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A 21-year-old woman was diagnosed with acute lymphoblastic leukemia. After the administration of intrathecal methotrexate (MTX), the patient experienced dysarthria and paralysis for one hour. Magnetic resonance imaging (MRI) performed one hour from the onset and just before symptoms disappeared revealed no abnormalities. The next day, the symptoms appeared again, and diffusion-weighed MRI revealed a high-intensity area in the left frontal lobe. The patient was diagnosed with MTX-induced encephalopathy. This case suggested that MRI performed as soon as symptoms appear might show normal findings in MTX-induced encephalopathy.

Small populations of glycosylphosphatidylinositol-anchored protein-deficient (GPI[-]) cells accounting for up to 0.01% of total granulocytes can be accurately detected by a high-sensitivity flow cytometry (FCM) assay established by the Clinical and Laboratory Standards Institute (CLSI method) and have a prognostic value in bone marrow failure (BMF); however, the significance of GPI(-) granulocytes accounting for 0.001-0.009% of granulocytes remains unclear. To clarify this issue, we examined the peripheral blood of 21 BMF patients in whom minor (around 0.01%) populations of GPI(-) granulocytes had been previously detected by a different high-resolution FCM method (OPTIMA method, which defines ≥ 0.003% GPI(-) granulocytes as an abnormal increase) using both the CLSI and OPTIMA methods simultaneously. These two methods detected an "abnormal increase" in GPI(-) granulocytes in 10 patients (48%) and 17 patients (81%), respectively. CLSI detected 0.002-0.005% (median, 0.004%) GPI(-) granulocytes in 7 patients who were deemed positive for PNH-type cells according to the OPTIMA method, which detected 0.003-0.012% (median 0.006%) GPI(-) granulocytes. The clone sizes of GPI(-) cells detected by each assay were positively correlated (r = 0.994, p < 0.001). Of the seven patients who were judged positive for PNH-type cells by OPTIMA alone, five received immunosuppressive therapy, and all of them achieved a partial or complete response. GPI(-) granulocytes detected in BMF patients by the CLSI method should thus be considered significant, even at percentages of < 0.01%.

Composite lymphoma (CL) is defined as the occurrence of two distinct types of lymphoma within the same patient. Most cases of CL involve Hodgkin and non-Hodgkin lymphomas or two distinct types of B-cell lymphomas; true CL is a composite B-cell and T-cell lymphoma, and is rare. We herein report a case involving concurrent extranodal NK/T-cell lymphoma, nasal-type and diffuse large B-cell lymphoma, which has not been previously reported. As the mechanisms and treatments of composite B-cell and T-cell lymphomas are unclear, further studies are required to improve the prognosis.

Background Tazemetostat is a selective and orally available inhibitor of enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and epigenetic regulator of cellular differentiation programs. We carried out a phase I study of tazemetostat in Japanese patients with relapsed or refractory B‐cell non‐Hodgkin‐type lymphoma (B‐NHL) to evaluate its tolerability, safety, pharmacokinetics, and preliminary antitumor activity. Methods Tazemetostat was given orally at a single dose of 800 mg on the first day and 800 mg twice daily (BID: total 1600 mg/d) on following days in a 28‐day/cycle manner. Tazemetostat dose‐limiting toxicity (DLT) was evaluated up to the end of the first treatment cycle. Archival tumor tissues were analyzed for hotspot EZH2 mutations. Results As of 15 January 2018, seven patients (four follicular lymphoma [FL] and three diffuse large B‐cell lymphoma [DLBCL]) were enrolled. The median age was 73 (range, 59‐85) years, and the median number of prior chemotherapy regimens was three (range, one to five). No DLT was observed (one patient was not evaluable due to early disease progression). The common treatment‐related adverse events (AEs) were thrombocytopenia and dysgeusia (three patients each; 42.9%). No treatment‐related serious AEs were observed. The objective response rate was 57% (4/7 patients), including responses in three of four patients with FL and one of three patients with DLBCL. An EZH2 mutation was detected in one patient with FL responding to treatment. Conclusions Tazemetostat at 800 mg BID showed an acceptable safety profile and promising antitumor activity in Japanese patients with relapsed or refractory B‐NHL., Tazemetostat is a selective and orally available inhibitor of enhancer of zeste homolog 2 (EZH2), a histone methyltransferase acting as an epigenetic regulator of cellular differentiation programs. Tazemetostat at 800 mg BID demonstrated an acceptable safety profile and promising antitumor activity in Japanese patients with relapsed or refractory B‐cell non‐Hodgkin‐type lymphoma.

Cytoreductive therapy is used in high-risk essential thrombocythemia (ET) to reduce risk of thrombohemorrhagic complications. Anagrelide is an orally active, quinazolone-derived platelet-lowering agent approved for first-line treatment of high-risk ET in Japan. Long-term safety and efficacy data were collected from 53 Japanese high-risk ET patients (Study 308); 41 patients who completed Study 308 entered this phase 3b, open-label extension (Study 309; NCT01467661). Reductions in mean platelet counts occurred throughout the study, from 1021.6 × 109/L (at Study 308 baseline) to 675.4 × 109/L at final assessment. At month 48 (since Study 308 enrollment), mean platelet count was 444.5 × 109/L in the 10 patients who completed 4 years of therapy. Overall, platelet counts decreased from 1088.3 × 109/L at Study 308 baseline (n = 33) to 473.5 × 109/L at final assessment (n = 31). Long-term platelet count reductions were maintained without marked changes in mean anagrelide dose. Anagrelide was generally well tolerated, with anemia (54.7%) and headache (49.1%) as the most frequent adverse events. These findings indicate that anagrelide effectively reduces platelet counts in high-risk Japanese ET patients, with titration resulting in a well-tolerated, effective and sustainable dose. In conclusion, these results support anagrelide administration to high-risk Japanese ET patients using individualized dosing strategies defined in instructions previously approved in Europe and the USA.

