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The development of National clinical guidelines on diagnosis and treatment of Ph-negative myeloproliferative neoplasms comes in response to the need to standardize the approach to diagnosis and treatment. The availability of clinical guidelines can facilitate the choice of adequate treatment strategy, provides practicing physicians with exhaustive and up-to-date information on advantages and shortcomings of different treatment methods as well as lets health professionals better assess expected extents of treatment required by patients. In 2013 a working group was formed to develop and formulate clinical guidelines on the treatment of myeloproliferative neoplasms. These guidelines were first published in 2014, afterwards they were revised and republished. The dynamic development of current hematology presupposes constant updating of knowledge and implementation of new diagnosis and treatment methods in clinical practice. In this context clinical guidelines present a dynamic document to be continuously amended, expanded, and updated in accordance with scientific findings and new requirements of specialists who deal directly with this category of patients. The present edition is an upgraded version of clinical guidelines with updated information on the unification of constitutional symptoms assessment using MPN-SAF TSS questionnaire (MPN10), on applying prognostic scales in primary myelofibrosis, assessing therapy efficacy in myeloproliferative neoplasms, revising indications for prescription, on dose correction, and discontinuation of targeted drugs (ruxolitinib). The guidelines are intended for oncologists, hematologists, healthcare executives, and medical students.

Aim. To study the relationship of karyotype, JAK2, CALR, and MPL driver mutations and ASXL1 mutation status with the progression and prediction of primary myelofibrosis (PMF). Materials & Methods. The trial included 110 PMF patients (38 men and 72 women), median age was 59 years (range 18-82) with median follow-up after diagnosis of 2.6 years (range 0.1-23). The patients were examined for JAK2, CALR, MPL, and ASXL1 mutations. Restriction fragment length polymorphism technique was used for the analysis of V617F substitution in JAK2 and 515 codon mutation in MPL. CALR (exon 9) and ASXL1 (exon 12) mutation tests were performed using Sanger direct sequencing. In 48 (44 %) out of 110 patients bone marrow cell karyotype was determined. Clinical and hematological parameters and median overall survival (OS) of patients were analyzed with regard to detected genetic aberrations and combinations of them. Results. JAK2, CALR, MPL mutations were detected in 55 (50 %), 28 (25.5 %), and 7 (6.4 %) out of 110 patients, respectively. Triple negative (TN) status was identified in 20 (18.2 %) out of 110 examined patients. ASXL1 mutations were detected in 22 (20 %) out of 110 patients. Out of 48 patients in 32 (66.7 %) normal karyotype, in 3 (6.3 %) favorable karyotype, in 4 (8.3 %) intermediate-prognosis karyotype, and in 9 (18.7 %) unfavorable karyotype were detected. The comparison of clinical and hematological parameters showed a number of significant differences. JAK2-positive patients had a higher hemoglobin level (median 129 g/L; p = 0.021). TN was associated with a high IPSS risk (p = 0.011), low hemoglobin level (median 101 g/L; p = 0.006), drop in platelet count (median 266 x 109/L; p = 0.041), increased lymphocyte count (median 26.9 х 109/L; р = 0.001). The detection of terminating mutations in ASXL1 correlated with palpable enlarged spleen (р = 0.050), reduced platelet count (median 184 х 109/L; р = 0.016), leukocyte count > 25 х 109/L (р = 0.046), and blast count > 1 % (р < 0.001). Univariate regression analysis showed that terminating mutations in ASXL1 (hazard ratio [HR] 2.9; р = 0.018), unfavorable karyotype (HR 8.2; р < 0.001), and TN (ОР 8.1; р < 0.001) had prognostic value for OS. ASXL1 mutation was associated with significantly worse OS in TN patients. Median OS of ASXL1-negative patients without high-risk chromosomal aberrations was significantly longer than in patients with high-risk karyotype and/ or ASXL1 mutation. Conclusion. Several genetic defects in tumor cells are associated with phenotypic manifestations of PMF. Based on the results of cytogenetic analysis and mutation determination of JAK2, CALR, MPL, and ASXL1, patients can be classified in different “genetic” risk groups when PMF is diagnosed.

Background. In multiple myeloma (MM) treatment a single autologous hematopoietic stem cell transplantation (auto-HSCT) is preceded by conditioning regimens aimed at intensifying cytoreductive effect. In the course of ongoing search for combined conditioning regimens an attractive option proved to be thiotepa/melphalan combination. Aim. Data analysis of a pilot study of the efficacy of conditioning regimens including administration of two alkylating agents (thiotepa and melphalan) with subsequent auto-HSCT. Materials & Methods. 9 patients received 10 auto-HSCTs with conditioning regimen including administration of 250 mg/m2 of thiotepa on Day -5 and 140 mg/m2 of melphalan on Day -2. After auto-HSCT pegylated filgrastim was administered in 8 patients. Engraftment period was calculated on the basis of absolute neutrophil count ≥ 0,5 x 109/L and thrombocyte level ≥ 20 x 109/L. Regimen toxicity was assessed according to CTCAE v5.0. Survival rates were estimated by Kaplan-Meier curves. Results. The use of thiotepa did not require administration of any additional drugs. The incidence of mucositis and enteropathy of grade 1-2 was 100 % and 70 %, respectively. Pyrexia was reported in 7 auto-HSCTs. Pneumonia occurred in 1 patient. The infusion of 1-3 doses of platelet concentrate (median of 2 doses) was required in all patients except for one. Donor erythrocytes were transfused to 3 patients. Engraftment was reported in all patients within the period of 10-14 days. Median hospitalization duration from Day 0 to hospital discharge was 16 patient-days. After auto-HSCT the quality of response improved in 6 out of 9 patients. MM progression was reported in one patient with complex karyotype. Further follow-up showed progression in 2 patients. By December 2018 median follow-up of 9 patients from the date of auto-HSCT was 9 months (range 3-20 months), me dian progression-free survival was 17 months, median overall survival was not reached. Conclusion. Acceptable toxicity, improvement of response quality, and maintenance of it for up to 20 months allow to consider combined conditioning regimen Thio/Mel to be a possible alternative to the standard Mel200 regimen.

Aim. To analyze the effect on prognosis of mutations that are typical of acute myeloid leukemia (AML) patients. Materials & Methods. The study included 620 AML patients surveyed at Hematology Clinics of Saint Petersburg (Russia) and Charite Clinic (Berlin, Germany). G-banding of chromosomes was employed for cytogenetic testing. Aberration screening in DNMT3A, IDH1/2 genes was based on real-time polymerase chain reaction (PCR) with subsequent analysis of melting and sequencing profiles. Mutations in FLT3, NPM1 genes were revealed by PCR. Results. Mutations were identified in 343 (55.3 %) out of 620 patients. Significantly more often mutations were discovered in patients with normal karyotype (NK) (p = 0.001). FLT3-ITD mutation was associated with reduced medians of overall survival (OS) and disease-free (DFS) survival: 11.3 vs. 15.8 months with FLT3-ITD- (p = 0.005) and 10.0 vs. 13.3 months with FLT3-ITD+ (p = 0.009), respectively. The relation of FLT3-ITD allele burden to OS duration was also assessed. In the ITDlow/ITD- group the OS median was considerably longer than in the ITDhigh group (p = 0.028). In the group of patients with 1 mutation in NPM1 gene OS and DFS were much better in comparison with other patients (medians of 27.4 and 13.9 months, respectively, p = 0.040; 19.3 and 12.0 months, p = 0.049). Negative impact of mutations in DNM-T3A gene was noticed while assessing OS median: 12 (DN-MT3A+) and 15 months (DNMT3A-), respectively (p = 0.112). Mutations in IDH1 gene correlated with a better OS than in the group without mutations (p = 0.092). The rs11554137 polymorphism in IDH1 gene was associated with worse OS in the group of patients with NK (p = 0.186). In 144 patients various mutation combinations (from 2 to 5) were identified. It was demonstrated that mutations in FLT3 (FLT3-ITD), NPM1, DNMT3A, and IDH2 were identified significantly more often in combinations with other mutations (p = 0.001): NPM1+/ FLT3-ITD+ (20.8 %), NPM1+/FLT3-ITD+/DNMT3A+ (8.3 %), and FLT3-ITD+/DNMT3A+ (8.3 %). Patients with 1 mutation had a noticeably longer OS median compared with patients with 2 mutations (18.1 and 12.2 months; p = 0.003). In patients with NPM1+ according to their OS the most unfavorable additional mutation was FLT3-ITD (median 27.4 vs. 9.2 months; p = 0.019) and the combination of NPM1+/FLT3-ITD+/DNM-T3A+ (median 27.4 vs. 14.6 months; p = 0.141). OS of patients with DNMT3A+ showed a downward trend if FLT3-ITD additional mutation was identified (17.3 vs. 7.1 months; p = 0.074). Conclusion. Mutations in FLT3, DNMT3A, IDH1/2, NPM1 genes frequently occur in AML intermediate-risk patients, i.e. they determine the intermediate prognosis group in AML. The studied mutations considerably impact prognosis. It is important to take into consideration mutation type, its allele burden, and the presence of additional mutations. A patient with 2 mutations has a considerably worse OS compared with a patient with 1 mutation. The studied group of patients with the combination of NPM1+/FLT3-ITD+, NPM1+/ FLT3-ITD+/DNMT3A+, DNMT3A+/FLT3-ITD+ mutations has the poorest prognosis. Comprehensive analysis of genetic damages in AML patients allows to most accurately predict the course and prognosis of the disease and to plan targeted therapy.

Aim. To evaluate the clinical experience of bosutinib use for treatment of chronic myeloid leukemia (CML) patients with intolerance and resistance to other tyrosine kinase inhibitors (TKI), as well as to compare the obtained results with the data of clinical trials. Materials & Methods. The analysis was conducted on case history records of 51 CML patients (25 men and 26 women; median age was 56 years, range 28-86). By the beginning of bosutinib therapy 37 chronic phase, 8 acceleration phase, and 6 blast crisis patients were included in the study. Bosutinib was administered as second-line TKI treatment in 10 patients, as third-line treatment in 18 patients, and as fourth-line treatment in 23 patients. The causes for switching to bosutinib were poor tolerance of previous TKI therapy in 21 patients and resistance to previous TKI therapy in 30 patients. Results. The median duration of bosutinib treatment was 6 months (range 1-50). Bosutinib toxicity profile and its tolerance in common clinical practice corresponded to the data of clinical trials. Because of adverse events the therapy was discontinued only in 5 (10 %) patients. Complete hematological response was 88 % (persistent response was maintained in 76 % of patients); complete cytogenetic response (CCyR) was 39 %, (persistent response in 37 % of cases); major mo- lecular response (MMR) was 31 % (it was confirmed in 25 % of patients during the last follow-up visit). The efficacy of bosutinib in the real clinical setting was slightly higher compared to the results of clinical trials. This difference was associated with a disease phase, a reason for withdrawal of the previous TKI, line of treatment, BCR-ABL mutations, and the form of them. The therapy was continued in 22 (43 %) patients, most of them reached stable optimal response, both CCyR and MMR. Conclusion. Bosutinib appears to be an acceptable alternative to other TKIs having its specific mechanisms of action and adverse events. The efficacy and safety of bosutinib proved in routine clinical practice are sufficient to recommend it for use in national hematology.

To assess the results of following up patients with chronic myeloid leukemia (CML) and a deep molecular response (MR) without tyrosine kinase inhibitor (TKI) therapy.The reasons for TKI discontinuation in 70 patients with CML and a deep MR of more than 1 year's duration were adverse events, pregnancy, and patients' decision. Information was collected retrospectively and prospectively in 2008-2016.The median follow-up after TKI therapy discontinuation was 23 months (2 to 100 months). At 6, 12 and 24 months after TKI therapy discontinuation, the cumulative incidence of major MR (MMR) loss was 28, 41 and 48%, respectively; the survival rates without TKI therapy were 69, 50, and 39%, respectively. MMR loss was noted in 28 (88%) patients at 12 months; it was not seen without TKI therapy at 2-year follow-up. Deaths due to CML progression were absent. The Sokal risk group was a reliable factor influencing MMR loss (p ≤ 0.05). The cumulative recovery rate for deep MR after resumption of TKI use was 73 and 100% at 12 and 24 months, respectively, with a median follow-up of 24 months (1 to 116 months). Deep MR recovered at a later time when the therapy was resumed more than 30 days after MMR loss.Safe follow-up is possible in about 50% of the patients with CML and stable deep MRs without TKI therapy. The introduction of this approach into clinical practice requires regular molecular genetic monitoring and organizational activities. Biological factors in maintaining remission after TKI discontinuation need to be separately studied.Цель исследования. Оценка результатов наблюдения больных хроническим миелолейкозом (ХМЛ) с глубоким молекулярным ответом (МО) без терапии ингибиторами тирозинкиназ (ИТК). Материалы и методы. Причинами отмены ИТК у 70 больных ХМЛ с длительностью глубокого МО более 1 года служили нежелательные явления, беременность, собственное решение больных. Сбор информации осуществлялся ретроспективно и проспективно в 2008-2016 гг. Результаты. Медиана времени наблюдения после отмены терапии ИТК составила 23 мес (от 2 до 100 мес). Кумулятивная частота потери большого молекулярного ответа (БМО) после прекращения терапии ИТК через 6, 12 и 24 мес составила 28, 41 и 48% соответственно, выживаемость без терапии ИТК - 69, 50 и 39% соответственно. У 28 (88%) пациентов потеря БМО отмечена в течение 12 мес; после 2 лет наблюдения без терапии ИТК потери БМО не отмечалось. Летальные исходы от прогрессии ХМЛ отсутствовали. Группа риска по Sokal являлась достоверным фактором, влияющим на потерю БМО (p≤0,05). Кумулятивная частота восстановления глубокого МО после возобновления приема ИТК составляла 73 и 100% через 12 и 24 мес соответственно при медиане наблюдения 24 мес (от 1 до 116 мес). Восстановление глубокого МО наблюдалось позднее при возобновлении терапии более, чем через 30 дней после потери БМО. Заключение. Примерно у 50% больных ХМЛ со стабильным глубоким МО возможно безопасное наблюдение без терапии ИТК. Для внедрения этого подхода в клиническую практику необходимы обеспечение регулярного молекулярно-генетического контроля и организационные меры. Биологические факторы сохранения ремиссии после отмены ИТК нуждаются в отдельном изучении.

