Diagnosis and prognosis are supported by integrated assessment of next-generation sequencing in chronic myeloid malignancies. A real-life study.

Next-generation sequencing (NGS) is used to investigate the presence of somatic mutations. The utility of incorporating routine sequencing to guide diagnosis and therapeutic decisions remains unclear. We report the findings of an observational, multicenter study that aimed to assess the impact of somatic mutation testing by NGS in a reallife setting of chronic myeloid malignancies. A total of 177 patients were enrolled, partitioned into two overlapping groups. In group A (n=94), the indication was to search for clonal hematopoiesis, in a context of suspected myelodysplastic syndrome or myeloproliferative neoplasia. In group B (n=95), the theranostic impact of somatic mutations was studied. A panel of 34 genes was used on DNA extracted from blood or bone marrow samples. Within group A, the detection of clonal hematopoiesis supported the diagnosis of chronic myeloid malignancies for 31 patients while the absence of clonal hematopoiesis ruled out the suspected diagnosis in 47 patients. Within group B, NGS identified prognostically relevant somatic mutations in 32 patients, which had a therapeutic impact in 18 cases. By determining the presence or absence of somatic mutations, the application of NGS in daily practice was found to be useful for an integrated final diagnosis in 83% of the patients. Moreover, the search for somatic mutations had a prognostic impact that led to treatment modification in 19% of the cases. This study outlines the fact that adequate implementation of new investigations may have a significant positive medico-economic impact by enabling appropriate management of patients.

Is allogeneic stem cell transplantation for myelofibrosis still indicated at the time of molecular markers and JAK inhibitors era?

OBJECTIVE: The role of allogenic stem cell transplantation (ASCT) is still debated in myelofibrosis (MF). METHODS: A retrospective analyzed was performed to compare the outcome of 71 patients with intermediate-2 or high-risk Dynamic International Prognosis Scoring System+ (DIPSS+) primary (PMF) or secondary (SMF) myelofibrosis with an indication of ASCT as they ultimately underwent the procedure (n=34) or not (n=37). RESULTS: Five-year overall survival (OS) was not statistically different between both groups (allograft: 52% vs no allograft: 34%, P=.12). However, progression to myelodysplastic syndrome or acute myeloid leukemia at 5 years was significantly lower in transplanted patients (14% vs 50%, P=.01). In univariate analysis, 5-year OS was significantly higher for transplanted vs non-transplanted patients with unfavorable karyotype (75% vs 0%, P=.001), SMF (71% vs 20%, P=.001) or high DIPSS+ score (46% vs 15%, P=.03). There was also a trend for better 5-year OS in allografted patients with high JAK2V617F burden (>65%) (75% vs 8%, P=.07). Interestingly, the survival of patients who did not proceed to ASCT was dramatically increased by the use of ruxolitinib. CONCLUSIONS: Not all intermediate-2/high-risk DIPSS+ MF patients benefit from ASCT, especially since the introduction of JAK2 inhibitors.

Prognostic impact of immune status and hematopoietic recovery before and after fludarabine, IV busulfan, and antithymocyte globulins (FB2 regimen) reduced-intensity conditioning regimen (RIC) allogeneic stem cell transplantation (allo-SCT).

This retrospective analysis aimed to assess hematopoietic and immune recovery in a cohort of 53 patients [males: n = 33; median age: 59 yr (range: 22-70)] who received a FB2 (fludarabine 120-150 mg/m² + IV busulfan 6.4 mg/kg + antithymocyte globulin thymoglobulin 5 mg/kg) reduced-intensity conditioning (RIC) allo-stem cells transplantations (SCT). With a median follow-up of 19 months (range: 2-53), the 2-yr overall survival, disease-free survival (DFS), relapse incidence, and non-relapse mortality were 63%, 59.5%, 35%, and 6%, respectively. In univariate analysis, the factors correlated with a significantly higher 2-yr OS and DFS were a higher total circulating lymphocytes count at transplant (>730/mm(3) ; OS: 81% vs. 43%, P = 0.02; DFS: 73% vs. 45.5%, P = 0.03) and a higher recovery of leukocytes (>5300/mm(3) ) (2-yr OS: 81% vs. 44%, P = 0.007; 2-yr DFS: 72% vs. 46%, P = 0.08), neutrophils (>3200/mm(3) ) (2-yr OS: 76% vs. 50%, P = 0.03; 2-yr DFS: 67% vs. 52.0%, P = 0.1), and monocytes (>590/mm(3) ; 2-yr OS: 80% vs. 45%, P = 0.004; 2-yr DFS: 76% vs. 42%, P = 0.01) at day +30 post-transplant. In multivariate analysis, the only independent factors associated with a significantly higher OS and DFS were a better immune status at transplant (lymphocytes count >730/mm(3) ) and a higher monocytes count (>590/mm(3) ) at day +30 post-transplant. These results suggest that immune status and hematopoietic recovery before and after FB2 RIC allo-SCT can be significant predictors of outcome. This paves the way for future studies aiming to closely monitor the kinetics of immune recovery after RIC allo-SCT and to evaluate the impact of growth factors and other immunostimulatory cytokines in the setting of RIC allo-SCT.

Control of Pim2 kinase stability and expression in transformed human haematopoietic cells.

The oncogenic Pim2 kinase is overexpressed in several haematological malignancies, such as multiple myeloma and acute myeloid leukaemia (AML), and constitutes a strong therapeutic target candidate. Like other Pim kinases, Pim2 is constitutively active and is believed to be essentially regulated through its accumulation. We show that in leukaemic cells, the three Pim2 isoforms have dramatically short half-lives although the longer isoform is significantly more stable than the shorter isoforms. All isoforms present a cytoplasmic localization and their degradation was neither modified by broad-spectrum kinase or phosphatase inhibitors such as staurosporine or okadaic acid nor by specific inhibition of several intracellular signalling pathways including Erk, Akt and mTORC1. Pim2 degradation was inhibited by proteasome inhibitors but Pim2 ubiquitination was not detected even by blocking both proteasome activity and protein de-ubiquitinases (DUBs). Moreover, Pyr41, an ubiquitin-activating enzyme (E1) inhibitor, did not stabilize Pim2, strongly suggesting that Pim2 was degraded by the proteasome without ubiquitination. In agreement, we observed that purified 20S proteasome particles could degrade Pim2 molecule in vitro. Pim2 mRNA accumulation in UT7 cells was controlled by erythropoietin (Epo) through STAT5 transcription factors. In contrast, the translation of Pim2 mRNA was not regulated by mTORC1. Overall, our results suggest that Pim2 is only controlled by its mRNA accumulation level. Catalytically active Pim2 accumulated in proteasome inhibitor-treated myeloma cells. We show that Pim2 inhibitors and proteasome inhibitors, such as bortezomib, have additive effects to inhibit the growth of myeloma cells, suggesting that Pim2 could be an interesting target for the treatment of multiple myeloma.