Overexpression of programmed death-1 (PD-1) ligands contributes to an immunosuppressive microenvironment. Nivolumab is a PD-1-blocking antibody that inhibits the PD-1 pathway and showed good efficacy in several types of malignancy. This phase II study examined the efficacy and safety of nivolumab in 17 Japanese patients with refractory/relapsed classical Hodgkin lymphoma previously treated with brentuximab vedotin. Sixteen patients were included in efficacy analyses and 17 in safety analyses. The primary endpoint was the centrally assessed objective response rate (ORR). The study was commenced in March 2015. We report data obtained at a cutoff of 16 March 2016, at which time 11 patients were still receiving nivolumab. The median (range) duration of treatment and follow-up were 7.0 (1.4-10.6) months and 9.8 (6.0-11.1) months, respectively. All 17 patients had previously received brentuximab vedotin. The ORR was 81.3% (95% confidence interval [CI]: 54.4-96.0%; 13/16 patients), with complete remission and partial remission in 4 and 9 patients, respectively. The overall survival (OS) and progression-free survival (PFS) rates at 6 months were 100 and 60.0% (95% CI: 31.8-79.7%), respectively; the median OS and PFS were not reached. The most common adverse events (AE) were pyrexia (41.2%), pruritus (35.3%), rash (35.3%) and hypothyroidism (29.4%). Four patients (23.5%) experienced grade 3 or 4 AE, but most AE were of grade 1 or 2. In conclusion, nivolumab is a potentially effective and tolerable treatment option for Japanese patients with relapsed/refractory classical Hodgkin lymphoma previously treated with brentuximab vedotin.

We evaluated the safety, efficacy, pharmacokinetics, pharmacodynamics and predictive biomarkers of tirabrutinib, a second-generation, enhanced-selectivity Bruton's tyrosine kinase inhibitor in Japanese patients with relapsed/refractory B-cell non-Hodgkin lymphoma (B-cell NHL) and chronic lymphocytic leukemia (CLL). This was an open-label, multicenter, phase I study. Seventeen patients (male N = 8) with a median age of 70 years were enrolled in 4 dose cohorts (160 mg once daily [N = 3], 320 mg once daily [N = 3], 480 mg once daily [N = 4] and 300 mg twice daily [N = 7]); 4 patients had continued tirabrutinib administration as of 4 January 2018. The maximum tolerated dose was not reached. Pneumonitis (N = 1) was the dose-limiting toxicity for 300 mg twice daily. Common adverse events (AEs) were rash (35.3%) and vomiting (29.4%). Eight patients (47.1%) developed grade ≥3 AEs: neutropenia (23.5%), anemia (11.8%) and leukopenia (11.8%) were frequent. The overall response rate (≥PR) was 76.5% (13/17 patients), including 4 DLBCL patients with no CD79A/B or MYD88 mutations, and 1 CLL patient with a TP53 mutation, providing promising data for future developments. Of 16 patients with measurable lesions during the screening period, 12 showed ≥50% reductions in tumor diameter. In many patients, the tumor size decreased soon after beginning treatment. The maximum serum concentration for tirabrutinib was 611, 1220, 1280 and 886 ng/mL on Day 1 and 484, 971 1940, and 961 ng/mL on Day 28 for Cohorts 1-4, respectively. Tirabrutinib pharmacokinetics were linear, with little accumulation following multiple doses. Tirabrutinib was well tolerated and showed promising efficacy for B-cell NHL/CLL.

Background This study aimed to develop a simple and inexpensive method using the complete blood count (CBC) and differentials to screen for chronic myeloid leukemia (CML). Methods The receiver operating characteristic (ROC) curves of each CBC parameter, differential and the neutrophil alkaline phosphatase (NAP) score using CML and non-CML cases were generated to determine effective cut-off values. They were applied to the review of randomly-selected 45,608 samples for validation. Results The leukocyte count showed the highest area under the ROC curve (AUC) value (0.909) among the CBC parameters. In the absolute counts of differentials, the AUC was the highest in basophils (0.982), followed by immature granulocytes (IGs) (0.975), which had cut-off values of 0.43 × 109/L and 0.46 × 109/L, respectively. The AUC of the NAP score was 0.963 at a cut-off value 122. In the validation, the absolute basophil counts were elevated in 280 samples from 96 cases, including 22 CML cases. In contrast, the absolute IG counts were elevated in 1310 samples from 516 cases, including only 17 CML cases. Three newly-diagnosed CML cases whose data were analyzed sequentially at the CML onset consistently met the basophil criteria before the IG criteria. Conclusions The absolute basophil count is effective for screening for CML.

The EuroQol 5-dimension scale (EQ-5D) is one of the most frequently used preference-based quality of life (QOL) measures for health technology assessment. The 3-level version of the EQ-5D comprises a descriptive system (the EQ-5D-3L) and a visual analog scale (EQ-VAS). It remains unclear whether this five-item scale correlates with the QOL of patients with oral cancer during the perioperative period. We sought to clarify this point in the present study.Participants were 84 patients with oral malignancies who underwent radical treatment and completed the EQ-5D-3L and Functional Assessment of Cancer Therapy-Head and Neck (FACT-HN) at regular intervals over 3 months after treatment. We analyzed the correlations between the EQ-5D-3L, EQ-VAS, and FACT-HN, and conducted multiple regression analyses to examine how the FACT-HN subscales relate to the EQ-5D-3L and EQ-VAS. We also investigated whether the EQ-5D-3L shows ceiling effects.The EQ-5D-3L and EQ-VAS were strongly correlated with the FACT-HN (rOur results indicate that actual physical performance might be most important for cost-utility analysis, whereas the assessment of familial feelings or friendship seems less important. However, the EQ-5D-3L appears to generally correlate with the FACT-HN of patients with oral cancer during the perioperative period. Therefore, it is reasonable to assess the cost performance of oral cancer treatment using the EQ-5D-3L in Japan.