Background. Myelofibrosis (primary myelofibrosis, postessential trombocythemia myelofibrosis, post-polycythemia myelofibrosis) is the most complex and pressing problem among all Ph-negative myeloproliferative diseases. The present article summarizes the author's experience of using new Janus kinase inhibitors in routine clinical practice, and compares the data with the results of other clinical research. Aim. To evaluate the use of ruxolitinib in patients with myelofibrosis. Materials & Methods. Our analysis includes 48 patients (21 men and 27 women) with histologically verified myelofibrosis (primary myelofibrosis in 36 cases, post-essential trombocythemia myelofibrosis in 10 cases, and post-polycythemia myelofibrosis in 2 cases) in a chronic stage. All patients received ruxolitinib. Median age at the start of therapy was 60 years (range from 35 to 79). Massive splenomegaly (> 10 cm below the costal margin) was found in 34 (71 %) of 48 patients. The initial dose of ruxolitinib was determined by the platelet level. The efficacy of the therapy was evaluated in accordance with ELN 2013 criteria. Results. Median duration of treatment was 18 months (range from 1 to 50 months). Symptoms of intoxication were relieved in 33 of 37 patients (89 %). The spleen size decreased in 64 % of patients. In 33 % of cases spleen size did not change, whereas an increase was observed in 3 % of patients. In the majority of patients hemoglobin level remained stable through the course of treatment. Three of 14 transfusion dependent patients did not require blood transfusions after 3 months of therapy. In patients with high thrombocyte levels prior to ruxolitinib therapy the mean level was approaching normal by the end of the 1st month of treatment. The median JAK2V617F mutant allele burden at the beginning treatment was 56.5 % (n = 20; 22.5-126.1 %). After 6 moths of treatment it accounted for 62.3 % (n = 11; 25.4-79.7 %) and in 12 months accounted for 47.4 % (n = 12; 14.2-102.2 %). By the time of the analysis 42 of 48 patients continued the ruxolitinib treatment (88 %). Death occurred in 4 patients. Overall 1-year (92 %) and 2-year (87 %) survival corresponds to the data of COMFORT-I, COMFORT-II and JUMP clinical trials. Conclusion. Ruxolitinib showed to be an effective treatment for myelofibrosis. The most pronounced and rapid effect ruxolitinib had on the spleen size and the symptoms of intoxication. The tolerability of ruxolitinib was satisfactory in the majority of patients. According to the author's data, ruxolitinib had a small impact on the JAK2V617F mutant allele burden. The overall survival rate in patients with myelofibrosis, receiving ruxolitinib in the clinical setting was similar to that of in the clinical trials.

Background & Aims. The presence of different molecular genetic markers of clonality (mutations in JAK2, MPL, CALR) or their absence (triple negative status, TN) in essential thrombocythemia (ET) indicates a biological heterogeneity of the disease and can determine its clinical forms. The aim was to evaluate the association of molecular genetic markers with the clinical form and the prognosis of ET. Materials & Methods. We analyzed the data of 240 patients with ET at the age of 20-91 years (median age 58.7 years), who were observed in the Russian Research Institute of Hematology and Transfusiology from 1999 to 2016 (median observation period 37.2 months). Results. The JAK2V617F (JAK2+) mutation was found in 182 (75.9 %) of 240 patients. CALR (CALR+) mutations were found in 30 (12.5 %): type 1 (CALP7+) mutations in 13/30 (43.3 %) and type 2 (CALR2+) in 17/30 (56.7 %). MPL (MPL+) mutations were found in only 2 (0.8 %) of 240 patients. None of the mutations were detected in 26 (10.8 %) of 240 patients (TN status). Significantly higher platelet counts were observed in CALP7+ and CALR2+ subgroups during the primary diagnosis of ET compared with JAK2+ and TN groups. The mean platelet counts were 1252 * 109/L for CALR2+ and 1079 * 109/L for CALP7+ vs 841 * 109/L (p < 0.001; p = 0.06) and 775 * 109/L (p < 0.001; p = 0.04) for JAK2+ and TN, respectively. Thrombosis was diagnosed in 50 (27.4 %) of 182 patients of the JAK2+ subgroup, in 8 (30.7 %) of the 26 patients of the TN subgroup, and in 2 (18.2 %) of 11 patients of the CALP7+ subgroup. No thrombosis was found in the CALR2+ and MPL+ subgroups (p < 0.001). In general, the CALP7+ status was characterized as the most favorable in terms of prognosis (5-year overall survival rate of 100 %), compared to the least favorable TN status (5-year overall survival rate of 85 %). Conclusion. Mutations in the CALR gene were characterized by a more favorable prognosis in comparison with JAK2+and TN, as well as a decrease in the risk and frequency of thrombosis, despite higher platelet counts. TN-status of ET was associated with unfavorable prognosis.

Background. Thrombotic complications are one of the main problems of polycythemia vera (PV) treatment. They significantly impair the quality of life of these patients and may lead to the lethal outcome. A thrombotic event often precedes the diagnosis of this hematological disease. The pathogenesis of thrombosis in myeloproliferative neoplasms, PV, in particular, is a complex one. Prescription of antiaggregants in the absence of thrombosis and anticoagulants after a thrombotic event requires special attention and development of corresponding recommendations. The prescription of anticoagulants is impossible without taking into account the risks of hemorrhagic complications, which are also typical for myeloproliferative neoplasms. Aim. Assessment of the impact of hereditary thrombophilia genetic markers on the risk of thrombotic complications in patients with PV. Methods. The study examined 116 patients with PV, who were screened for markers of hereditary thrombophilia: factor V (G1691A, FV Leiden), prothrombin, methylene-tetrahydrofolate reductase (MTHFR), fibrinogen (F/), plasminogen activator inhibitor (PA/-1), and platelet fibrinogen receptor type ///A (GP///A). The incidence of these markers and their role in thrombosis in such patients was investigated. Results. The study provided data on the incidence of hereditary thrombophilia markers in patients with PV. Statistically significant differences in the incidence of these markers and homocysteine level were found between patients with thrombosis and without them. Conclusion. The information about the hereditary thrombophilia markers presence may be useful for the prescription of adequate antiaggregant and anticoagulant therapy for PV patients. Further research in this field is justified and it will probably demonstrate the relevance of hereditary thrombophilia markers as prognostic factors for thrombotic complications risk assessment.

Introduction.In recent times, more and more data are available on the mechanisms of development of primary and secondary resistance to therapy with tyrosine kinase inhibitors (TKIs) in patients with CML. The use of next-generation sequencing (NGS) allows detecting mutations in theBCR-ABLkinase domain (KD) in some patients with resistance to TKI therapy. However, the reasons for resistance in patients without mutations in theBCR-ABLKD are still unclear. Aim.To determineBCR-ABL-independent molecular genetic markers of resistance to TKI therapy in patients with CML using NGS. Materials and methods.We examined blood samples from 15 patients with resistant CP CML (8 men and 7 women) aged 32 to 59 years (Me = 44 years). Resistance to TKI therapy was determined according to the ELN 2013 criteria. In this group: 2 patients received therapy with 2 TKIs, 8 patients with 3 TKIs, 3 patients - 4 TKIs, and 2 patients received 5 TKIs (Me = 3 TKIs). Cytogenetic test revealed trisomy 8 in 3 patients. One patient was diagnosed with the T315I mutation at once. The patients underwent NGS examination of the myeloid panel, which included 55 genes, with an average reading depth of 1000x using a MiSeq device (Illumina). The 2% threshold of variant allele frequency (VAF) was used. The clinical significance of mutations was evaluated using the COSMIC, ClinVar and OMIM databases. Results.By NGS we identified genetic aberrations in all patients: an average of 5 mutations (from 1 to 10 in one patient). A total of 77 mutations with unclear clinical significance were identified: 54 of them were missense mutations, 22 were synonymous mutations, and 1 frameshift mutation. The most common abnormalities were found in theNF1(10),TET2(8),ATRX(7), andSTAG2(6) genes. In 2 patients, the simultaneous presence of mutations in theATRXandNF1genes was found, they had a primary-resistant course of the disease, MMR was not achieved even on the 3rd and 4th lines of targeted therapy. Three patients were found to have simultaneous mutations in theNF1andSTAG2genes, including two patients who also had a primary-resistant course of the disease, and one of them showed resistance to all 5 TKIs. In 2 patients with the simultaneous presence of mutations in theATRXandTET2genes, resistance to 2 TKIs was registered; CCyR without MMR was achieved only with ponatinib. In 3 patients with singleSTAG2mutations, MMR was achieved on the third line of TKI. One patient with 3 mutations inTET2also achieved MMR only on the third line TKI. Mutations inTET2are more common in Ph-negative MPNs. In our study, mutations were most often detected in theNF1,ATRXandSTAG2genes. Although mutations in theNF1andATRXgenes have been described previously, they were found in responding patients with CP CML (Kim et. al. Blood 2017). In our study, mutations in these genes were found in therapy-resistant patients with an unfavorable course of the disease. TheNF1gene encodes a GTPase activating protein (GAP), which is involved in inhibiting the RAS/MAPK signal transduction pathway and is a tumor suppressor. Mutations in this gene are often associated with the development of CMML and JMML, resistance to therapy and decreased overall survival. TheATRXgene encodes a protein involved in chromatin remodeling, regulation of transcription, replication, and maintenance of telomere structure. TheSTAG2gene encodes a protein that is part of the cohesin complex. Possibly, abnormalities in these genes may belong to a clone of leukemic stem cells (Vetrie et. al. Nature 2020), cause their resistance to TKI,BCR-ABL-independent proliferative potential and their genetic instability. In addition, some of these mutations, possibly, are preleukemic - they could precede the emergence of the Ph-clone in such patients by the mechanism of clonal hematopoiesis of indeterminate potential and may cause an unfavorable prognosis. This allowed us to suggest the prognostic and therapeutic value of mutations in theNF1,ATRXandSTAG2genes in CP CML patients with resistance to TKI therapy. Conclusion.The obtained results of a pilot study of NGS use for predictingBCR-ABL-independent resistance to TKI therapy in patients with CML can serve as a basis for further research aimed at developing prognostic models and choosing a treatment method for resistance to targeted therapy. Disclosures Voloshin: Novartis:Honoraria, Speakers Bureau.Fominykh:Novartis:Honoraria, Speakers Bureau;Pfizer:Honoraria, Speakers Bureau;BMS:Honoraria, Speakers Bureau.Shuvaev:Novartis:Honoraria, Speakers Bureau;BMS:Honoraria, Speakers Bureau;Pfizer:Honoraria, Speakers Bureau.Martynkevich:Pfizer:Honoraria, Speakers Bureau;BMS:Honoraria, Speakers Bureau;Novartis:Honoraria, Speakers Bureau.

We aimed to characterize withdrawal syndrome (WS) and evaluate factors associated with its development in the prospective clinical study RU-SKI in patients with chronic myeloid leukemia with deep molecular response who discontinued tyrosine kinase inhibitor (TKI) therapy. In total, 98 adult patients with chronic myeloid leukemia chronic phase, TKI therapy ≥ 3 years, and deep molecular response (BCR-ABL ≤ 0.01%) ≥ 2 years were enrolled and observed without treatment. WS was defined as newly observed or worsening musculoskeletal pain after TKI cessation. WS symptoms were found in 41 (42%) of 98 patients with a median time of observation of 25 months (range, 12-42 months). WS grades 1 to 2 and grade 3 were observed in 39 (95%) and in 2 (5%) patients, respectively. The median duration of WS was 5 months (range, 1-25 months). WS was resolved in 37 (90%) patients. Anti-inflammatory therapy was used in 21 (51%) patients. Older age (P = .039) and longer TKI therapy (P = .001) were associated with WS. The 2-month landmark analysis found no association of WS development and the rate of molecular relapses. In total, 42% of the patients experienced WS after TKI therapy discontinuation in the RU-SKI study. Physicians should be warned about the possibility of WS development, and patients of older age and with longer TKI treatment need special attention.

