Combination therapy with ruxolitinib plus low-dose cytarabine or mercaptopurine in patients with blast-phase myelofibrosis

Patients with myelofibrosis in blast-phase commonly have a median overall survival of only 3–6 months. Given the older median age of onset and heavy pretreatment, intensive chemotherapy often is not appropriate and has low efficacy with high toxicity. Ruxolitinib (a JAK1/2 inhibitor) has provided significant clinical benefits in patients with chronic phase myelofibrosis. We report our experience of treating blastphase myelofibrosis patients with the combination therapy of ruxolitinib plus low dose mercaptopurine or low-dose cytarabine. The cases presented here demonstrated the feasibility and tolerability of combination continuous ruxolitinib treatment with mercaptopurine or low-dose cytarabine for patients with blast-phase myelofibrosis. The efficacy of these combination regimens is encouraging

Using the Minor Variant Finder software to identify and quantify the allelic burden level of somatic mutations in oncohematologic diseases

Background. There are problems related to both quantitative assessment of an allele burden level of a mutant gene and interpretation of results in DNA samples with the burden level of the mutant allele less than 15–20 %, when using Sanger sequencing for analyzing somatic mutations. Applied Biosystems (USA) has developed new software Minor Variant Finder, which allows determining mutations with the allele burden level from 5 %.The objective: to determine the allele burden level and identification of minor variants of somatic mutations in the ASXL1, JAK2 genes and BCR-ABL oncogene using Minor Variant Finder software in patients with myeloproliferative neoplasms.Materials and methods. The level of mutant allele burden for 15 patients with myeloproliferative neoplasms was determined by the identified mutations using the Minor Variant Finder software, after analysis of point somatic mutations in the ASXL1, JAK2 genes and BCR-ABL oncogene by Sanger sequencing.Results. The allele burden level in all 5 ASXL1-positive samples and BCR-ABL-positive sample was determined as higher than 20 % using the Minor Variant Finder software. The allele burden level in 2 cases was higher than 20 % and in 7 cases lower than 20 %, when we analyzed 9 JAK2-positive samples.Conclusion. Minor Variant Finder software can be used to estimate the allele burden level and to identify minor variants of somatic mutations in the ASXL, JAK2 and BCR-ABL genes

THROMBOTIC AND BLEEDING RISK FACTORS IN ESSENTIAL THROMBOCYTHEMIA

Background. Thrombosis and hemorrhage are the main category of complications, that affects the overall survival (OS), quality of life and therapy option choice in essential thrombocythemia (ET). Molecular marker presence (JAK2V617F (JAK2+), MPL (MPL+), CALR (CALR1+-type 1, CALR2+-type 2) or its absence (triple-negative status (TN)) in ET supposed to impact on the clinical course, thrombosis rate and ET prognosis.The aim of this study was to investigate interactions between the presence of molecular marker, thrombosis/bleeding rates and the OS in ET.Methods. Outpatient’s charts of 240 ET patients, who had been diagnosed with ET at our institution according to WHO 2008 criteria. The following data were assessed: complete blood count, bone marrow biopsy results, bone marrow cytogenetic, the restriction fragment length polymorphism (RFLP) results used for JAK2V617F detection, in case of JAK2V617F-negative status the PCR-RFLP results (MPL detection) and the direct sequencing results (CALR detection). Different thrombotic/bleeding complications rates were analyzed. The OS in ET patients was compared according to complications and IPSET-thrombosis groups. Results. Among 240 pts 183 (76.3 %) hadn’t any thrombotic complication or bleeding event (no complications/NC), 57/240 (23.7 %) had complications: 49/57 (85.9 %) reported arterial or/and venous thrombosis, stroke or heart failure (thrombosis+) and 11/57 (19.3 %) had bleeding events (hemorrhage+). Thrombotic complications in JAK2+ had 27.4 % (50/182) pts, in TN – 30.7 % (8/26) pts, in CALR1+ – 18.2 % (2/11) pts and no cases of thrombosis were detected in CALR2+ and MPL+ subgroups (p < 0,001). There were significant statistical differences in median platelet count as follows: 742 . 10 9/L (thrombosis+) and 937 . 10 9/L (hemorrhage+) (p = 0.003). No significant statistical differences in median hemoglobin and leukocyte count (р = 0.75 and р = 0.47) were detected. There were more than a half pts older than 60 years in groups NC (51 %) and thrombosis+ (59 %) and in group hemorrhage+ only 36 % (p < 0,001). Cardiovascular risk factors were reported in 24 % pts (NC), 69 % pts (thrombosis+) and 36 % pts (hemorrhage+) (p < 0,001). There were no significant statistical differences in follows risk factors as platelets count > 1000 . 10 9/L and leukocytosis > 11 . 10 9/L (р = 0.85 and р = 0.72). No significant differences in OS among groups NC, thrombosis+ and hemorrhage+ (р = 0.21) and IPSET-thrombosis groups (р = 0,068) were found. Conclusion. Along with common thrombotic risk factors (age > 60 and cardiovascular risk factors) mutational status may help to identify ET course. Leukocytosis > 10 . 10 9/L and thrombocytosis > 1000 . 10 9/L cannot be assessed as independent thrombosis risk factors in ET. The JAK2V617F mutation was associated with increased risk of thrombotic complications in ET. CALR mutations were associated with lower thrombosis risk, comparing to JAK2+ status despite the fact of CALR+ patients had higher platelets level