% 67%	50% 60%	/ /	27% 16%
MRD	111	67%	53%	/	16%
MUD+ MMUD	111	60%	55%	/	28%

                                                                         

PFS

OS

High-VHigh

High-VHigh

Int

Low

Int

Low

Figure 1.                                                              Figure 2.

Conclusions: Overall results are promising. They validate the previously published DRI and indicate populations where efforts should be focused. Interestingly results are similar whatever the donor is.

* HCT-SCI: hematopoietic cell transplantation specific comorbidity index; MRD: Matched related donor; MUD: Matched unrelated donor; MMUD: Mismatched unrelated donor