Background & Aims. Interpretation of key aspects of pathogenesis of chronic myeloid leukemia (CML) and development and introduction of target therapy have changed the prognosis of this once fatal disease dramatically. Results of numerous clinical trials demonstrated substantial superiority of tyrosine kinase inhibitors over previous therapy techniques. At the same time, clinical trials had limitations in patient enrollment, as well as treatment conditions and duration. The analysis of our clinical experience in CML target therapy (over the period from 2003 till 2015) is an important argument for introduction of novel drugs into routine clinical practice. The aim of the study is to analyze our own experience in CML target therapy and to compare our results with clinical trials data. Methods. Outpatient’s cards and case histories of CML patients treated in the Russian Scientific Research Institute of Hematology and Transfusiology over last 12 years were analyzed in this work. Published results of multi-center clinical trials evaluating the use of tyrosine kinase inhibitors in CML were used for a comparative analysis. The primary morbidity rate and the prevalence of CML, results of first and subsequent treatment lines were studied with assessment of survival rates, adverse events, and the nature of the response (hematologic, cytogenetic and molecular). Results. The experience in treatment of 208 CML patients was analyzed. The use of imatinib led to clinical and hematological remission (complete hematologic response) was achieved in 95 % of patients. The frequency of complete cytogenetic responses (CCyR) was 69 %, and that of major molecular responses (MMR) was 58 %. The overall 5-year survival (OS) was 86.4 %, the 10-years OS was 67.5 %. The use of nilotinib during the second line permitted to achieve CCyR in 61 % of patients, and the MMR in 55 % of cases. The two-year OS was 96 % and the 5-year OS was 68 %. CCyR and MMR were achieved in 50 % patients treated with dasatinib during the second line. As for the third line, CCyR was achieved in 50 % of patients and MMR in 25 %. In case of previous imatinib and nilotinib resistance, CCyR was observed only in 36 % of patients and MMR in 18 % of cases. During second-line dasatinib treatment, the 2-year OS was 85 %, and the 5-year OS was 51 %; as for the third line, the results were 75 % and 50 %, respectively. The range and rates of adverse events of the therapy, in general, corresponded to results of clinical trials. Conclusion. The use of tyrosine kinase inhibitors in treatment of CML permits to prolong patient’s life span and quality of life significantly. The use of nilotinib and dazatinib (in case of nilotinib intolerance and/or resistance) could be effective in most patients.

Background: Rapid progress in next-generation sequencing (NGS) technologies make it possible to spell out the mutational status, the genetic and epigenetic variability of chronic lymphocytic leukemia (CLL). The identification of driver mutations allows us to expand understanding of the pathogenesis of CLL, to identify prognostic groups and to select potential targets for therapy, contributing to the development and implementation of new targeted drugs and its combinations. Nevertheless, the course of CLL does not always correspond to the existing prognostic risk groups, assessed by "standard" cytogenetic and molecular genetic methods. The NGS technology admits establishing markers of an unfavorable course of the disease. Aim: To assess the mutational status of patients (pts) with CLL using the developed Lymphoid Targeted NGS Panel and to study the possible correlation of the mutational status with the clinical characteristics of the disease. Method: In this prospective study were included 24 pts with CLL: treatment-naïve (n=8) and relapsed/refractory (n=16). The diagnosis of CLL was established according to iwCLL criteria (iwCLL, Hallek et al., 2018) and show only typical immunophenotype. The pts were divided into three prognostic groups according to cytogenetic assay: favorable (n=14), neutral (n=2), and unfavorable (n=8). Although, 20/24 pts were divided into two prognostic groups taking into account the data on the mutational status of the immunoglobulin heavy-chain variable (IGHV) region: favorable (n=8) and unfavorable (n=12). Four patients have no available data on IGHV mutational status. All patients had indications for starting treatment: FCR (n=7), RB (n=6), ibrutinib (n=3), venetoclax (n=1), acalabrutinib (n=5), combination of venetoclax and acalabrutinib (n=2). DNA samples were extracted from peripheral B-cell lymphocytes via the standard phenol-chloroform method. Average reading depth of 1000x is produced on a MiSeq platform (Illumina, USA). The 2% threshold of allele frequency (VAF) was used. The clinical significance of mutations was established using the following databases: COSMIC, ClinVar, gnomAD with application in silico analysis (Cscape, Cancer Genome Interpreter, SNPs&Go). The Lymphoid Panel includes 117 genes, part of which is involved in the main 8 cellular signaling pathways underlying the pathogenesis of CLL. We have completed a pilot NGS study using the developed Lymphoid Targeted Gene Panel on DNA samples of six treatment-naïve pts. Results: Genetic aberrations were identified in all DNA samples using NGS. Somatic mutations were detected in 82.9% of cases, in an amount from 15 to 37. In four pts (4/6) with an unfavorable prognosis (cytogenetics and unmutated IGHV), known pathogenic variants of mutations were identified: JAK3 V722L, NOTCH1 P2514fs*4, IDH2 T352P, TP53 Lys120Glu, BRAF D594G. The existing approach to the interpretation of the results does not allow making an unambiguous conclusion about the clinical significance of variants in the IDH2 and JAK3 genes, despite the known pathogenic effect of the variants. The detected variant of the mutation (Lys120Glu) in the TP53 gene is often associated with the presence of a 17p13 deletion, which was confirmed by the FISH assay and correlated with the unfavorable clinical course of the disease in patient CLL-024. Twenty-two mutations were identified, the pathogenicity of which has not yet been determined, in the amount of 2 to 5 (median=3.5) mutations per patient. It should be noted that two patients (CLL-023, CLL-024) with unfavorable prognosis had mutations both in BCR gene and in NOTCH2 gene of unknown significance. Conclusion: The data obtained from a pilot study demonstrate the possibility of using NGS technology in clinical practice. The assessment of the mutational status of pts with CLL using NGS correlates with the clinical parameters of pts. Considering that there is currently no information about prognostic significances of identified mutations, additional research is required. Disclosures Martynkevich: Pfizer: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau. Shuvaev:Pfizer: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Voloshin:Novartis: Honoraria, Speakers Bureau.

Assessment of the role of genetic abnormalities and minimal residual disease (MRD) is an active developing area in hematology. The use of genetic methods makes it possible to predict the course of the disease and apply an individualized approach to antimyeloma therapy. At the same time, the identification of MRD after therapy determines possibility of relapse. Aim. To identify the prognostic potential of MRD in patients in the standard and high molecular risk groups. Materials and methods. We analyzed 72 patients with MM (median age was 59 years (range 37-80), male/female - 1.3:1). All patients received initial therapy with proteasome inhibitors and / or immunomodulators. High dose therapy (MEL200) and autologous stem cell transplantation (ASCT) was carried out 50 (69%) patients. Standard cytogenetic and FISH methods were used to stratify patients in risk groups of mSMART 3.0. The standard risk (SR) was established in 52 (72%) patients, the high risk (HR) - in 20 (28%) patients. The MFC MRD status of bone marrow was evaluated after 4-6 cycles of induction therapy or after ASCT with use of 5-colors flow cytometry. MRD-negative status (MRD-) was based on level of clonal plasma cells Results. The MRD- was reached in 36% (26/72) patients. The median of OS in MRD+ group was 104 months, in MRD- was 146 months (p=.01). The median of PFS in MRD+ group was 26 months, in MRD- was 70 months (p=.00021). 2-years PFS in MRD+ group was 56%, in MRD- group was 100% (p=.00021). We divided patients into the following groups for evaluation the effect of MRD on survival in risk groups: SR МRD+ 34/72 (47%), SR МRD- 18/72 (25%), HR МRD+ 12/72 (17%) and HR MFC МRD- 8/72 (11%). The median of OS in HR MRD+ group was 72 months, in SR MRD+ - 104 months, in HR MRD- - 146 months, in SR MRD- was not achieved (p=.02). The median of PFS in HR MRD+ group was 24 months, in SR MRD+ - 26 months, in HR MRD- - 68 months, in SR MRD- - 70 months (p=.003). The 2-years PFS in HR MRD+ group was 44%, in SR MRD+ group was 50% and in SR MRD- and HR MRD- groups were 100% (p=.003). Conclusion. The absence of MRD is the most important prognostic factor. The leveling of negative effect of genetic abnormalities become possible when the MRD-negative response status is achieved. Presumably, this is due to the elimination of clonal plasma cells owing to the use of optimal antimyeloma therapy which is based on the risk stratification. Disclosures Martynkevich: Pfizer: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Shuvaev:Novartis: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau.

Introduction Duration of treatment with tyrosine kinase inhibitors (TKI) is an important favorable prognostic factor for treatment-free remission (TFR) and deep molecular response (DMR) in patients (pts) with chronic myeloid leukemia (CML). Aim To analyze the impact of first-line treatment duration with imatinib and 2G TKI on molecular relapse-free survival (MRFS) in CML pts with sustained DMR. Patients and methods In total, 174 CML pts in chronic phase with ≥3 years treatment duration and sustained DMR (MR4-MR5, BCR-ABL IS 0.1%). Median (Me) age of pts was 43 (range 21-86) years; 39% were males. Me TKI treatment duration was 86 months (IQR 57-125 mo), Me DMR duration was 45 (IQR 29-66 mo). Imatinib, 2G TKI in first-line and 2G TKI in second-line were discontinued in 116 (66.7%), 15(8.6%) (11 nilotinib, 3 dasatinib, 1 bosutinib) and 43 (24.7%) (34 nilotinib, 9 dasatinib) pts respectively. Results Me follow-up time after treatment cessation was 33 months (range 1-133). MRFS at 6, 12, 24 and 36 months was 62% (CI: 55-70%), 53% (CI: 45-60%), 50% (CI: 42-57%) and 48% (CI: 40-56%) respectively. Treatment duration and MR4.5 vs MR4 were significant for MRFS both in univariate (p=0.009 and p=0.015) and multivariate analysis (p=0.017 and p=0.037). No difference in 36 months MRFS was observed for imatinib (47% (CI: 42-60%)), first-line 2G TKI (59% (CI: 33-84%) p=0.58) and second-line 2G TKI (47% (CI: 32-63%) p=0.97) groups. However, significantly shorter treatment duration was observed in first-line 2G TKI group (Me=44 mo (IQR 40-52 mo)) vs imatinib (Me=93 mo (IQR 69-127 mo)), p Conclusion The 2G TKI as a first-line seem to be an effective option to reduce the treatment duration before TFR in CML pts although MRFS rate was not significantly improved in our study.

Context Tyrosine kinase inhibitors in third-line therapy (TKI-3L) in chronic-phase chronic myelogenous leukemia (CP CML) is effective in a portion of patients. Meanwhile, it is unclear which patients may benefit from TKI-3L. Objective To identify the factors affecting the outcome of TKI-3L therapy in CP CML. Design A retrospective study was conducted in five centers of St. Petersburg and Leningrad Region in 2019. All CP CML patients who ever obtained TKI-3L in these centers were included, except patients (pts) with complete cytogenetic response (CCyR). Results Seventy-three pts (male=26) with baseline median age 51 (25–88) were included in the study. There were 51 (70%) pts without any CyR, including 27 (37%) cases without complete hematologic response in baseline. For other patients, the best baseline cytogenetic response was minimal or minor (mmCyR) in 12 (16%) and partial (PCyR) in 10 (14%). BCR-ABL mutations were detected in 30/73 (42%) cases at any time before TKI-3L. Reasons for switching to TKI-3L were resistance in 56 (77%) or intolerance in 17 (23%). Dasatinib, Nilotinib, Bosutinib, or Ponatinib were used as TKI-3L in 43 (59%), 18 (25%), 9 (12%), and 3 (4%) pts, respectively. The median time of TKI-3L treatment duration was 15 (1–120) months. CCyR was achieved in 8/51 (16%) and 14/22 (64%) pts without CyR and with mmCyR/PCyR, respectively(p=0.001). CCyR subsequently had been lost 5/8 (62.5%) and 5/14 (29%) pts initially without or with any CyR (p=0.01). MMR was achieved in 3/51 (6%) and 6/22 (27%) pts without or with any CyR (p>0.05). Estimated overall 1-year, 3-year, and 5-year OS were 95%, 81%, and 65%, respectively. The median follow-up was 26 (3–136) months. There were 14 (19%) death: 11 due to CML progression and 3 after allo-SCT. All deaths occurred in pts without any CyR at baseline. Transformation to accelerated phase and blast crisis was occurred in 13 (18%) pts only in pts group without any CyR initially. The median time to progression was 15 (6–102) months. The only relevant baseline factor for CCyR, OS, and PFS probability in multivariant analysis was the presence of any CyR at baseline (p Conclusion Initial presence of any CyR was a favorable factor for long-term results of TKI third-line treatment in CP CML. TKI-3L should be considered as an appropriate tool in CML treatment for this group.