Cytarabine arabinoside (Ara-C) is the most important agent for treating acute myeloid leukemia (AML). Here, we genotyped 11 single nucleotide polymorphisms (SNPs) of seven Ara-C metabolism-related genes in 39 AML patients who had received high-dose Ara-C as a single-agent treatment. Univariate analysis identified three SNPs that were significantly associated with shorter time-to-relapse (TTR): CTPS rs12144160 GG compared to AA/AG, DCTD rs9990999 AG/GG compared to AA, and SLC29A1 rs693955 CC compared to AA/AC. Multivariate analysis of TTR revealed the SLC29A1 rs693955 CC genotype and first induction failure to be significantly associated with a shorter TTR. The DCTD rs9990999 AG/GG and SLC29A1 rs693955 CC genotypes were also significantly associated with shorter duration of neutropenia. The results of our study suggest that SNP analysis can be an important tool in improving drug responsiveness and enabling a better understanding of this condition and the development of tailor-made treatments for AML patients who benefit from consolidated high-dose Ara-C therapy.

Minor populations of glycosylphosphatidylinositol-anchored protein-deficient (GPI[−]) cells in the peripheral blood may have a prognostic value in bone marrow failure (BMF). Our objective is to establish the optimal flow cytometry (FCM) assay that can discriminate GPI(−) populations specific to BMF from those of healthy individuals. To identify a cut-off that discriminates GPI(−) rare cells from GPI(+) cells, we determined a position of the borderline that separates the GPI(−) from GPI(+) cells on a scattergram by testing more than 30 healthy individuals, such that no GPI(−) dot fell into the upper left quadrant where fluorescein-labeled aerolysin (FLAER)−CD11b+ granulocytes and CD55−CD59− glycophorin A+ erythrocytes were positioned. This method allowed us to define ≥ 0.003% CD11b+FLAER− granulocytes and ≥ 0.005% glycophorin A+CD55−CD59− erythrocytes to be specific to BMF patients. Longitudinal cross-validation studies showed minimal (

The estimation of clinical prognosis for diffuse large B-cell lymphoma (DLBCL) with a quick, cost-efficient method is necessary because of the clinical heterogeneity of this disease, which leads to death, relapsed or refractory disease in approximately 40% of patients. We analyzed 320 cases diagnosed from 2007 to 2013 treated with R-CHOP therapy at Tokai University Hospital and associated institutions. DLBCL was classified according to the cell-of-origin using the Hans algorithm [germinal center B-cell-like (GCB) vs non-GCB subtypes], and into 6 subgroups derived from combinations of CD10, BCL6 and MUM1 markers. The percentage of GCB and non-GCB (NGCB) subtypes was 35% and 65%, respectively. GCB-DLBCL was characterized by lower BCL2 immunohistochemical expression, extranodal sites

SummaryIntroduction The management of pregnant women with acute leukemia is usually challenging. We collected data concerning pregnant women with acute leukemia in the Kanagawa area in Japan. Methods A questionnaire was sent to 24 institutions in the Kanagawa area. Results Data were obtained for 11 patients, median age of 31 years (range, 20–36). Eight patients had acute myeloid leukemia and three had acute lymphoblastic leukemia. Six patients were diagnosed in the first trimester of pregnancy, one in the second trimester, and four in the third trimester. Five of six patients diagnosed in the first trimester had abortions before chemotherapy, and one had an elective abortion after receiving chemotherapy. All patients diagnosed in the second or third trimester delivered live infants. Of the six patients diagnosed in the first trimester, two died of recurrent leukemia, and four remained in remission. Of the five patients diagnosed in the second or third trimester, four achieved complete remission and remained in remission. One patient died of sepsis 4 days after cesarean section. Conclusions Careful surveillance and monitoring of the fetus and close co-operation among hematologists, gynecologists, and pediatricians are essential to successfully treat pregnant women with acute leukemia.

Dasatinib is a BCR-ABL kinase inhibitor with improved potency compared with imatinib, for which efficacy and safety in imatinib-resistant and imatinib-intolerant patients with chronic myelogenous leukemia (CML) have been established. Here, an open-label phase II study evaluated the efficacy and safety of dasatinib in 50 Japanese patients with imatinib-resistant or imatinib-intolerant CML during the chronic phase (CML-CP). Dasatinib was effective in imatinib-resistant and imatinib-intolerant patients. After 12 months of dasatinib therapy, 35 patients (70%) had achieved a major molecular response (MMR) and 16 patients (32%) had achieved a complete molecular response (CMR). Among the imatinib-resistant CML-CP cohort, 21 and 8 patients had achieved an MMR and a CMR after 12 months of dasatinib therapy, respectively. Among the imatinib-intolerant CML-CP cohort, 14 and 8 patients had achieved an MMR and a CMR after 12 months of dasatinib therapy, respectively. After 18 months of dasatinib therapy, 38 out of 50 patients (76.0%) had achieved an MMR and 19 patients (38.0%) had achieved a CMR. A lower level of BCR-ABL transcript at 1 or 3 months after the initiation of dasatinib treatment was more strongly correlated with the BCR-ABL transcript level at 12 and 18 months (p ＜ 0.001) than a higher level of BCR-ABL. The T315I mutation was identified in two patients receiving dasatinib therapy. Dasatinib was generally well tolerated, with only 3 patients (5%) having treatment discontinuation as a result of adverse hematologic events (thrombocytopenia, anemia, neutropenia) and/or non-hematologic events at a 12-month follow-up evaluation. Dasatinib was a safe and effective treatment for Japanese patients with imatinib-resistant or imatinib-intolerant CML. In addition, the molecular response at 1 or 3 months predicted a response to dasatinib at 12 or 18 months.

