Program: Oral and Poster Abstracts
Session: 732. Clinical Allogeneic Transplantation: Results: Poster II
Patients and Methods:This single-center retrospective study considered MF patients with a validated indication of allo-SCT between 2000 and 2013. The main objective was to compare the overall survival (OS) between patients who ultimately received allo-SCT or not. Secondary objectives were to analyze the impact of mutational molecular status on OS and the use of ruxolitinib in patients not allografted.
Results: An indication of allo-SCT was validated in 67 patients (males: 64%; PMF: 59%; SMF post-ET 25%, SMF post-PV 16%). At the time of indication of ASCT, the median age was 59 years (range: 41-69); DIPSS+ score was: int-2 in 40%, high risk in 60%. Mutational status, available for 86% of patients, was as follows: JAK2V617F (n=37), CALRmut (n=12); MPLmut (n=3), triple-negative (n=6). Thirty-three patients proceeded to allo-SCT (reduced intensity conditioning: 82%) while 34 did not for lack of donor (31%), comorbidity (28%), progressive disease (14%), stable disease on conventional therapy (18%), refusal (9%). The two groups (allo/non-allo SCT) were comparable for gender, year of indication of allo-SCT, type of MF, number of prior lines of treatment before allo-SCT, DIPSS+ categorization, mutational status and median follow-up. Patients who did not proceed to allo-SCT were significantly older (61 vs 57 years, p<0.005). Two allografted patients received ruxolitinib after transplant while 9 patients received it after invalidation of the transplant procedure. With a median follow-up of 44 months, median OS was 57 months for the whole cohort. A significantly lower OS was associated to unfavorable karyotype (median: 17 vs 100 months, HR: 2.6, 95%CI: 1.1-6.5, p=0.02), higher percentage of circulating blasts at time of indication of SCT (HR: 1.15, 95%CI: 1.01-1.32, p=0.01) and higher DIPSS+ score (HR: 1.3, 95%CI: 1.01-1.6 p=0.01). There was a trend for a better OS in CALRmut patients compared to other patients (median not reached (NR) vs 35 months, HR: 0.63, 95%CI: 0.25-1.51, p=0,3), especially vs triple-negative patients (NR vs 15 months, HR:0.29, 95%CI: 0.09-0.9 p=0.025). Five-year OS was similar between both groups (allo: 51% vs non-allo 44%, p=ns). However, progression to myelodysplastic syndrome or acute myeloid leukemia was significantly lower for allografted patients (19.2% vs 44.5%, p=0.01). In univariate analysis, allo-SCT benefited to patients with SMF post TE/PV (median OS: allo 115 vs non-allo 18.4 months, HR: 0.18, 95%CI: 0.05-0.5, p=0.004), unfavorable karyotype (median OS: allo: NR vs non-allo 7.9 months, HR: 0.13, 95%CI: 0.04-0.4, p=0.002) or high DIPSS+ score (median OS: allo 120 vs non-allo 18 months, HR:0.41, 95%CI: 0.16-0.9, p=0.04). Also there was a trend for better OS in allografted patients with high JAK2V617Fburden (>65%) (median OS: NR vs 18 months, HR: 0.18, 95%CI:0.03 -1.11, p=0.065). Interestingly, the survival of patients who did not proceed to allo-SCT was increased by the use of ruxolitinib (median OS: NR vs 20 months, HR: 2.3, 95%CI: 0.08-0.6, p=0.003).
Conclusion: Allo-SCT remains a valid strategy for high-risk MF patients with unfavorable karyotype, high DIPSS+ score and secondary MF while impact of mutational status and JAK2V617Fburden have to be confirmed in larger studies. MF patients who cannot proceed to transplant likely benefit from JAK2 inhibitor prescription.
Disclosures: Milpied: Celgene: Honoraria , Research Funding . Moreau: Celgene, Janssen, Takeda, Novartis, Amgen: Membership on an entity’s Board of Directors or advisory committees .
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