Background The risk-stratification systems are repeatedly updated in accordance with the emergence of new information about the prognostic impact of anomalies and other factors. The most extensive and modern system in this time is mSMART risk stratification involving many parameters such as genetic anomalies, albumin, beta-2-microglobulin, LDH, Plasma Cell S-phase and GEP levels. It is possible to use risk-adapted treatment programs with or without ASCT. Nevertheless, the role of complex karyotype, combination of genetic abnormalities and ASCT remains unclear. Aims To estimate the genetic abnormalities in patients with newly diagnosed multiple myeloma and define the role of risk-stratification and ASCT in prognosis of disease. Methods The study included 159 patients (median age 63 years, range 28 - 83; male: female ratio - 1:1.37) with NDMM. Metaphase cytogenetics on bone marrow samples was done by standard GTG-method. FISH analyses were performed according to the manufacturer's protocol for detection primary IgH translocations, 13q (13q14/13q34) deletion, 1p32/1q21 amplification/deletion, P53/cen 17 deletion (MetaSystems DNA probes). We additional searched the t(4;14), t(6;14), t(11;14), t(14;16) and t(14;20) in patients with IgH translocation. All patient was treated by bortezomib-based programs (VD, CVD, VMP, PAD). ASCT was performed at 42% patients. Results The frequency of genetic abnormalities in NDMM patients was 49% (78/159). IgH translocation was detected in 26.4% (42/159) patients: t(11;14) - 16.3% (26/159), t(4;14) - 5.0% (8/159); TP53/del17p - 5.6% (9/159); 1p32/1q21 amp/del - 12% (19/159); hypodiploidy - 3.1% (5/159); hyperdiploidy - 1.25% (2/159); del5q - 0,6% (1/159); other - not found. Combination two aberrations was discovered in 11.9% (19/159) patients, complex abnormalities (>3 aberrations) - in 4.4% (7/159) patients. The median OS in "two aberration" and "complex abnormalities" groups were lower than in standard-risk mSMART 3.0 (normal, t(11;14), hypodiploidy, hyperdiploidy and other): 49 months, 26 months and was not reached, respectively (p=.00015). The median PFS for these groups was 12 months, 11 months and 30 months, respectively (p=.011). Differences between "two aberration" and "complex abnormalities" groups were not find (p> .05). We modified high-risk (gain 1q, p53 mutation, del 17p deletion, t(4;14), t(14;16), t(14;20), R-ISS stage III, double and triple hit myeloma) mSMART 3.0 by adding "two aberration" and "complex abnormalities" groups on based the OS and PFS results. The final analysis was based on the results of the complex examination of 87 patients: 53 patients in standard-risk group and 34 patients in high-risk group. The median OS in standard-risk mSMART 3.0 was not reached, in high-risk mSMART 3.0mod - 48 months; 5-years OS was 62% and 38%, respectively (p=0.0073). The median PFS was 43 and 29 months, respectively (p=.09). The best results of OS and PFS were reach in both groups of patient who performed ASCT. The median OS in standard-risk mSMART 3.0 with ASCT (n=37) was not reached, in high-risk mSMART 3.0mod with ASCT - 48 months (n=20); standard-risk mSMART 3.0 without ASCT - 40 months (n=16); in high-risk mSMART 3.0mod without ASCT - 22 months (n=14); 5-years OS was 81%, 60%, 33% and 28%, respectively (p=0.0015). The median PFS was not reached, 46, 22 and 19 months, respectively (p=.017). Conclusions The combination of two aberrations and complex abnormalities is unfavorable prognostic markers. The median OS and PFS was higher in standard-risk than high-risk group according mSMART 3.0mod. The ASCT can improve treatment's outcomes and life expectancy especially in patients with high-risk. It can be useful for update risk stratification in a future. Disclosures Shuvaev: Novartis: Consultancy; Pfize: Honoraria; Fusion Pharma: Consultancy; BMS: Consultancy.

Introduction. There is strong evidence that the achievement of a negative status for minimal residual disease (MRD) is the single most important factor predictive of final outcome in patients with chronic lymphocytic leukemia (CLL) both in previously untreated and relapsed patients. Maintenance treatment (MT) with the CD20-directed monoclonal antibodies rituximab or ofatumumab yields better progression-free survival (PFS) compared with observation alone in individuals with CLL who have received induction therapy with chemo-immunotherapy. However maintenance therapy of anti-CD20 antibodies, although approved in some other B-cell malignancies, is not yet approved in CLL by regulators. Aim. We wanted to assess overall and progression-free survival in MRD-positive patients who received maintenance therapy. Methods. The study included 58 patients (median age 62 years, range 36-82). Male to female ratio - 1.7:1. We have used NCI revised guidelines (Hallek M, et al., 2008) for treatment initiation, assessment of response and MRD. Induction chemotherapy was conducted under the following programs: RB, RFC. The median line of therapy was - 1 (1-5). Evaluation of MRD was performed using 5-color flow cytometry of the bone marrow cells. The maintenance therapy was conducted MRD-positive patients (n=41): Rituximab 500 mg/m2 intravenously every 8 weeks for 2 years. The remaining MRD-negative patients (n=17) were under dynamic observation without therapy. Median observation in study was 51.5 month (15.2-134.8). Results.The frequency of relapses in the group of patients with MT was 51.2%, in the group of patients without MT - 70.6% (p=0.18). MRD was not detected after 6-12 months of MT in 17.1% (7/41) had previously MRD-positive patients. The medians of PFS and OS were not different in the MRD-positive patients with MT versus in the MRD-negative patients without MT: PFS - 45.9 months and 57 months, respectively (p=0.83); OS - 106 and 128 months, respectively (p=0.47). Significant differences in the incidence of infectious complications between patients with MT and without of MT were not detected (p˃0.05). Conclusions.Maintenance therapy for MRD-positive patients allows increasing of progression-free and overall survival to the level of patients with MRD-negative status. Maintenance therapy may be a means of control over the minimal residual disease and the method of its eradication. The proposed algorithm need further testing to confirm the initial results. Figure Disclosures Shuvaev: Novartis: Consultancy; Pfize: Honoraria; BMS: Consultancy; Fusion Pharma: Consultancy.

to investigate the methylation status of the SOX7 and p15NK4b genes and Wnt signaling pathway antagonists in patients with acute myeloid leukemia (AML) in order to assess the association of the rate of aberrant methylation (AM) with the morphological variant and pattern of chromosomal aberrations, as well as the impact of the methylation status on survival.The data of 57 AML patients aged 20 to 79 years were analyzed. The methylation status of the genes was studied by methylation-specific polymerase chain reaction.The signs of the AM of ≥1 gene were detected in 52 (91.2%) of the 57 patients. The most common finding was AM of simultaneously 2 or 3 genes: in 29.8 and 21.1% of the patients, respectively. Concurrent methylation of 3-5 genes proved to be a more frequent finding in AML patients with myelodysplasia: in 7 (70%) of 10 patients. The proportion of patients with methylation of 5 genes was considerably higher in a group of patients with a complex karyotype: 50% versus 8.3% among other patients (odds ratio: 11.0; 95% confidence interval 2.0 to 61.6; p=0.01). There were no differences in the median overall and relapse-free survival rates in patients with a normal karyotype and without FLT3 and NPM mutations, who received induction therapy, in relation to the number of genes with AM.AM of the p15NK4b and SOX7 genes and Wnt signaling pathway antagonists is detected in the majority of patients with AML, which allows hypomethylating agents to be recommended for the treatment of patients who cannot use intensive cytostatic therapy for different reasons. The detection of a large number of genes with the aberrant methylation status in most AML patients with myelodysplasia or a complex karyotype serves as the basis for initiating trials to evaluate the efficiency of a combination of 5-azacytidine and cytostatics.Цель исследования. Изучение статуса метилирования генов SOX7, p15INK4b и антагонистов сигнального пути Wnt у больных острым миелоидным лейкозом (ОМЛ) для оценки сопряженности частоты аберрантного метилирования (АМ) с морфологическим вариантом и характером хромосомных аберраций, а также влияния статуса метилирования на выживаемость больных. Материалы и методы. Проанализированы данные 57 больных ОМЛ в возрасте от 20 до 79 лет. Статус метилирования генов изучали посредством метилспецифической полимеразной цепной реакции. Результаты. Признаки АМ≥1 генов выявлены у 52 (91,2%) из 57 больных. Наиболее частой находкой было АМ 2 или 3 генов одновременно: у 29,8 и 21,1% больных соответственно. Одновременное метилирование 3-5 генов оказалось более частой находкой у больных ОМЛ с миелодисплазией - у 7 (70%) из 10. Доля больных с метилированием 5 генов значительно выше в группе с комплексным кариотипом: 50% против 8,3% среди других больных (отношение шансов 11,0 при 95% доверительном интервале от 2,0 до 61,6; p=0,01). Не выявлено различий по медиане общей и безрецидивной выживаемости у больных с нормальным кариотипом и без мутаций генов FLT3 и NPM, получавших стандартную индукционную терапию в зависимости от числа генов с АМ. Заключение. АМ генов p15INK4b, SOX7 и антагонистов сигнального пути Wnt обнаруживается у большинства больных ОМЛ, что позволяет рекомендовать гипометилирующие препараты для лечения больных, которым по разным причинам не может быть назначена интенсивная цитостатическая терапия. Обнаружение у большинства пациентов с ОМЛ с миелодисплазией или комплексным кариотипом значительного числа генов с аберрантным статусом метилирования служит основанием для инициации исследований по оценке эффективности комбинации 5-азацитидина с цитостатиками.

Secondary myeloid neoplasia may be a complication of intensive cytostatic therapy. The most common types of secondary neoplasias are acute myeloid leukemia and myelodysplastic syndrome. The development of secondary atypical chronic myeloid leukemia (aCML) is an extremely rare phenomenon. The paper describes transformation of secondary myelodysplastic syndrome to aCML 6 months after its diagnosis. The development of aCML was accompanied by additional chromosomal aberration as monosomy of chromosome 17. No mutations in the JAK2, MPL, and CalR genes were detected. It is concluded that the clinical course of secondary myeloid neoplasias is variable.Осложнением интенсивной цитостатической терапии может быть развитие вторичной миелоидной неоплазии. Наиболее частыми вариантами вторичных неоплазий являются острый миелоидный лейкоз и миелодиспластический синдром. Развитие вторичного атипичного хронического миелолейкоза (АХМЛ) - крайне редкое явление. Приведено описание трансформации вторичного миелодиспластического синдрома через 6 мес после его диагностики в АХМЛ. Развитие АХМЛ сопровождалось дополнительной хромосомной аберрацией в виде моносомии 17-й хромосомы. Мутаций в генах JAK2, MPL и CalR не выявлено. Сделано заключение о вариабельности клинического течения вторичных миелодных неоплазий.

Background. The treatment of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors (TKI) have diminished death probability and have changed the disease course. Achievement of complete cytogenetic response (CCyR) and major molecular response (MMR) are serve as warranties for freedom of progression and death from CML. There are many of CML patients are needed to change of initial TKI therapy with choice of the most efficient and safe drug for continuous life-long therapy to reach the optimal results of CML treatment. The newest of registered TKI drug in Russia is Bosutinib which has dual BCR-ABL and SRC kinase inhibitory activity and had showed good tolerability and efficacy in case of other TKIs resistance or intolerance. Aim. To analyze of own Bosutinib experience in patients with chronic myeloid leukemia with other TKIs resistance or intolerance and to make comparison with clinical trial results. Materials and methods. Clinical trials results from peer-reviewed journals. Outpatients charts of 51 patients (25 male and 26 females) with CML. Disease phase at the moment of Bosutinib therapy initiation was as follows: chronic - 37; acceleration - 8, blastic - 6. Bosutinib was used in the next lines of TKI therapy: second - 10; third - 18; fourth - 23. The indications for Bosutinib therapy were: intolerance to previous TKI - 21; resistance to previous TKI - 30. Results. Median of therapy duration was 6 months (1-50 months). The adverse events and tolerability of Bosutinib were similar with clinical trials data. The treatment was withdrawn by the adverse event only in 5 (10%) patients. The rates of the responses in the whole group of patients were as follows: CHR - 88%, stable in 76%; CCyR - 39%, stable in 37%, MMR - 31% and was 25% at the last follow-up. The Bosutinib efficacy in real life settings was slightly higher than clinical trials data. The factors influencing treatment responses were: disease phase, cause of switching to Bosutinib, line of therapy and presence and kind of BCR-ABL mutations, Therapy was continued in 22 (43%) patients, most them achieved stable optimal treatment response (CCyR and MMR). Conclusions. Bosutinib is a real alternative to other tyrosine kinase inhibitors and has its own mechanism of action and adverse events profile. The use of Bosutinib in real life clinical practice settings showed its efficacy and tolerability and could serve as base for recommendation to apply Bosutinib in hematology practice in Russia. Disclosures No relevant conflicts of interest to declare.