Lymphocytosis in response to dasatinib for chronic myelogenous leukemia (CML) may be associated with favorable response. However, it occurs at varying times and in a limited subset of patients. To identify early clinical markers for favorable responses applicable to all patients with or without lymphocytosis, we prospectively analyzed lymphocyte profiles of 50 Japanese CML patients treated with dasatinib after intolerance/resistance to imatinib. Although absolute lymphocyte counts did not differ significantly until 3 months between patients with complete molecular response (CMR) at 12 months and those without it, relative increases in lymphocyte compared with baselines differed significantly from 1 month. Patients with relative lymphocyte counts150 % at 1 month or200 % at 3 months had higher CMR rates at 12 months than others (57.9 vs. 23.3 %, P = 0.015, and 76.5 vs. 16.1 %, P0.0001, respectively). A relative increase in lymphocyte subset of CD57(+)CD14(-), CD8(+)T, or NK cells200 % at 1 month was also significantly associated with a higher CMR rate. There were significant negative correlations between relative lymphocyte increases and BCR/ABL transcript levels. CD57(+)CD14(-) cells were a highly specific focus of proliferation. Relative increases in lymphocyte count and its subsets from 1 month are reliable early markers of favorable responses to dasatinib.

The tolerability, efficacy, safety and pharmacokinetic profile of a human anti-CD20 monoclonal antibody, ofatumumab, was evaluated in this phase I/II study in patients with relapsed or refractory B-cell chronic lymphocytic leukemia (B-CLL). This study consisted of two parts. Tolerability was assessed in phase I (Part A), while the overall response rate (ORR) was assessed in phase II (comprising Parts A and B). Three patients were enrolled in Part A, and another seven patients were enrolled in Part B. Ofatumumab 300 mg was given at the first infusion, followed by seven weekly and four monthly infusions of 2000 mg. No patients experienced dose-limiting toxicity, and tolerability was confirmed. The ORR was 70 %. The most commonly reported adverse events (AEs) were leukopenia, neutropenia, and lymphopenia. No patients discontinued the study due to AEs. Plasma concentrations of ofatumumab prior to the next weekly dose increased steadily over the 8 weeks and did not reach steady state; with monthly dosing, pre-dose ofatumumab concentrations decreased. Inter-patient variability of pharmacokinetic parameters was larger after the first dose than after the later dose. In conclusion, this phase I/II study suggests that ofatumumab provides favorable safety and efficacy in Japanese/Korean patients with relapsed or refractory B-CLL.

A recent study reported that treatment-free remission (TFR) of chronic myeloid leukemia (CML) after dasatinib (Das) treatment was significantly associated with natural killer (NK) cell proliferation in the peripheral blood. However, biomarkers to predict lymphocytosis or successful TFR are not well characterized. In order to clarify individual differences in NK cell responses among patients treated with Das, we retrospectively analyzed the association between polymorphisms in the natural killer group 2D receptor [NKG2D; also known as killer cell lectin like receptor K1 (KLRK1)] gene and clinical outcomes in 31 patients treated with Das as first-line treatment for CML. Patients with the NKG2D HNK1/HNK1 (high-cytotoxic activity-related allele on NKG2D hb-1) haplotype achieved MR4.5 more quickly than those with other haplotypes [hazard ratio (HR) 4.39; 95% confidence interval (CI) 2.75–118.6; P = 0.004]. In addition, NK cells with the NKG2D HNK1 allele exhibited enhanced phosphorylation of vav guanine nucleotide exchange factor 1 (VAV1) at Tyr174. These data suggest that NKG2D gene polymorphisms may represent candidate biomarkers for the prediction of TFR following Das treatment.

We present a case of a 46-year-old Japanese woman with an eosinophilic ulcer of the oral mucosa (EUOM), located in the buccal mucosa, who was found by various examinations to be a human T-cell leukemia virus type I (HTLV-1) carrier with peripheral eosinophilia. Her peripheral eosinophilia and EUOM promptly improved in response to oral corticosteroid therapy. EUOM has been described to be possibly associated with trauma, but its etiology has not been fully elucidated to date. In the present case, the presence of peripheral eosinophilia in addition to the EUOM indicated possible influence of certain immune system abnormalities associated with HTLV-1 infection.

Patients with head and neck squamous cell carcinoma are at an increased risk of developing second malignancies. Most commonly, these second primary malignancies are squamous cell carcinoma of the head and neck region, but also noted are esophageal cancer or lung cancer. Hematologic malignancies are uncommon second malignancies. Diagnosis can be challenging, particularly when a patient suffers metastases of squamous cell carcinoma to the cervical lymph nodes in addition to synchronous or metachronous malignant lymphoma that originates in the cervical lymph nodes. This article describes a case of primary follicular lymphoma in the cervical region that was discovered during a postoperative follow-up after partial glossectomy and neck dissection for tongue cancer.

Real-time quantitative polymerase chain reaction (RQ-PCR) has been widely used for molecular monitoring for patients with chronic myeloid leukemia (CML). Currently, RQ-PCR is not based on the concept of international scale (IS) in Japan; mainly because none of the domestic laboratories have obtained their own conversion factor (CF) which makes it possible to convert locally scaled BCR-ABL (BCR-ABL (L)) value to the IS (BCR-ABL (IS)). To join the global trend of molecular assessment of BCR-ABL in CML patients, we have tried to obtain a CF in Japan.Samples from 55 patients were exchanged between the Japanese laboratory and the reference laboratory in Adelaide, and BCR-ABL and internal control gene transcripts of the samples were measured using RQ-PCR. The patient bias conversion method was used to determine the CF for the IS using the Bland and Altman method.The local CF in the Japanese laboratory was determined to be 0.87. Based on this CF, 0.1% BCR-ABL (IS), defined as major molecular response, becomes equivalent to 731 copy/μg RNA BCR-ABL (L).This study is the first to introduce a laboratory-specific CF for harmonizing RQ-PCR methodology for detecting BCR-ABL transcripts to Japan, which may open new windows for molecular assessment of CML patients in Japan.

