Clinical Research On Idarubicin Intensified BuCy2 Conditioning Regimen In Patients Undergoing Allogeneic Stem Cell Transplantation For High-risk Hematological Malignancies

Objective: To evaluate the clinical effects of Idarubicin (IDA) intensified BuCy2 (IDA-BuCy2) myeloablative conditioning regimen for patients with high-risk hematological malignancies who received allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods: Between August 2003 and December 2009, 94 consecutive patients with high-risk hematological malignancies undergoing allogeneic peripheral blood stem cell transplantation were analyzed retrospectively. Fifty-three patients received IDA intensified BuCy2 (IDA-BuCy2) conditioning regimen consisting of IDA 15 mg/m2 once daily, administered by continuous infusion on days -11 to -9, followed by busulphan (Bu), 3.2 mg/kg in divided doses daily, on days -6 to -4, and intravenous injection cyclophosphamide (Cy), 1.8 g/m2 once daily on days -3 to -2. Forty-one patients received modified Bu/Cy (BuCy2) conditioning regimen involved intravenous injection of cytarabine (2g/m2 on day -8) followed by intravenous injection of Bu (3.2 mg/kg in divided doses daily, on days -7 to -5), Cy (1.8 g/m2 on days -4 to -3) and oral Me-CCNU (250 mg/m2 on day -2). The safety of IDA, regimen-related toxicities (RRT), hematopoietic recovery, acute and chronic graft-versus-host disease (GVHD), disease relapse, 2-year overall survival (OS) and disease-free survival (DFS) were evaluated. Data analyses were performed with SPSS 16.0 statistical software. Categorical variables between the two groups were compared by theχ2 test or Fisher's exact test and continuous variables by the Mann–Whitney U test. All P-values were two-sided and P value < 0.05 was considered statistically significant.Results: Between the two groups, there were no significant differences in terms of baseline characteristics, incidence of acute or chronic GVHD or transplant-related mortality (TRM). The tolerance of IDA infusion was good, and IDA-related side effects were moderate. Higher incidences of mild to moderate oropharyngeal mucositis was observed inIDA-BuCy2 group (P=0.015). For the IDA-BuCy2 and BuCy2 groups, relapse rates were 18.9% and 39%, respectively (P=0.030), the 2-year probabilities of overall survival (OS) and disease-free survival (DFS) were 65.3% versus 46.8% (P=0.038), 63.5% versus 43.4% (P=0.025), respectively. Multivariate analysis showed that IDA-BuCy2 regimens and limited chronic GVHD were the only two factors resulting in improved survival and reduced relapse rate.Conclusion: Our retrospective study suggests that IDA intensified BuCy2 conditioning regimen(IDA-BuCy2) may improved survival and reduced relapse rate compared with BuCy2 conditioning regimen for patients with high-risk hematological malignancies. IDA-BuCy2 may substitute BuCy2 as conditioning regimen for patients with high-risk hematological malignancies. The privilege of this intensified regimen should be further confirmed on a larger number of patients and on a longer follow-up duration, and a prospective and randomized study is also needed.