Background. The Atypical Chronic Myeloid Leukemia (aCML) and Chronic Neutrophilic Leukemia (CNL) had put in separate sections of myeloid neoplasms classification but have common entity and bone marrow changes. aCML and CNL hard to differentiate from each other. The main differential criterion is the proportion of immature white blood cells in blood, but it is not strong due to its instability. The achievement of recent years is discovering of aCML and CNL molecular factors: mutations in SETBP1 and CSFR3R genes gave the basis for the diagnosis confirmation in part of patients but could not differentiate between two nosologies. In addition, the access to the "uncommon" molecular diagnostic is complicated in routine clinical practice. Aim. At the abstract we would like to report the first, as we known, diagnosis of aCNL in Russia, that had been confirmed by molecular markers and is treating with target therapy. Materials and methods. The patient, female 51-year old has presented severe fatigue, pain, weight loss and burden under the left costal margin since Sep-2017. Results. The initial assessment has revealed massive splenomegaly (200x130x248 mm) with high WBC (133.9x109/L with left shift: blasts 1%, promyelocytes 6%, myelocytes 14%, metamylocytes 16%, bands 14%, segments 45%, lymphocytes 2%, monocytes 0%), mild anemia (10.4 g/dL) and normal platelets (223x109/L). There was neutrophil hyperplasia without eosinophilia and basophilia in myelogram. Initial diagnosis of typical CML was made but cytogenetic was normal and BCR-ABL (p190, p210) was negative. Atypical CML was suspected by bone marrow histology that demonstrated hypercellularity, granulocytic hyperplasia and mild megakaryocytic atypia and only mild reticuline fibrosis (MF-1). There were no MPN-driver markers (JAK2, CALR, MPL) revealed. Initial therapy with Hydroxyurea 2 g/day was started in Nov-2017. The re-work-up (morphological, cytogenetic, FISH and molecular) has been done in federal referral center in Nov-2017 but no signs of typical CML or Ph-MPN was detected. Mutation in exon 12 of ASXL1 gene was revealed in Jan-2018. After initial cytoreduction at follow-up in Feb-2018 mild leukocytosis (10.0-25.0x109/L) with shift to myelocytes and splenomegaly (+3 cm) was noted, severe fatigue and night sweats were still presented. Given the molecular results the target therapy with Ruxolitinib 15 mg BID was started since Feb-2018. The Ruxolitinib has given results with rapid resolution of constitutional symptoms, weight gain and complete CBC normalization during first month of therapy. At 3 months of treatment follow-up bone marrow histology showed hypocellularity and myeloid swelling. The first assessment of CSF3R gene in Russia on May-2018 has revealed the T618I mutation. Thus, the final diagnosis of aCML has been made (revealed mutation more related to CNL but WBC profile is consistent to aCML). The patient is still receiving Ruxolitinib therapy with complete clinical and hematologic response up to date. The search of unrelated donor was started. Conclusions. Nowadays diagnosis of aCML or CNL need to be established on thorough complex investigation. There is a need to get a widespread consensus guideline of aCML and CNL diagnosis and management and reclassification of these diseases in one common group. Disclosures No relevant conflicts of interest to declare.

Background: Thrombosis in Primary Myelofibrosis (PMF) is one of the main but not fully covered problem. Thrombotic complications in PMF occur more frequently than in general population and could result to morbidity and lethality of patients. Several previous studies have demonstrated different thrombotic rates related to type molecular driver mutation (JAK2V617F, CALR, MPL) in myeloproliferative neoplasms, but this fact now is not fully understood. The standard clotting tests cover only initial stages of coagulation and could not evaluate anticoagulant system. Its results are not varied in PMF patients with different mutations. We have interested and initiated study of the coagulation system in PMF patients with integral hemostasis test - Calibrated Automated Thrombography (CAT). Here we present the results of pilot study group assessment. Aim: to investigate of the coagulation system in PMF patients with different molecular driver mutations (JAK2V617F, CALR, MPL) using thrombin generation test. Methods: The study included 13 MF patients (26 - 71 years, median = 40). There were 11 females and 2 males. Nine patients were JAK2V617F positive, 3 had CALR mutations and one patient was MPL-mutated. Thrombin generation was assessed by calibrated automated thrombinography (CAT) according to Hemker et al. Assessments were conducted in platelet poor plasma (PPP) with or without presence of thrombomodulin (PPP reagent +/- TM) as an activator of protein C system. The following parameters were evaluated: endogenous thrombin potential (ETP, nM*min), peak thrombin (Peak, nM), lag-time (Lag, min), and time to peak (TTP, min). Sensitivity ETP and Peak for TM were calculated as percent of decreasing of these parameters after adding to assay of TM (S ETP, % and S Peak, % respectively). STATISTICA 6.0 package was used in data analysis. Results were presented as median (Me) with 95% confidence intervals (CI). Results: ETP was highest in JAK2V617F patients (1213.57; min 781.60-max 1781.26 nM*min), intermediate in CALR (1058.47; min 933.14-max 1190.79 nM*min) and lowest in MPL group (972.49 nM*min). However, the Peak was higher in CALR (207.57; min 165.63-max 235.36 nM) than in JAK2V617F (160.9; (min 94.38-max 317.11 nM) and MPL (136.19 nM). We have observed disruption of protein C functioning in JAK2V617F (S-ETP 34%, min 8.65%-max 68.73%; S-Peak 20%, min 0.01%-max 44.64%) and MPL (S-ETP 46%; S-Peak 24%) groups compared to CALR patients (S-ETP 6.4%, min 2.5%-max 9.2%; S-Peak 1.8%, min 0.87%-max 1.8%). Conclusion: The results of thrombin production were differed in relation to driver mutation type. JAK2V617F-patients produced more thrombin and have protein C system dysfunction. It could be serve as an explanation of higher risk of thrombosis in MF patients with JAK2V617F mutation. The yielded results force us to continue research to confirm our findings on representative sample of PMF patients. Disclosures No relevant conflicts of interest to declare.

Background: The paradigm of the treatment mantle cell lymphoma (MCL) has changed due to development of newer agents (such as ibrutinib, lenalidomide, temsirolimus). Considering that the scheme of using the newer drugs implies permanent drug intake (before disease progression), which helps prevent the early relapses. With a high degree of probability, it can be assumed that MCL, in the future can be withdrawn from the group of aggressive and relapsing lymphomas. Evaluation and monitoring of the minimal residual disease (MRD) in patients with MCL allows to predict the course of the disease and optimize the strategy for maintaining this category of patients. Aim: To assess influence of MRD negative (MRDneg) status on the duration of progression free survival (PFS) and overall survival (OS). Method: In this study were included 33 patients with MCL (male/female ratio 3:1), age 51 to 82 years (median 64 years). The median of follow-up duration is 80.7 months (range 0.7-147.1). Median of therapy lines - 1 (range 1-5). With rituximab-containing chemotherapy regimens were treated 25 patients (R-CHOP - 12, RFC - 5, RBV - 3, RB - 2, R-DHAP - 1, R-Hyper-CVAD - 1, RVc-CAP - 1); ibrutinib - 3, lenalidomide - 3 and temsirolimus - 1. Autologous stem cell transplantation (AutoSCT) was performed in 7 patients (21.2%). Maintenance therapy received 23 patients (69.7%): rituximab - 20, ibrutinib - 1, lenalidomide - 1 and temsirolimus - 1. During the follow-up period, 9 patients (27.2%) died: progression of the disease - 5, other reasons - 4. The evaluation of MRD status was carried out using 5-color flow cytometry on bone marrow samples after completion of induction therapy. The absent of MRD was detected when less than 1 tumor cell was detected per 10000 leukocytes (10-4). Results: Complete remission (CR) was achieved in 54.5% (n=18), partial remission (PR) - 45.5% (n=15). Patients were divided into two groups depending on MRD status: group MRD positive (MRDpos) (n=12) and group MRD negative (MRDneg) (n=21). The frequency of achievement of MRDneg status was 63.6% (CR - n=15, PR - n=6). Noted, that all patients (n=7) who underwent AutoSCT achieved MRDneg status after induction therapy and kept it after consolidation with AutoSCT. Disease progression in MRDpos group was state in 11 patients (91.7%), in MRDneg group - 6 (28.6%) (р=0.0005). Patients with MRDpos status who underwent maintenance therapy achieved MRDneg status in 8/12 cases. One patient, after completion R-CHOP + AutoSCT followed by a two-year maintenance program of rituximab, retained MRDneg status. A year later, during the control survey, MRDpos status was recorded. This patient was resumed maintenance therapy with rituximab. MRDneg status is achieved after 6 months from the beginning of maintenance therapy. Median PFS in group MRDneg was not achieved, in group MRDpos - 12.5 months (р=0.001). Medians OS were not achieved in both groups. 5-year OS were: group MRDneg - 83.8% and group MRDpos - 73.3%. 10-year OS were: group MRDneg - 64.4% and group MRDpos - 58.7%. When comparing OS in patients among all groups no significant differences were found, which is probably due to a small number of events (р>0.05). Conclusion: Our data demonstrate that achievement MRDneg remissions determine duration of response on ongoing therapy and significant increase of PFS duration. Presently, MRD detection in patients with MCL is important part of complex assessment of effectiveness therapy and it need to be studied more. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

This rare type of acute leukemia, blast cells of which express myeloid and/or lymphoid markers, is mainly diagnosed using flow cytometric findings. The paper describes a clinical case of mixed-phenotype acute leukemia, in which B-cell lymphoid antigen expressions were revealed by a flow cytometric technique, while bone marrow morphological specimens showed the signs of myeloid differentiation specific to blast cells. It is concluded that there is a need for a comprehensive examination of patients with new-onset acute leukemia and for an aggregate analysis of flow cytometric results with morphological and cytochemical findings.Диагностика редкого варианта острого лейкоза, бластные клетки которого экспрессируют миелоидные и/или лимфоидные маркеры, осуществляется преимущественно по данным проточной цитометрии. Приведен клинический случай острого лейкоза со смешанным фенотипом, при котором методом проточной цитометрии выявлена экспрессия В-лимфоидных антигенов, в то время как в морфологических препаратах костного мозга обнаружены признаки, типичные для бластных клеток миелоидной направленности. Сделано заключение о необходимости комплексного обследования больных с впервые выявленным острым лейкозом и совокупным анализом результатов проточной цитометрии с данными морфологического и цитохимического исследований.

Background. The tyrosine kinase inhibitors (TKI) are the standard therapy for patients with chronic myeloid leukemia (CML) in chronic phase. However, six years after the diagnosis, only 50%-60% of CML patients are treated with the initial dosage of Imatinib, while the remained patients require a different dosage or treatment. One of the causes of resistance to TKI is additional chromosome aberrations in Ph+ cells (ACA) and BCR-ABL1 kinase domain (KD) mutations. Patients with KD mutations, (especially with mutations affecting P-loop and T315 codon) and patients with ACA in addition to the Ph-chromosome have significantly inferior unfavorable outcomes. To the best of our knowledge, the presence and the prognostic role of the two major resistance mechanisms in CML patients during TKI treatment had not been performed in combination before. The aim of our study was to evaluate the long-term impact of the simultaneous presence of BCR-ABL1 KD mutations and ACA in Ph+ cells in newly diagnosed CML patients on TKI treatment results. Patients and methods.We analyzed charts of 30 patients with ACA in Ph+ cells, who were diagnosed with CML between 2005 and 2015. All patients received only TKI treatment. There were 14 females (47%) and 16 males (53%) with a median age of 47 years (range, 20-75). Patients' distribution for Sokal risk groups was as follows: low 6 (20%), intermediate 10 (33%), high 14 (47%) patients. Five (17%) patients had high-risk EUTOS score. Twenty-three patients had been diagnosed in the chronic phase and 7 (23%) - had the accelerated phase. Twenty-six (87%) patients started treatment with Imatinib 400 mg QD, 3 patients started with Nilotinib 400 mg BID and 1 patient started with Dasatinib 100 mg QD. The "major-route" ACA was detected in 16 (53%) CML patients. Sixteen (53%) patients had ACA at the time of initial CML diagnosis. We investigated the influence of ACA and KD mutations on overall survival (OS) and CML-related death with the Cox regression method and Fine and Gray regression model. Probabilities of OS were estimated using the Kaplan-Meier method, survival times were compared with log-rank test. Cumulative incidence probability (CIP) of "death due to CML" were estimated with cumulative incidence function (causes of death unrelated to CML had to be considered as competing risks), difference between groups was assessed with Gray's test. All analyses were performed according to the intention-to-treat principle. Results. The median follow-up from diagnosis was 77 months (range, 14-124), from ACA emergence - 51 months (3-124). Six (20%) patients died at the moment of the analysis data, 5 (17%) of them had CML progression. The combination of BCR-ABL1 KD mutations and ACA (ACA+mut) was found in 6 (20%) patients. Five different mutations (T315I, E355G, G250E, D363Y, E279K) were identified and one patient had double mutations (F359C and T315I). Forty-six percent (12/26) of Imatinib first-line treated patients were switched to second-line therapy (Dasatinib and Nilotinib), subsequently 12% (3/26) of patients were switched to Dasatinib as third-line. Among the 2nd TKI first-line treated patients: 2 (50%) were switched from Nilotinib to Dasatinib. The multivariate regression analysis had shown that the combination of BCR-ABL1 KD mutations with ACA had a prognostic significance for OS (p=0.003) and a cumulative incidence of death due to CML (p=0.0005) from the moment of ACA emergence. We also studied the influence of these factors influence on OS and CIP of death due to CML from date of diagnosis. ACA+mut co-existence (n=6) was statistically significant (p=0.02) only for CIP of death due to CML, but not for OS. On the next step, we compared the impact of combination BCR-ABL1 KD mutations with ACA on OS and CIP death due to CML following the emergence of ACA. As shown in Figure 1, patients with ACA+mut (n=6) had a lower 4-year survival rate (28%) than patients with only ACA - 95% (n=24), p Conclusion. Our study demonstrated the significance of simultaneous presence of BCR-ABL1 KD mutations and ACA for TKI therapy outcome. CML patients with a combination of BCR-ABL1 KD mutations and ACAs conferred an inferior survival and can be viewed as the poor prognostic group. Figure 1 Figure 1. Disclosures Fominykh: Novartis Pharma: Honoraria; BMS: Honoraria. Shuvaev:Pfizer: Honoraria; BMS: Honoraria; Novartis pharma: Honoraria. Shukhov:Novartis Pharma: Honoraria; BMS: Honoraria. Chelysheva:Novartis: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau. Turkina:Pfizer: Honoraria; Novartis Pharma: Honoraria; BMS: Honoraria.