The efficacy and safety of romiplostim, a thrombopoietin-mimetic peptibody, were evaluated in a double-blind, placebo-controlled, randomized trial of Japanese patients with chronic immune thrombocytopenia (ITP). Thirty-four ITP patients received romiplostim (n = 22) or placebo (n = 12) for 12 weeks, with a starting romiplostim dose of 3 μg/kg weekly. The primary end point was the number of weeks with platelet response, defined as a platelet count ≥50 × 10(9)/L (not including the 4 weeks after rescue medication administration). Patients received a median of 4 (range 1-19) prior ITP therapies including splenectomy in 44%. On study, 68% also received concomitant ITP therapy. Weekly responses occurred for a median of 11 weeks with romiplostim as compared to 0 weeks with placebo (p 0.0001). Most romiplostim-treated patients (95%) achieved platelet responses; two showed extended responses after the treatment period. The use of rescue medication was required in 9% of romiplostim-treated patients as compared with 17% of placebo-treated patients. Both treatment groups had similar incidences of adverse events (91% romiplostim, 92% placebo). Adverse events that occurred more frequently (10%) in romiplostim-treated patients included nasopharyngitis, headache, peripheral edema, back pain, and extremity pain. In conclusion, romiplostim significantly increased and maintained platelet counts and was well tolerated in Japanese patients with ITP.

Introduction We previously reported an interim analysis of the DADI (dasatinib discontinuation) trial. The results showed that 48% of patients with chronic myeloid leukemia in the chronic phase who maintained a deep molecular response (DMR) for ≥ 1 year could discontinue second- or subsequent-line dasatinib treatment safely at a median follow-up of 20 months. However, the results from longer follow-up periods would be much more useful from a clinical perspective. Patients and Methods The DADI trial was a prospective, multicenter trial conducted in Japan. After confirming a stable DMR for ≥ 1 year, dasatinib treatment subsequent to imatinib or nilotinib was discontinued. After discontinuation, the loss of DMR (even of 1 point) was defined as stringent molecular relapse, thereby triggering therapy resumption. The predictive factors of treatment-free remission (TFR) were analyzed. Results The median follow-up period was 44.0 months (interquartile range, 40.5-48.0 months). The estimated overall TFR rate at 36 months was 44.4% (95% confidence interval, 32.0%-56.2%). Only 2 patients developed a molecular relapse after the 1-year cutoff point. The presence of imatinib resistance was a significant risk factor for molecular relapse. Moreover, high natural killer cell and low γδ+ T-cell and CD4+ regulatory T-cell (CD25+CD127low) counts before discontinuation correlated significantly with successful therapy discontinuation. Conclusion These findings suggest that discontinuation of second- or subsequent-line dasatinib after a sustained DMR of ≥ 1 year is feasible, especially for patients with no history of imatinib resistance. In addition, the natural killer cell count was associated with the TFR.

Background: Idiopathic thrombocytopenic purpura (ITP) is associated with the cytokine response and dysregulation of the cytokine network. Gene polymorphisms of proinflammatory cytokines are associated with several diseases including ITP. Recently, the successful eradication of Helicobacter pylori has been reported to improve the platelet counts in some patients with ITP. The aim of this study was to elucidate the relationship between cytokine gene polymorphisms and platelet recovery in ITP patients after the eradication of H. pylori. Materials and Methods: Gastric H. pylori infection was confirmed using a culture method or specific IgG antibodies against H. pylori in the serum. Thirty-six adult H. pylori-positive ITP patients received antibiotic therapy for H. pylori. The response to treatment was defined as complete response (CR) if the platelet count was above 150 × 103/µl and partial response (PR) if the platelet count increased by more than 50 × 103/µl above the pretreatment count. Genomic DNA was extracted from peripheral blood and polymorphisms in IL-1B (–31, –511), IL-1RN (long or short), TNFA (–308) and TNFB (+252) were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: Of the 36 ITP patients, twenty patients (responders) exhibited a platelet response after successful H. pylori eradication therapy, but the other patients (nonresponders) did not. There were no statistical differences in the frequencies of polymorphisms in IL-1B, IL-1RN and TNFA genes between responders and nonresponders. In contrast, the frequency of responders in ITP patients with the TNFB G/G or G/A genotype was significantly higher (69.6%) than that with the TNFB A/A genotype (30.8%). Conclusion: The TNFB (+252) G/G or G/A genotype may therefore be a good predictor of platelet recovery in ITP patients after the eradication of H. pylori.

Primary immune thrombocytopenia (ITP) is an autoimmune disease mediated by the production of autoantibody against platelets. Rituximab, an anti-CD20 antibody, is reported to be useful for treatment of ITP. In Japan, however, robust evidence on this treatment has not been accumulated. Hence, we conducted this open-label phase III clinical trial to confirm the efficacy and safety of rituximab, administered at 375 mg/m² once per week at weekly intervals for 4 consecutive weeks in Japanese patients with chronic ITP, who had relapsed and were refractory to conventional therapy. The primary endpoint was defined as the percentage of patients with a platelet count above 50 × 10⁹/L at week 24 after the first dose of rituximab, which was 30.8% of 26 patients (95% confidence interval 14.3-51.8%). Although the lower confidence limit of primary endpoint failed to meet the pre-specified threshold of 20%, the clinical efficacy of rituximab is substantial in consideration of the 2% response rate in the placebo arm in other clinical studies in patients with chronic ITP. We conclude that rituximab is clinically useful and safe in the treatment of Japanese patients with chronic ITP, achieving the goal of maintaining platelet count and reducing risk of bleeding while minimizing treatment-related toxicity.

To determine the safety and the appropriate dose of intravenous l-ascorbic acid (AA) in conjunction with chemotherapy for patients with relapsed lymphoma.Patients with relapsed CD20-positive B-cell non-Hodgkin's lymphoma, who were going to receive the CHASER regimen as salvage therapy, were enrolled and treated with escalating doses of AA administered by drip infusion after the 2nd course of the CHASER regimen. The target plasma concentration immediately after AA administration was15 mM (264 mg/dl).A serum AA concentration of15 mM was achieved in 3 sequentially registered patients, all of whom had received a 75 g whole body dose. No obvious adverse drug reaction was observed in the patients. The trial was therefore successfully completed.Intravenous AA at a whole body dose of 75 g appears to be safe and sufficient to achieve an effective serum concentration. A phase II trial to evaluate the efficacy of intravenous AA in relapsed/refractory lymphoma patients will now be initiated.

Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired stem cell disorder with the expansion of PIGA mutant clone(s), which is deficient in GPI-anchored proteins including CD55 and CD59. The lack of CD55 and CD59 renders PNH-type red blood cells (RBC) susceptible to complement attacks, resulting in intravascular hemolysis. Classic PNH manifests 3 major symptoms: anemia, bone marrow failure, and thrombosis. Small populations of PNH-type cells ( Methods: Patients diagnosed with PNH, AA, MDS or indistinguishable BMF were prospectively recruited to the study since 2011 in Japan. A high-resolution FCM assay was established to precisely detect a small population of PNH-type granulocytes (with FLAER) and RBCs (with anti-CD55 and CD59 antibodies) ≤ 0.01% of the total granulocyte or RBC population based on the Kanazawa method (Blood 2006 107:1308-1314). Six university laboratories across Japan were designated as regional analyzing centers and measured the percentages of PNH-type cells in the study population, as well as collected clinical and laboratory data. Periodic blind cross validation tests using a positive control sample containing 0.01% PNH-type cells and a negative control sample were performed to minimize inter-laboratory variations. Results: As of July 2016, 2,849 patients were enrolled in the study and 2,734 patients were analyzed. Nine hundred twelve patients (33.4%) were positive for PNH-type cells (≥ 0.005% PNH-type erythrocytes and/or ≥ 0.003% PNH-type granulocytes) and 238 (8.7%) patients had more than 1% of PNH-type cells. PNH-type cells were positive in 90/90 PNH (100%), 512/982 AA (52.1%), 132/822 MDS (16.1%), and 141/512 indistinguishable BMF (27.5%) patients. Among the MDS patients, PNH-type cells were positive in approximately 20% of patients with RCUD, RCMD, MDS-U, or 5q- syndrome, but not in any patients with RARS, RAEB-1, and RAEB-2 (Fig. 1). The serum LDH level increased in proportion to the PNH clone size of RBCs, and 63.3% of the patients possessing ≥1.0% RBCs showed LDH levels more than 1.5 times the upper limit of normal. Of 171 patients who completed submission of 3-year follow-up data, BMF patients with PNH-type cells showed a better response rate [CR+PR, 99/107 (92.5%)] to IST compared to those without PNH-type cells [44/64 (68.8%)] (P Conclusions: These interim analyses of the OPTIMA study demonstrate that our high-resolution FCM is reliable in detecting small populations of PNH-type cells and produces consistent results among different laboratories. The presence of PNH-type cells exclusively in patients with AA and low-risk MDS suggests a link between benign pathophysiology of BMF and an increase in the number of PNH-type cells. The better response of PNH-type cell-positive BMF to IST compared to BMF without PNH-type cells was consistent with previous reports. Our data, for the first time, prospectively confirms the significance of small populations of PNH cells in BMF patients in Japan and warrants further worldwide, prospective studies on non-Japanese patients with BMF. Disclosures Ueda: Alexion Pharmaceuticals: Honoraria, Research Funding. Nishimura:Alexion Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Hosokawa:Aplastic Anemia and MDS International Foundation: Research Funding. Yonemura:Alexion Pharmaceuticals: Research Funding. Obara:Alexion Pharmaceuticals: Honoraria, Research Funding. Shichishima:Alexion Pharmaceuticals, Inc. Japan: Honoraria. Ninomiya:Alexion Pharmaceuticals: Honoraria. Kawaguchi:Alexion Pharmaceuticals: Honoraria. Kanakura:Fujimotoseiyaku: Research Funding; Toyama Chemical: Research Funding; Bristol - Myers: Research Funding; Nippon Shinyaku: Research Funding; Astellas: Research Funding; Eisai: Research Funding; Pfizer: Research Funding; Chugai Pharmaceutical: Research Funding; Shionogi: Research Funding; Kyowa Hakko Kirin: Research Funding; Alexion Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Nakao:Alexion Pharmaceuticals: Honoraria, Research Funding.

Dasatinib (DA) is a tyrosine kinase inhibitor (TKI), and is approved for the treatment of naïve and relapsed/refractory Philadelphia chromosome positive leukemia. DA is a potent and multi-target TKI, and a part of patients treated with DA are reported to exhibit lymphocytosis and that is caused by a proliferation of NK cells or CD8 T cells. Nowadays, a lot of reports about the stop TKI trials suggested that treatment free remission of the CML after TKI discontinuation was significantly associated with NK cell proliferation in peripheral blood of the patients. So far, little is known about the individual differences in NK cell response among patients treated with Dasatinib. NKG2D is an activating receptor expressed on NK cells. Recently, functional SNP were identified between LNK1 and HNK1 haplotypes of the NKG2D gene. We analyzed the association between patient's NKG2D polymorphism and achievement of the deep molecular response by Dasatinib. We retrospectively investigated thirty-one patients who were treated with Dasatinib for the first-line treatment of CML at Tokai university school of medicine between 2011 and 2015. Patients with HNK1 haplotype tended to achieve MR4.5 more frequently (not significant), and these patients accomplished MR4.5significantly faster than others. Next, we harvested NK cells from healthy volunteers, and investigated NK cell responses by Dasatinib in vitro. There were differences in the degree of NK cell proliferation capacity among subjects after DA treatment in vitro. We found that NK cells with NKG2D LNK1/LNK1 haplotype exhibited significantly lower proliferation capacity than others in the population. NK cells of higher proliferation capacity exhibited Vav-1 Tyr174 phosphorylation, but they didn't show any differences in cytotoxicity capacity. In this study, our data suggest that DA may stimulate NK cells with NKG2D HNK1 haplotype more strongly than LNK1 haplotype, and therefore patients with HNK1 haplotype can achieve deep molecular response faster than others. So, personalized medicine according to their NKG2D haplotype may be useful to the treatment of CML, especially when they are considered to discontinue DA in stop TKI trials. Disclosures No relevant conflicts of interest to declare.

e19018Background: The programmed death-1 (PD-1) immune checkpoint pathway regulates T-cell-mediated antitumor immune responses in various tumors. Nivolumab (Nivo) (Ono Pharmaceutical, Bristol-Myers...

