Impact of anti-thymocyte globulin dose for graft-versus-host disease prophylaxis in allogeneic hematopoietic cell transplantation from matched unrelated donors: a multicenter experience.

Despite the widespread use of rabbit anti-thymocyte globulin (ATG) to prevent acute and chronic graft-versus-host disease (aGVHD, cGVHD) after allogeneic hematopoietic cell transplantation (allo-HCT), convincing evidence about an optimal dose is lacking. We retrospectively evaluated the clinical impact of two different ATG doses (5 vs 6-7.5 mg/kg) in 395 adult patients undergoing HSCT from matched unrelated donors (MUD) at 3 Italian centers. Cumulative incidence of aGVHD and moderate-severe cGVHD did not differ in the 2 groups. We observed a trend toward prolonged overall survival (OS) and disease-free survival (DFS) with lower ATG dose (5-year OS and DFS 56.6% vs. 46.3%, p=0.052, and 46.8% vs. 38.6%, p=0.051, respectively) and no differences in relapse incidence and non-relapse mortality. However, a significantly increased infection-related mortality (IRM) was observed in patients who received a higher ATG dose (16.7% vs. 8.8% in the lower ATG group, p=0.019). Besides, graft and relapse-free survival (GRFS) was superior in the lower ATG group (5-year GRFS 43.1% vs. 32.4%, p=0.014). The negative impact of higher ATG dose on IRM and GRFS was confirmed by multivariate analysis. Our results suggest that ATG doses higher than 5 mg/kg are not required for MUD allo-HCT and seem associated with worse outcomes.

Efficacy of a combination of human recombinant erythropoietin + 13-cis-retinoic acid and dihydroxylated vitamin D3 to improve moderate to severe anaemia in low/intermediate risk myelodysplastic syndromes.

The efficacy of human recombinant erythropoietin (rEPO) in myelodysplastic syndromes (MDS) has generally been best in untransfused patients with 'refractory anaemia' according to the World Health Organization (WHO). We treated 63 MDS patients [excluding refractory anaemia with excess blasts, type 2 (RAEB2)] with a previously tested combination of 13-cis-retinoic acid and dihydroxylated vitamin D3 +/- 6-thioguanine in addition to rEPO. Most patients were categorized as refractory cytopenia with multilineage dysplasia and RAEB1, with intermediate 1 International Prognostic Scoring System (IPSS) score; all had Hb <95 g/l, and 70% required regular erythrocyte transfusions. Treatment was well tolerated, and erythroid response rate according to new International Working Group criteria was 60%: 50% in RAEB1 and 64% in non-RAEB patients (P = 0.383). Response rate was not affected by transfusion requirement (63%; 58% in untransfused), IPSS and WHO Prognostic Scoring System scores, and weekly rEPO dosage (30-50 000 U vs. 80 000 U). Median response duration was 16 months. Median survival reached 14 months for RAEB1 and 55 months for non-RAEB patients, with a significant difference in the latter between responders and non-responders (median 82 months vs. 44 months; P = 0.036). Our combined therapy, independent of rEPO dosage, achieved in patients with unfavourable response predictors, a rate of anaemia improvement comparable to the best obtained in lower risk patients by high-dose rEPO.