Introduction . The development of Bruton's tyrosine kinase inhibitors and their introduction into clinical practice represent a major advance in the treatment of chronic lymphocytic leukemia (CLL). Several studies in CLL have determined the achievement of minimal residual disease (MRD) negativity as an independent favorable prognostic factor, associated with superior progression-free survival (PFS) and overall survival. MRD status is the single best posttreatment predictor of long-term outcomes after treatment, regardless of the treatment protocol or the presence of other pre-existing prognostic indicators. Aim.To estimate of response rate, PFS and MRD after ibrutinib-based therapy in the treatment patients with relapsed/refractory CLL. M ethods.21 pts with relapsed/refractory CLL were included in the analysis. Stratification of patients into groups based on therapy. Group 1 (n = 14): 2nd and subsequent lines of rituximab-based chemotherapy (RB - 10, FCR - 4) and Group 2 (n = 12): ibrutinib-based therapy (420 mg daily oral Ibrutinib ± Chemoimmunotherapy). We have used NCI-IWCLL revised guidelines for treatment initiation and assessment of response. MRD was detected by multicolor flow cytometry of bone marrow in patients achieved a complete or partial remission: Group 1 - 7 pts, Group 2 - 5 pts. Results. The median age was 60.5 years (45-83) in Group 1 and 62.5 years (49-82) in Group 2 and median previous lines of therapy was 1 (1-4) and 2 (1-4), respectively. Patients with unfavorable chromosomal abnormalities were detected in each group: Group 1 - 2 pts (combination del(11q) with del(13q)); Group 2 - 1 pts (del(17p)). Overall response rate (ORR) in Group 1 was 71.4% (complete remission (CR) - 1 pt, partial remission (PR) - 9 pts, stable disease (SD) - 3 pts, progression disease - 1 pt). Group 2: ORR 91.7% (CR - 3 pts, PR - 8 pts; SD - 1 pt). Statistically significant differences in the frequency of ORR between groups were not detected (p>0.05). MRD-negative remission rate was 40% (2/5, CR - 1 pt) in Group 2 compared to 14.3% (1/7 pts, CR) in Group 1 (p>0.05). Statistically significant differences in PFS were detected between Group 1 vs. Group 2 (p=0.0006). Median PFS in Group 2 has not been reached. Median PFS in Group 1 was 16.9 month. Conclusion. Ibrutinib is highly effective at controlling disease, but best responses are typically partial remission, and patients must remain on treatment to maintain disease control. Evaluation of response and MRD after ibrutinib-containing therapy in the treatment of patients with relapsed/refractory chronic lymphocytic leukemia require further research. Disclosures Shuvaev: Pfizer: Honoraria; BMS: Honoraria; Novartis pharma: Honoraria.

Introduction. A generic drug is a pharmaceutical drug considered to be equivalent to a brand-name product. A generic drug has to contain the same active ingredients as those of the original formulation. Regulatory agencies used to require that generics be identical to their brand-name counterparts with regards to pharmacokinetic properties. In most cases, generic products are available after the patent protection given to a drug's original developer expires. In Russia, a patent protection lasts for a 10-year period from registration of the original drug. To this day, twelve Imatinib generics have been registered in Russia. Aim. To assess the safety and efficacy of Imatinib generics for treatment of newly diagnosed Chronic myelogenous leukemia patients that have been in our center since August 2012. Materials and methods. 30 newly diagnosed CML patients were started on generics. The drugs: 1) GenericPh 100 mg, in capsules (Ph-Syntez, Russia); 2) GenericG 100 mg, in tablets (Laboratorio TUTEUR S.A.C.I.F.I.A., Argentina); 3) GenericIm 100 mg, in tablets (Sandoz d.d. (Slovenia). Switching from one generic to another was done due to intolerance. We analyzed the range and frequencies of adverse events (AE), cumulative incidences of complete hematologic (CHR), major cytogenetic (MCyR), complete cytogenetic (CCyR), and early molecular responses (BCR-ABL Results. Duration of the treatment with generics was 7-45 months, with a median of 13 months (GenericPh (27) + GenericG (2) + GenericIm (1)). No unexpected adverse events were observed during the Imatinib generics treatment. The generics tolerance did not differ from that of the original brand-name drug. Six patients were switched to second-generation tyrosine kinase inhibitors (TKI2) due to Imatinib intolerance. One patient progressed to blastic phase at 3 months after diagnosis. Three deaths were registered (1 - due to CML and 2 due to concomitant diseases). Overall survival rate was 90% and CML-related mortality - 3%. CHR at 3 months of the treatment was achieved in 93% of the patients. Cumulative response rates for cytogenetic and molecular responses are presented in Table 1. MR4.0 was registered in 23% of patients during overall treatment. Seven patients were switched to TKI2 due to insufficient efficacy of Imatinib. At the time of analysis 13 patients remained on Imatinib generics treatment: 12 patients with CCyR and 1 with PCyR, including 10 patients with MMR. Conclusion. Use of generics demands evaluation of its equivalency and control during its adoption into clinical practice. In terms of efficacy or tolerance no significant differences between the Imatinib generics studied and the original brand-name drug in newly diagnosed CML patients were found. Disclosures Shuvaev: Pfizer: Honoraria; BMS: Honoraria; Novartis pharma: Honoraria. Fominykh:BMS: Honoraria; Novartis Pharma: Honoraria.

Introduction. The substitution of brand-name drugs with cheaper generics is a modern tendency in health-care to decrease the burden on government budget and improve access to efficient treatment. Worldwide, generics have to be identical to the original drug in terms of pharmaceutical (active ingredients) and biological (pharmacokinetic) properties. Unfortunately, in Russia, as in most countries, there are no government regulations of equivalency to a brand-name product regarding dosage, strength, route of administration, quality, performance, and intended use. In Russia, since August 2012 the original Imatinib has almost fully been substituted with generics for the treatment of chronic myelogenous leukemia (CML). Aim. To assess tolerance and efficacy of Imatinib generics in terms of response durability by comparing it with that achieved previously in CML patients, who had received treatment with original Imatinib before switching to the generics. Materials and methods. Seventy-nine CML patients treated initially with original Imatinib (Novartis AG) with median treatment duration of 6.5 years (range, 0.5-11 years) were switched to generic drugs. The drugs: 1) GenericPh 100 mg, in capsules (Ph-Syntez, Russia) - 54 patients (44 with complete cytogenetic response (CCyR), including 32 with major molecular response (MMR); 2) GenericG 100 mg, in tablets (Laboratorio TUTEUR S.A.C.I.F.I.A., Argentina) - 25 patients (22 with CCyR, including 19 with MMR). In case of loss of response, besides non-compliance, we changed treatment to second-generation tyrosine kinase inhibitors (TKI2). Switching from one generic to another was made due to intolerance. We analyzed the range and frequency of adverse events (AE) and durability of responses achieved previously (hematologic, cytogenetic and molecular). IRIS data1 was used as a comparator for AE frequency during long-term Imatinib treatment. Statistical analysis included the Fisher exact test. Results. Tolerance of Imatinib generics was good with few exceptions. One patient in the GenericPh group suffered severe edema and was switched to Nilotinib with AE resolution. In the GenericG group 4/25 (16%) patients had severe gastroenterological toxicity (nausea, vomiting, abdominal distension, diarrhea) and were successfully switched to GenericPh. This might have been caused by the tablet filler (lactose) and related to concomitant lactose insufficiency in these patients. One patient had frequent infectious complications. Having stable deep molecular response, she entered the treatment free remission phase and had successful molecular response for more than two years. The frequency of other AEs is presented in Table 1. No significant differences were revealed between the generics and the original Imatinib in comparison with IRIS results. However, only 25% (20) of patients were free of any AE. No progression to AP/BC during the generics treatment was observed. Three deaths were registered (CML-related 1, blastic phase on Dasatinib treatment, the patient had only partial cytogenetic response to Imatinib and was switched to Dasatinib, with progression after 2 years on Dasatinib; cancer -1, cardiovascular disease -1). The patients who had inadequate responses to Imatinib before and after switching on generics were subsequently switched to TKI2: GenericPh - 11 patients (Nilotinib - 9 (CCyR - 8, MMR-7), Dasatinib - 2 (no CCyR with progression - 1, complete hematologic response -1)); GenericG - 3 patients (Nilotinib - 2, both with CCyR and MMR, Dasatinib - 1 -hematologic response with non-compliance). Durability of previousresponses was as follows: 4 patients lost their MMR: 3/54 (5.6%) while taking GenericPh and 1/25 (4%) - GenericG; 3 patients lost their CCyR: 2/54 (3.7%) while taking GenericPh and 1/25 (4%) - GenericG. All those patients were subsequently switched to TKI2 (3 re-achieving previous MMR and 1 demonstrating non-compliance). At the time of analysis there were still 58 (73%) patients on the generics treatment. 57 patients had CCyR and MMR, and one was not cytogenetically evaluated due to non-compliance (BCR-ABL 0.102%). Conclusion. No significant differences between the generics studied and the original Imatinib were observed in terms of their efficacy or tolerability in CML patients who were previously treated with a brand-name drug and subsequently switched to generics. Disclosures Shuvaev: Novartis pharma: Honoraria; Pfizer: Honoraria; BMS: Honoraria. Fominykh:Novartis Pharma: Honoraria; BMS: Honoraria.

Background. The presence of the JAK2V617F mutation is a major criterion in diagnostic of Polycythemia Vera (PV). The role of JAK2V617F allele burden in the progression of PV is not completely understood. The significance of this variable for the progression of the disease, complications development and response to therapy are still a big question mark. Aim. To estimate the significance of the level of JAK2V617F allele burden in the treatment of PV. Methods. Seventy-nine patients (pts), 48 females and 31 males, were included in the study. PV was diagnosed from 1980 to 2016. Median age was 61 years (range, 28 - 85), median of the observation period was 4.9 year (0,2 - 35 years). JAK2V617F allele burden was studied in all pts. Patients received therapy with phlebotomy (erythrocytapheresis), hydroxyurea, interferon-alpha or combined therapy. Hematological response to the therapy was evaluated according to ELN criteria[1]. Differences between the groups were assessed with the Mann-Whitney U test. Results. Out of the 79 patients, complete hematological response (CHR) was achieved in 8 (10%) pts, partial response (PHR) in 48 (60.8%) pts, and no response was achieved (no response - NR) in 23 (29,2%) pts. The mean level of allele burden in the group of patients with PHR was 68%(CI 57%-79%), in that without response - 65%(CI 43%-86%), and in the group with CHR was 35% (CI 19%-50%). The JAK2V617F allele burden was significantly different between the groups with CHR and PHR (p Conclusion. The level of JAK2V617F allele burden can be a predictive marker of a response to treatment of PV. An individual approach to each patient, including a detailed study of molecular factors, is the key to successful prevention of complications and ensuring positive outcomes. [1] Barosi G, Birgegard G, Finazzi G, et al. Response Criteria for Essential Thrombocythemia and Polycythemia Vera: Result of a European LeukemiaNet (ELN) Consensus Conference. Blood. 2009 Mar 10 Figure The JAK2V617F allele burden levels in patients groups by treatment response. Figure. The JAK2V617F allele burden levels in patients groups by treatment response. Disclosures Shuvaev: Novartis pharma: Honoraria; Pfizer: Honoraria; BMS: Honoraria. Fominykh:Novartis Pharma: Honoraria; BMS: Honoraria.