We conducted a retrospective study to evaluate outcomes and prognostic factors of newly diagnosed patients with t(8;21) acute myeloid leukemia (AML). There were 70 patients (43 men and 27 women) with a median age of 48 years old (range, 17∼76 years old). Sixty-five patients achieved complete remission (CR) after induction chemotherapy. Fifty-seven patients received consolidation chemotherapy based on the policy of not performing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the time of first CR. Twenty-seven of the 57 patients relapsed (relapse rate, 47%). The median time from the achievement of the first CR to relapse was 307 days (96∼1,256 days). A white blood cell count of more than 25,400/μl at diagnosis was associated with a higher relapse rate than a white blood cell count of less than or equal to 25,400/μl (75% vs. 43%, P=0.04). Nineteen of the 25 relapsed patients who received re-induction therapy experienced a second CR (second CR rate, 76%). Twenty-six patients (5 with first CR, 12 with second CR, and 9 without remission) received allo-HSCT. The five-year overall survival and disease-free survival rates were 61% and 45%, respectively. Patients with t(8;21) AML had a high CR rate, but about half of them relapsed. However, this report could not show prognostic factors for the identification of patients who should receive allo-HSCT at the time of their first CR.

Long-term use of the thrombopoietin mimetic romiplostim was examined in Japanese patients with chronic immune thrombocytopenic purpura (ITP) in this open-label extension. The starting dose of romiplostim was the previous trial dose or 3 μg/kg/week, which was titrated up to 10 μg/kg/week to maintain platelet counts between 50 and 200 × 10(9)/L. As of April 2010, 44 patients had enrolled; 71 % women, median age 55.5 years, with five patients discontinuing romiplostim due to patient request (2), administrative decision (2), or not achieving study-defined platelet response (1). Median treatment duration was 100 weeks; median average weekly dose was 3.8 μg/kg. Twenty-eight patients (64 %) self-injected romiplostim. The most frequent adverse events were nasopharyngitis and headache. Nine patients (20 %) had a total of 14 serious adverse events (0.31/100 patient-weeks); of these, only oral hemorrhage was considered treatment related. Fifty hemorrhagic adverse events were reported in 20 patients (46 %) (1.12/100 patient-weeks). Ninety-six percent of patients had a platelet response (doubling of baseline platelet count and platelet count ≥ 50 × 10(9)/L). Of the 25 patients receiving concurrent ITP therapy at baseline, all reduced or discontinued the therapy. Eight patients (18 %) received rescue medications. Administration of up to 3.5 years of romiplostim increased platelet counts and was well tolerated in Japanese patients with chronic ITP.

This phase II, multicenter, open-label, sequential-cohort, dose-escalation study was designed to evaluate the safety and efficacy of romiplostim, a novel peptibody that increases platelet production, in Japanese patients with chronic immune thrombocytopenic purpura (ITP). Sequential cohorts of four patients each received romiplostim (1, 3, or 6 microg/kg) subcutaneously on days 1 and 8 of the dose-escalation phase. Patients who achieved platelet responses (doubling of baseline platelet counts toor =50 x 10(9)/L) continued romiplostim weekly during the treatment-continuation phase. Romiplostim produced dose-dependent increases in mean and peak platelet counts. Five patients received romiplostim during the treatment-continuation phase, with platelet countsor =50 x 10(9)/L maintained in approximately half of the weekly assessments. Romiplostim was well tolerated. No severe, serious, or life-threatening adverse events were reported. No binding antibodies to romiplostim or thrombopoietin were detected. Romiplostim is safe and well tolerated in Japanese patients with chronic ITP and is effective in producing platelet count increases, consistent with the results from studies in non-Japanese patients. On the basis of these findings, a starting dose of 3 microg/kg was recommended for phase III evaluation of romiplostim in Japanese patients with chronic ITP.

Hematopoietic stem cells (HSCs) consist of heterogenous subpopulations, one of which is CD34(-) HSCs. Recent development of successful engraftment by intra-bone marrow transplantation revealed severe combined immunodeficiency (scid) mouse-repopulating cell (SRC) activity in human CD34(-) cord blood (CB) cells. On the other hand, CD34(-) cells from bone marrow (BM) cells remain relatively undefined. Here, we investigated pre-SRC populations in human BM CD34(-) cells and the effect of the niche-related factor, angiopoietin-1, on them.Two populations in BM CD34(-) cells (namely M cells and S cells) were purified by flow cytometry. Then, they were cocultured with six growth factors on the hematopoietic-supportive mouse BM stromal cell line, HESS-5 or AHESS-5 that were engineered to produce human angiopoietin-1, because we detected Tie2 expression on M cells and S cells. Cultured cells were assessed for their in vitro and in vivo hematopietic activities.After 7 days in coculture, AHESS-5 was stronger more effective than HESS-5 in converting M and S cells to CD34(+) cells (M cells: 67.4% vs 17.5%, n =6, p0.001) (S cells: 42.3% vs 2.3%, n = 6, p0.001). Furthermore, both M and S cells were able to engraft in immunodeficient mice after they were cocultured on AHESS-5.Results suggest that angiopoietin-1 supports SRC activities in human CD34(-) BM cells, as murine studies demonstrated. Furthermore, identification of previously undetected subpopulations of BM CD34(-) HSCs unveils heterogenous components in the stem cell pool.

