High mutation burden in the checkpoint and micro-RNA processing genes in myelodysplastic syndrome.

A number of sequencing studies identified the prognostic impact of somatic mutations in myelodysplastic syndrome (MDS). However the majority of them focused on methylation regulation, apoptosis and proliferation genes. Despite the number of experimental studies published on the role of micro-RNA processing and checkpoint genes in the development of MDS, the clinical data about mutational landscape in these genes is limited. We performed a pilot study which evaluated mutational burden in these genes and their association with common MDS mutations. High prevalence of mutations was observed in the genes studied: 54% had mutations in DICER1, 46% had mutations in LAG3, 20% in CTLA4, 23% in B7-H3, 17% in DROSHA, 14% in PD-1 and 3% in PD-1L. Cluster analysis that included these mutations along with mutations in ASXL1, DNMT3A, EZH2, IDH1, RUNX1, SF3B1, SRSF2, TET2 and TP53 effectively predicted overall survival in the study group (HR 4.2, 95%CI 1.3-13.6, p = 0.016). The study results create the rational for incorporating micro-RNA processing and checkpoint genes in the sequencing panels for MDS and evaluate their role in the multicenter studies.

A Prospective Pilot Study of Graft-versus-Host Disease Prophylaxis with Post-Transplantation Cyclophosphamide and Ruxolitinib in Patients with Myelofibrosis.

INTRODUCTION: This prospective study evaluated a calcineurin inhibitor-free graft-versus-host disease (GVHD) prophylaxis regimen of ruxolitinib in combination with post-transplant cyclophosphamide (PTCy). Patents and Methods: Twenty patients with primary or secondary myelofibrosis were prospectively enrolled. Reduced intensity conditioning was performed, followed by allogeneic stem cell transplantation from related (n = 7) or unrelated (n = 13) donors. GVHD prophylaxis included only PTCy and ruxolitinib (45 mg) from day-7 to day-2, and 15 mg from day+5 to day+100. This trial was registered at www.clinicaltrials.gov as #NCT02806375. RESULTS: Primary engraftment was documented in 17 patients. One patient experienced primary graft failure and 2 died before engraftment. Eleven patients demonstrated severe poor graft function (SPGF), which required ruxolitinib dose reduction. The regimen was well tolerated, with grade 3-4 non-haematological toxicity in 30%, viral reactivation in 45%, and severe sepsis in 15% of patients. The incidence of acute GVHD grade II-IV was 25%, grade III-IV GVHD was 15%, and moderate chronic GVHD was 20%, with no severe cases. Only 2 patients required systemic steroids. Haematological relapse was documented in 1 patient. Two-year non-relapse mortality was 15%, 2-year overall survival was 85%, and 2-year event-free survival was 72%. CONCLUSION: GVHD prophylaxis with PTCy and ruxolitinib is associated with low toxicity, good acute and chronic GVHD control, and low relapse incidence. However, the relatively high rate of SPGF should be taken into account. SPGF could possibly be mitigated by ruxolitinib dose reduction.

Splenectomy following JAK1/JAK2 inhibitor therapy in patients with myelofibrosis undergoing allogeneic stem cell transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is the only treatment option with curative potential in patients with myelofibrosis (MF). The aim of our study was to evaluate the safety of splenectomy before alloHSCT in MF patients who failed to achieve significant spleen response after ruxolitinib therapy. METHODS: Splenectomy was performed in 12 patients for alloHSCT with myelofibrosis-primary (6 patients), post-polycythemia vera (3 patients). or postessential thrombocythemia (3 patients) between 2016 and 2018. The patients were prospectively included in the study if persistence of splenomegaly ≥ 25 cm was documented after at least 3 months of ruxolitinib therapy. In eight patients subsequent alloHSCT was performed. RESULTS: Median length of hospital stay was 11 (8-30) days, median follow-up after splenectomy was 20.0 (0.6-31.1) months. No deaths were documented, perioperative morbidity was 50%. Three patients experienced portal vein thrombosis and one experienced splenic vein thrombosis. One patient developed pancreonecrosis and subdiaphragmatic abscess. Mean leukocyte count was significantly higher 1 month after splenectomy than before, 10.7 ±â€¯1.7 versus 6.9 ±â€¯2.3 × 109/L (p = 0.03). Platelets rate significantly elevated starting Day + 7 after splenectomy (p = 0.01). Median time between splenectomy and alloHSCT was 2.6 (0.17-4.5) months. All patients achieved engraftment. In early posttransplant period no cases of severe sepsis, intraabdominal infections were documented. One patient died after alloHSCT due to thrombotic microangiopathy. Seven patients are alive in disease complete remission. No relapses after alloHSCT were observed. Two-year overall survival in the whole group is 90% (95%CI 98-43%). CONCLUSION: Splenectomy before alloHSCT might be a promising option in patients who failed to achieve significant spleen response after ruxolitinib therapy.