Background. Induction, consolidation of response and maintenance therapy are very effective approaches in the treatment of patients with multiple myeloma (MM). However, the majority of patients will inevitably relapse despite achieving progressively higher complete response (CR) rates. Activation of residual clonal plasmatic cells is a cause of relapse disease. Therefore, the assessment of minimal residual disease (MRD) is a strong prognostic factor for progression-free survival (PFS). Aim. To estimate influence of MRD on PFS indicators in MM patients. Methods. We analyzed 28 patients with MM (median age 56 years, male/female - 1.8:1). 5-color flow cytometry was used for immunophenotyping of bone morrow cells as well as definition of primary tumor cells phenotype and detection of MRD. Such markers as CD38, CD138, CD45, CD19, CD20, CD27, CD56 and CD117 were used to identify clonal plasma cells. In addition, MRD was assessed by FISH analysis in patients with genetic abnormalities; CT-PET carried out to patients with the MRD-negative CR. Results. Patients had bortezomib- or lenalidomide-based programs of therapy. Autologous stem cell transplantation (ASCT) was carried out in 18 patients. Performing ASCT statistically significantly increased frequency of MRD-negative CR (p.05). PFS in the MRD-negative group was better than in the MRD-positive group with CR (median was not reached vs median of 63.9 months, respectively; 2-year PFS was 100% vs 77%, respectively) (p=.0048). In addition, we analyzed the influence of CR in the MRD-positive group on PFS. Absence of CR is an inferior prognostic factor and is characterized by decrease of PFS in patients with MRD-positive status. The median PFS in the MRD-positive group with CR was 63.9 months and 26.0 months in the MRD-positive group without CR (VGPR and PR) (p=.049). Genetic abnormalities were detected in 7/26 (26.9%) patients before antimyeloma therapy: t(11;14) - in 5/26 (19.2%), del(13q) - in 3/26 (11.5%), t(4;14) - in 1/26 (3.8%), del(1p) - in 1/26 (3.8%). After treatment patients with CR (MRD-positive and MRD-negative) had normal genetic status by FISH. Only 1/7 patients with MRD-positive PR had residual clone with del(13q). Conclusion . Performing ASCT influences frequency of MRD-negative CR. The PFS indicators (median and 2-year PFS) were higher in the group of MM patients, who had MRD-negative status of the disease compared to than in the MRD-positive group. The FISH method had low sensitivity in detection of residual clone with genetic abnormalities, especially in patients with CR. Disclosures Shuvaev: BMS: Honoraria; Pfizer: Honoraria; Novartis pharma: Honoraria.

Introduction. Implementation of target therapy in chronic myelogenous leukemia (CML) treatment allowed saving life for majority of CML patients. First and second generation tyrosine kinase inhibitors (TKI) usage experience showed that part of patients can achieve deep molecular responses. Clinical trials of treatment cessation in CML patients with deep molecular response demonstrated that substantial proportion of patients can be free from drug with predictable relapse risk and safe treatment re-initiation. This approach is interesting due to sustained increasing number of CML patients and avalanche like increment of budget burden because of continuous expensive TKI therapy. The aim of our study was to assess potential budget impact of successful TKI cessation in CML patients with long-lasting deep molecular response. Materials and methods. Pharmacoeconomical modelling of CML diagnostic and treatment process including treatment free remission (TFR). Markov chain approach was implemented to construct models for non-stop therapy and TFR in patients with sustained molecular response 4 logs (MR4.0) (Fig 1). Treatment re-initiation was considered in case of major molecular response loss. The total number of CML patients in Russia was 6500; annual rate of newly diagnosed CML cases was 800 (in accordance with Russian CML Registry data). The patient consent rate to TFR inclusion was assumed as 80%. Transition rates were chosen from clinical trials and own experience. Cost-utility analysis of first and second generation TKI apply was performed. Simulation of clinical and economical consequences was done on national level. Five-year (2015-2020) time horizon was used. To simplify presentation of our results we recalculated costs to US dollars. Results. Our analysis showed that by year 2020 the estimated total CML patient number in Russia will be about 11000 patients with total direct yearly CML cost 109 mln $. TFR approach can decrease budget burden from 109 to 95 mln $ yearly and the total evaluated money saving during years 2015-2020 period in Russia will be 67 mln $ with complement cost-utility data (Fig 2). Conclusion. Annual CML cost will increase due to increment of CML patients number. Nevertheless, TFR strategy in CML patients with long-lasting deep molecular response under continuous molecular monitoring can significantly decrease the healthcare budget burden. TFR approach has the advantage over sustained therapy on financial cost and efficacy of its use. Disclosures Turkina: Bristol Myers Squibb: Consultancy; Pfizer: Consultancy; Novartis Pharma: Consultancy.

Introduction. Overall survival (OS) of patients in chronic phase (CP) chronic myeloid leukemia (CML) dramatically increased in the era of tyrosine kinase inhibitors (TKI). Meanwhile nearly half of patients discontinue 1-st line Imatinib due to resistance or intolerance. Half of them subsequently failure treatment with second line TKI. It seems that 20-25% of CP CML patients need 3-d line therapy (TKI-3l). There are a few reports regarding durable outcome of TKI-3l. Materials and Methods. In our retrospective study 53 patients (20 male, 33 female) with CML CP treated either by Nilotinib 400 mg BID (n=18), Dasatinib 100 mg QD (n=33) or Bosutinib 500 mg QD (n=5) as TKI-3l were included. The median age at the time of diagnosis was 46 years (23-88 years). The main reason for previous TKIs discontinuation was resistance: 48/53 (91%) had failure of one and 42/53 (79%) patients had failure of both previous TKIs treatment. Median CML duration before TKI-3l was 55 months (2-314 months). Before TKI-3l mutation analysis was performed in 35 patients: 18 mutations were revealed in 16 (46%) patients including T315I mutation in 3 cases. At the moment of 3-d line TKIs therapy initiation, all patients were in CP and 43/53 (81%) had at least complete hematologic response (CHR), 8/53 (15%) patients had major cytogenetic response (MCyR) including 1 patient with complete cytogenetic response (CCyR). Results. At the time of analysis, the median duration of TKI-3l therapy was 21 months (1-67 months). No additional patients achieved CHR, but during observational time CHR was maintained nearly in all 40/43 (93%) patients with CHR at baseline. New cases of MCyR and CCyR were observed in 15/45(33%) and 11/52(21%) of patients, respectively. Median time to MCyR and CCyR was 3.4 (3-8) and 5.2 (3-13) months, respectively. Median duration of MCyR and CCyR was 9.3 (1-43) months and 4.5 (3-6) months, respectively. Patients with resistant mutations did not obtain any cytogenetic response. TKI-3l treatment was discontinued in 21 patients. Intolerance was the reason of treatment discontinuation in 5/53(10%) cases. Progression to accelerated or blastic phases during therapy or after discontinuation occurred in 8/53 (15%) patients. Median time to progression was 14.7 months (1-46 months). There were 13 deaths in overall group of 53 patients. Two-year OS in TKI-3l was 67%. All patients with MCyR were alive and preserved CP phase. Concluson: Our results showed that 20% of patients might obtain at least CCyR and benefit with TKIs as third line. Therefore, after two TKI lines patients, who are not eligible for allogeneic transplantation and without resistant mutations should be treated with one more line of TKI therapy. Disclosures Lomaia: Novartis: Consultancy. Zaritskey:University of Heidelberg: Research Funding; Novartis: Consultancy.

Background. Thrombotic complications are the main cause of disability and mortality in Polycythemia Vera (PV) patients. Thrombosis in PV is a result of both inherited (genetic) and acquired predisposition under the external factors influence. Effective personalized prophylactic antithrombotic therapy is a key factor to save quantity and quality of life in PV patients. Objective. The objective of study was to assess the prevalence of hereditary thrombophilia genetic markers in PV patients in overall and groups with or without thrombotic complications. Materials and methods. 104 PV patients (60 females, 44 males, median age 58 years, range 31-82) were researched. Blood probes were examined by PCR for the presence of nucleotide polymorphisms in the following genes: FV (Leiden mutation), FII (prothrombin), methylenetetrahydrofolate reductase (MTHFR), fibrinogen (FI), plasminogen activator inhibitor (PAI-1), and platelet fibrinogen receptor type IIIA (GPIIIA). We studed the overall hereditary thrombophilia markers rate and the statistical significance between PV patients groups with (Thr+) or without thrombosis (Thr+). We used the next statistical methods: descriptive statistics, the significances of differences by gender and genes frequencies in the groups were evaluates with Fisher exact test, differences in age at the time of diagnosis were assessed with Mann-Whitney U test. Results. Thrombotic complications occurred in 20 (19.2%) of patients (16 arterial and 5 venous thrombotic episodes, 1 patient had both arterial and venous thrombotic episodes). Myocardial infarction was found in 7 (6.7%), cerebrovascular accident in 9 (8.7%) patients. The general PV population thrombophilia markers frequencies were: heterozygous (G/A) Leiden mutation in 4 (3,8%) patients; heterozygous mutation in prothrombin gene (G20210-A) in 4 (3,8%) patients; homozygous (T/T) mutation in MTHFR in 8 (7,7%) patients, heterozygous (C/T) mutation in 43 (41,3%) patients; homozygous (A/A) mutation in FI gene in 4 (3,8%) patients, heterozygous (G/A) mutation in FI gene in 43 (41,3%) patients; combination of mutations in FI and MTHFR was registered in 23 (22,1%) patients; homozygous (4G/4G) mutation in PAI-1 gene was revealed in 35 (33,7%) patients, heterozygous (4G/5G) mutation in 49 (47,1%) patients; mutation frequencies in GPIIIA gene were as follows: homozygous (A2/A2) in 5 (4,8%) patients, heterozygous (A1/A2) in 26 (25%) patients. The markers of hereditary thrombophilia was not identified only in one patient (1%).Characteristics and difference significances in the frequency of detection of thrombophilia genes between groups of patients with thrombosis (Thr+) and without their presence in history (Thr-) are shown in table 1. Table 1. Characteristics of PV patients with (Thr+) or without (Thr-) thrombotic complications. Thr+ (n=20) Thr- (n=84) p Age, median (range) 63 (36-73) 58 (32-82) 0.75 Gender, male/female 9/11 35/49 0.81 Factor V Leiden mutation, GA/GG 2/18 2/82 0.17 Prothrombin gene (G20210A) mutation, GA/GG 1/19 3/81 0.58 MTHFR mutation, (TT+CT)/CC 14/6 37/47 0.05 FI mutation, (AA+GA)/GG 6/14 41/43 0.14 PAI-1 mutation, (4G/4G+4G/5G)/(5G/5G) 17/3 67/17 0.76 GPIIIA mutation, (A2A2+A1A2)/A1A1 1/19 30/54 0.01 Conclusions. Various hereditary thrombophilia gene mutations were present in almost all PV patients. PV patients with and without thrombotic complications were significantly (p≤0.05) differed in frequencies of mutations in methylenetetrahydrofolate reductase gene (MTHR) and platelet fibrinogen receptor type IIIA (GPIIIA). We also observed statistical trends (p≤0.30) in differences of mutations frequencies in fibrinogen (FI) gene and Factor V Leiden mutation, for the confirmation of which the further research is required. Disclosures No relevant conflicts of interest to declare.

Background. About 70% of chronic myeloid leukemia (CML) patients achieve early molecular response (BCR-ABLIS2 10% at 3-months) that lead to 5-years overall survival close to 95%. However, CML patients remain heterogeneous group and several studies in recent years were aimed to personalize treatment based on individual patients' characteristics. Our group previously put forward a hypothesis about the prognostic value of individual BCR-ABL declinerate in the first three months of CML therapy1,2. The ratio BCR-ABL at 3 months to baseline had chosen as 0.1 as best cut-off value to predict MMR at 12 months. The aims of this study were to validate our prognostic method in larger group of patients and compare these results according to CML prognostic scores. Patients and methods. Fifty-five patients (median age, 52 years; range 19-84; 24 male and 31 female) with chronic phase CML were included in the study. Patients' distribution for Sokal risk groups were as follows: low-30 / intermediate-15 / high-10. Six patients had EUTOS high-risk. Forty-two patients started treatment with Imatinib 400 mg/day, 12 patients started with Nilotinib 600 mg/day and 1 patient started with Dasatinib 100 mg/day. Median BCR-ABL transcript levels was 41.38% at diagnosis, range 3.39-3185.36% (IS). The ratio of BCR-ABL levels at 3 months to baseline for each patient was calculated. In addition, we calculated ratio of BCR-ABL levels at 3 months to BCR-ABL levels at 1 month for 13 patients. Comparison was made of the predictive sensitivity to achieve early molecular response at 3 months (10% by IS) and according to prognostic CML scores (Sokal and EUTOS). We also assessed positive likelihood ratio (LR) value for the probability of achieving MMR between patients' stratification methods. Statistical analysis was conducted with Fisher exact test and sensitivity-specificity analyses. Results. Twenty-six out of 34 patients (76.5%) with ratio of BCR-ABL levels at 3 months to baseline below than 0.1 achieved MMR at 12 months, while only 9 of 21 patients (42.9%) with ratio more than 0.1 had optimal response (LR = 1.86 (1.05 - 3.29); p=0.003). Ratio of BCR-ABL levels at 3 months to 1 month showed much better results with the same (0.1) cut-off value - 5 out of 6 patients (83.3%) with ratio BCR-ABL at 3 months to 1 month below than 0.1, while only 1 patient (14.3%) with ratio more than 0.1 achieved optimal response (LR = 5.83 (0.92 - 37.08); p=0.05), respectively. Application of early molecular response at 3 months (10% by IS) yielded worse discrimination results: 34 of 47 (72.3%) patients with BCR-ABL level ²10% at 3 months, whereas 2 of 8 (25%) patients with BCR-ABL >10% had MMR at 1 year (LR = 1.38 (1.01 - 1.89); p=0.78), respectively. CML prognostic scores results had the following sensitivity-specificity results: for Sokal - low-risk 23 of 30 (76.7%), intermediate-risk 9 of 15 (60%) and 3 of 10 (30%) high-risk patients achieved MMR at 1 year (LR (low+intermediate)/high = 1.41 (1.00 - 1.97); p=0.03); for EUTOS-score - low-risk 34 of 49 (69.4%) and only 1 of 6 (16.7%) high-risk patients had achieved MMR at 12 months (LR = 1.30 (1.00 - 1.68); p=0.02). Furthermore, application of our ratio cut-off value among patients with BCR-ABL level ²10% at 3 months allowed us to revealed additional 6 high-risk patients have not reached MMR at 1 year of therapy (Table 1). Conclusion. Our study showed that individual rates of BCR-ABL decline from baseline to 3 months and to 1 month had better LR than CML prognostic scores (Sokal, EUTOS) or early molecular response achievement (BCR-ABL levels ²10% at 3 months) and might be useful as an optimized predictors of outcome for CML patients (MMR at 1 year of treatment). 1 Fominykh M., ShuvaevV., Martynkevich I. et al. ELN Frontiers Meeting ÇWhere science meets clinical practiceÈ 16-19 October, 2014, Berlin, Germany. Abstract book: 11. 2 Shuvaev V., Fominykh M., Martynkevich I. et al. Blood (56th ASH Annual Meeting Abstracts), 2014; 124 (21): 5529. Figure 1. The patient numbers of achieving MMR at 12 months of therapy in various stratification groups with sensitivity-specificity characteristics Figure 1. The patient numbers of achieving MMR at 12 months of therapy in various stratification groups with sensitivity-specificity characteristics Disclosures Chelysheva: Novartis Pharma: Consultancy, Honoraria; Bristol Myers Squibb: Honoraria. Turkina:Bristol Myers Squibb: Consultancy; Pfizer: Consultancy; Novartis Pharma: Consultancy.

Background. The increase of life expectancy in patients after 65 years with MM is the main aim of treatment. Lack of carrying out aggressive anti-multiple myeloma therapy increase influence of different factors on OS. Aims. To compare influence GA and other different factors on overall survival in 65 and more years old patients with MM. Methods. We retrospectively analyzed 40 patients 65 and more years (median age 71 years, range 65-86; male/female - 1:1.35). The incidences of genetic abnormalities were determined in all cases. Cytogenetic analysis was performed on bone marrow samples using standard GTG-method. Metaphase FISH analysis was performed according to the manufacturer's protocol using DNA probes: LSI 13(RB1)13q14, IGH/CCND1, IGH/FGFR3, LSI TP53 (17q13.1). Stratification of patients was carried in groups of risk according to the modified molecular classification mSMARTmod 1.0 and mSMARTmod 2.0. Patients with 2 and more chromosomal aberrations were additionally entered in high-risk group of both systems. Results. GA in multiple myeloma after 65 years old patients were detected in 22.8% (9/40). The occurrence frequency of t(11;14) was 26.0% (6/23), del(13q) - 20.8% (5/24), t(4;14) - 4.3% (n=1/23), del(17p) - 0% (n=0/11). 33/40 (82.5%) patients entered into standard risk group, 4/40 (10%) - into intermediate risk, 3/40 (7,5%) - into high-risk. Median OS (MOS) according to mSMARTmod 1.0 in standard risk group (33/40) was 78 months, in high-risk (7/40) - 54 months. Median OS according to mSMARTmod 2.0 in standard risk group (33/40) was 78 months, in intermediate-risk (4/40) - 56 months, in high-risk (3/40) - 49 months. In patients groups without renal failure (35/40) MOS was 78 vs. 46 months with renal failure (5/40). MOS isn't reached in patients with ISS I (4/27), but MOS in patients with ISS II (13/27) and ISS III (10/27) were 50 and 54 months, respectively. MOS in patients group (10/40), who have both (bortezomib and lenolidomide) anti-myeloma agents was 110 months vs. 57 months in group (30/40) only with bortezomib-based regimen of treatment. Conclusions. Many factors influence on OS in 65 and more years old patients with MM. However, patients, who had treatment with bortezomib and lenelidomide had the best results of OS. Disclosures No relevant conflicts of interest to declare.

Background. It is known, that genetic factors and the absence of minimal residual disease (MRD) are strongly affecting prognosis of chronic lymphocytic leukemia (CLL). Aim. To determine the influence of genetic abnormalities (GA) on achieving MRD-negative remissions in patients with CLL. Methods. Twenty-four adult pts (median age 57 years, range 35-67; male 14, female 10) with newly diagnosed CLL were included. The CLL was diagnosed according to the standard basic examination (complete blood count with differential, multicolor flow cytometry (MFC) of blood and bone marrow (BM), lymph node and BM immunohistochemistry (IHC), computered tomography). Cytogenetic studies were performed on blood samples using standard GTG-method. Interphase FISH analyses were performed according to the manufacturer's protocol using DNA probes: LSI 13(RB1)13q14, LSI ATM (11q22), CEP12, LSI TP53 (17p13.1) (Abbott). Immunophenotype (IFT) of CLL cells assessed with combinations: CD3/CD19, CD19/CD5, CD19/CD11c, CD19/CD20, CD19/CD22, CD19/CD23, CD19/CD25, CD19/CD38, CD19/CD43, CD19/CD81, CD19/HLA-DR, and CD19/CD5/CD23. We have used NCI revised guidelines (Hallek M, et al., 2008) for treatment initiation and assessment of response after completion of primary therapy with rituximab-based regimens (FCR or RB). All patients treated subsequently with rituximab maintenance. MRD was detected by MFC. Results. The frequency of GA in CLL was 50.0% (12/24): 15.0% (3/20) - by conventional karyotyping, 47.8% (11/23) - by FISH analyses and 9.5% (2/21) - using both methods. Stratification of patients into prognostic groups based on identified GA. Favorable prognosis (Group 1) - patients with del(13q) (n = 5); neutral prognosis (Group 2) - normal karyotype (n = 12) or trisomy of chromosome 12 (n = 3); unfavorable prognosis (Group 3) - del(11q) (n = 3) or the complex karyotype (n = 1). Statistically significant differences in the frequency of achieving MRD-negative remissions between FCR (5/11) vs. RB (5/13) were not detected (p Complete remissions (CR) were reached in 37.5% (9/24) pts, partial remissions (PR) - 62.5% (15/24). The MRD-negative remissions were reached in 10 patients: in Group 1 - 2/5 (40%; CR - 1), in Group 2 - 5/15 (33.3%, CR - 6), in Group 3 - 75.0% (3/4; CR - 2). Statistically significant differences in PFS were detected between MRD-negative vs. MRD-positive groups (p=0.03). Median PFS in MRD-negative has not been reached. Median PFS MRD-positive was 33.1 month. Conclusions. Further researches aimed at examining the relationship between the presence or absence of MRD and genetic prognostic groups, will help to understand the most important factors affecting the overall and progression-free survival. Disclosures No relevant conflicts of interest to declare.

Objectives and background. Nowadays chronic myeloproliferative neoplasms (MPN) other than chronic myelogenous leukemia undergo renaissance of interest. It results from advances in decryption of molecular mechanisms of pathogenesis and invention of target drugs. Epidemiological information is needed to assess potential effect and additional costs of new diagnostic and therapeutic techniques. The objective of our study was to review experience of MPN diagnostic and treatment in our center for past ten years. Methods. Our institution serves as primary hematological outpatient department for a half of Saint-Petersburg city with about 2 million inhabitants. We reviewed patients' charts to obtain information about incidence, symptoms, diagnostic test results, treatment options and relationship to prognostic factors. Statistical methods included descriptive statistics, nonparametric ANOVA for frequencies comparisons and Kaplan-Meyer method with log-rank test for survival comparisons in Statistica 7.0 package. Results. Since 2004 to 2013 there were 570 newly diagnosed MPN patients (pts) in our center. This group consisted of primary myelofibrosis (PMF) (203 pts; 126 female, 77 male; median age 63 years, range 16-83 years), essential thrombocythemia (ET) (201 pts; 146 female, 55 male; median age 58 years, range 23-78 years), polycythemia vera (PV) (166 pts; 96 female, 70 male; median age 57 years, range 20-85 years). The incidence rates were stable during study period: PMF incidence varied from 0.65 to 1.35 with mean of 1.01 new patient per 100 000 inhabitants per year; ET had incidence from 0.60 to 2.1 with mean of 1.00 and PV had incidence from 0.5 to 1.15 with mean of 0.83. The most prevalent symptoms of disease were: splenomegaly (65.5%), constitutional symptoms (fever, night sweats, weight loss) (31.0%), anemia (36.3%) thrombosis (24.1%) for PMF; fatigue (33.2%), headache and dizziness (25.6%), arthralgia (21.8%), erythromelalgia (15.8%) for ET; plethora (82.5%), headache and dizziness (52.4%), fatigue (31.3%) for PV. JAK2V617F was detected in 49.7% of PMF pts, 57.8% of ET pts and in 97.7% of PV pts. Thrombosis rates according WHO IPSET-thrombosis system risks` groups of ET and PV pts were: low-risk group 3.33% (3/90), intermediate-risk group 11.1% (13/117) and 39.4% (63/160) in high-risk group with highly significant (p Conclusions. Patients with MPN are presented in substantial number; therefore need much finance for novel therapy introduction. Risk stratification systems has high predictive value. Innovative drugs treatment results should be evaluated in comparison with historical control. Figure1 Overall survival in PMF patients according to DIPPS+ stratification groups. Figure1. Overall survival in PMF patients according to DIPPS+ stratification groups. Disclosures No relevant conflicts of interest to declare.

Abstract 4476 At present, the main goal of chronic myeloid leukemia (CML) therapy is to obtain complete cytogenetic response (CCyR) which is strongly associated with patient's survival. The second main factor for good prognosis after CCyR achievement is its stability. The aim of this study was to reveal factors, influencing the stability of CCyR in CML chronic phase (CML-CP) patients on Imatinib (IM) therapy in routine clinical practice. Patients and methods: In patients database of St-Petersburg and Leningrad region there are 235 CML-CP patients, who received IM for 12 months or more. Eligibility criteria for analysis were as follow: IM start dosage 400 mg/day, CCyR, which was confirmed by at least 2 consecutive cytogenetic analysis with 0% Ph+ cells in at least 20 metaphases. Patients in CCyR with IM therapy interruptions more than 3 months were censored at the date of last cytogenetic analysis. Results: 115 patients from our database were found to eligible for analysis. The median age at the diagnosis was 48 years (16-76 years). Male/female ratio was 50/65. The median time from diagnosis to IM treatment was 7 months (0.1-108 months), 55 patients begun the IM treatment in early CML-CP (≤ 6 months since diagnosis). 64, 38 and 13 patients had low, intermediate and high Sokal scores respectively. There were no differences between patients in early and late CML-CP. 56 (48,7%) patients before IM were treated with interferon. The median observation time on IM treatment was 56 months (16-88 months). Overall estimated probability of CCyR loss was 16%, rate 12.1% (14/115). In 10 patients CCyR was lost within major CyR. The estimated overall survival (all causes of death) was 78% (death rate 4.3% (5/115)), and only 1 death was CML-related. The probability of CCyR loss was not depend on previous interferon therapy and was equal in both groups -16%. The rate of CCyR loss was 15.3% (9/59) vs 8.9% (5/56) in pts with or without interferon pretreatment respectively. Sokal scores also didn't influence CCyR stability: CCyR loss rates were 10.9% (7/64), 13.2% (5/38), 15.4% (2/13) for low, intermediate and high risks, respectively (p>0.1). Probabilities of CCyR loss in different ages groups were similar: 13% (rate 8% (4/50)) vs 18% (rate 15.4% (10/65)) in patients older and younger than 50 years old, respectively (p>0.1). CCyR loss was less frequent in early CML-CP 10% (rate 3.6% (2/55)) then in late CML-CP 21% (20% (12/60)), p=0.032. For more thoroughly analysis, patients in late CML-CP were divided in subgroups related to duration of CML before IM initiation: >6 and ≤12 months, >12 and ≤60 and more than 60 months. Probabilities of CCyR loss in this groups were 22% (rate 20% (3/15)), 27% (rate 25.7% (9/35)) and 0% (rate 0% (0/10)), respectively (p Among patients, who lost CCyR, only 2/14 (14%) patients progressed to blast crisis. One of them was treated with chemotherapy followed by allo-SCT. At present, he is still alive in CCyR and complete molecular response. Another patient with blast transformation was treated by high dose IM with chemotherapy. There is no response and patient died due to progressive disease. From other patients: CCyR was re-obtained in 7 patients - in 5 patients on IM (2 pts on the same dose and 3 pts after IM dose escalation) and in 2 pts on second generation TKIs. One patient after IM dose escalation is not yet evaluable. Other 3 patients didn't respond either high dose IM or second generation TKIs, but are still alive in CML-CP. One patient lost from follow up. Conclusions: Patients in CML-CP with CCyR has very good prognosis. Very few patients progressed and dead during several years. There are two factors, which influence the probability of CCyR loss: initiation of IM in early CP and CCyR in first year of treatment are favorable to good prognosis for CCyR durability. Disclosures: No relevant conflicts of interest to declare.