Background: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell disorder caused by the clonal expansion of the phosphatidylinositol glycan class A (PIGA) mutant hematopoietic stem cells, which results in a deficiency in glycosylphosphatidylinositol-anchored proteins (GPI-APs). Through the high-resolution flow cytometry-based method, GPI-APs deficient blood cells (i.e., PNH-type cells) are often detectable in patients with bone marrow failure syndromes (BMF), such as aplastic anemia (AA) and low-risk types of myelodysplastic syndromes (MDS). Sugimori et al reported that when BMF patients possessed increased PNH-type cells, the patients had a good prognosis and showed a high response rate to immunosuppressive therapies, suggesting that detection of PNH-type cells is potentially useful in determining an optimal treatment for BMF patients. Thus, we conducted a nationwide, multi-center prospective observational investigation, the OPTIMA study. Methods: From July 2011, we start recruiting the patients with BMF that were diagnosed at various hematology clinics throughout Japan to the OPTIMA study. The primary endpoint of this study was to determine the prevalence of BMF patients with PNH-type cells and to clarify the clinical significance of the presence and quantitative changes of these cells with regard to the clinical features. Six different university laboratories were assigned as regional analyzing centers. The percentage of PNH-type cells was measured by the high-resolution flow cytometry-based method, originally established in Kanazawa University. At six individual laboratories, cross validations were conducted twice a year to minimize the inter-laboratory variations in the detection sensitivities, cutoff values, etc. The liquid FLAER method (≥0.003%) and cocktail method (≥0.005%) with CD55 and CD59 antibodies were used for the detection of PNH-type granulocytes and erythrocytes, respectively. Results Between July 2011 and May 2015, a total of 2328 patients were enrolled to this study, and we analyzed 2212 patients who were eligible for the interim analysis. Of these patients, 74 (3.3%) were diagnosed with PNH, 690 (31.2%) with AA, 592 (26.8%) with MDS, and 856 (38.7%) with undiagnosed BMF. Using high-resolution flow cytometry-based method, 755 (34.1%; 95.9% in PNH, 52.8% in AA, 18.2% in MDS, and 24.8% in undiagnosed BMT) patients had ≥0.005% PNH-type erythrocytes and ≥0.003% PNH-type granulocytes. Overall, 181(8.2%) patients had ≥1% of both PNH-type erythrocytes and granulocytes; the prevalence in each disease subset was 68/74 (91.9%) in PNH, 67/690 (9.7%) in AA, 22/592 (3.7%) in MDS, and 24/856 (2.8%) in undiagnosed BMF. Regarding FAB and WHO classifications of MDS subtype, no patients with RARS (0/22), RAEB-1 (0/37) or RAEB-2 (0/23) had PNH-type cells. In contrast, 20.4% (56/275) patients with RCMD, 18.3% (26/153) patients with RCUD and 50% (2/4) patients with del (5q) MDS possessed increased PNH-type cells. Blood samples from 75 (65 with and 10 without PNH-type cells) patients were analyzed three years after the first examination. Of 65 PNH (+) patients, PNH-type cells disappeared in 4 (6.2%), while the percentage remained stable in 61 (93.8%). All of the 10 PNH (-) at the enrollment were also negative for PNH-type cells in 3 years. Conclusions: A high-resolution flow cytometry-based method that enables the detection of minimal PNH-type cells below 0.01% was successfully transferred from Kanazawa University to other laboratories in Japan. Our interim analysis confirmed previous findings that PNH-type cells were detectable in patients with 52.8% of AA and 18.2% of MDS patients. Regarding FAB and WHO classifications of MDS subtype, PNH-type cells were not detected in any of MDS RARS, RAEB-1 or RAEB-2 patients. Further analysis are required to determine the clinical significance of the minimal level of PNH-type cells as well as chronological changes in the PNH-type cell percentage, especially in terms of their relation to response to immunosuppressive therapy. Disclosures Ninomiya: Alexion Pharmaceuticals: Honoraria. Ando:Eisai Co., Ltd.: Honoraria, Research Funding. Yonemura:1. Chugai Pharma, 2. Alexion Pharma, 3. Japan Blood Products Organization, 4. OHARA Pharma: Research Funding. Kawaguchi:Alexion Pharmaceuticals: Honoraria. Ueda:Alexion Pharma: Research Funding. Nishimura:Alexion Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

The American Society of Hematology guidelines recommend rituximab as second-line treatment, as well as splenectomy and thrombopoietin receptor agonists (TPO-RAs), for chronic immune thrombocytopenia (ITP). However, rituximab has not been approved for the treatment of chronic ITP in Japan. To establish chronic ITP as a new indication for rituximab, we conducted an investigator-initiated clinical trial to clarify the efficacy and safety of rituximab for Japanese patients with ITP. This study was designed as a single-arm, multicenter phase III study. Patients diagnosed with chronic ITP who were previously treated with at least one therapy for ITP and whose platelet count was ≤ 30,000/μL were included. Patients with a past history or current hepatitis B virus, hepatitis C virus or HIV infection, who were treated with splenectomy within 12 weeks or with TPO-RA within 4 weeks were excluded. Rituximab at a dose of 375 mg/m2was intravenously infused once weekly for 4 weeks. Patients were premedicated with acetaminophen, restamin and hydrocortisone to prevent infusion reactions. Platelet counts, bleeding symptoms, and B lymphocyte counts were observed once monthly following the protocol. The primary endpoint was the proportion of patients whose platelet count was ≥ 50,000/μL 24 weeks after treatment with rituximab. Between October 2011 and January 2013, 26 patients were enrolled in this study from 10 hospitals in Japan. Median age of the patients was 40 years and 89% were female. Baseline platelet counts were 23,000/μL. Median interval from diagnosis of ITP to commencing rituximab therapy was 5.9 years. Previous treatment of ITP was corticosteroids (69%), splenectomy (15%), TPO-RA (27%) and intravenous immunoglobulins (39%). At baseline, 58% of patients had some bleeding symptoms. Median number of previous ITP treatments was two. All patients completed the study. At 24 weeks after treatment, 30.8% (95% CI: 14.3–51.8%) of patients achieved platelet counts > 50,000/μL. Seven of eight responders demonstrated improvement until 8 weeks. Platelet count was significantly increased compared with baseline (P We demonstrated the efficacy and safety of rituximab in Japanese patients with chronic ITP. The response rate was similar to that in previous reports in the US and Europe. We plan to propose that the Japanese government approve chronic ITP as a new indication for rituximab. Disclosures: Miyakawa: Fuji film: Consultancy; Alexion pharmaceuticals: Honoraria; GlaxoSmithKline: Consultancy, Honoraria; KyowaHakkoKirin: Consultancy, Honoraria; Shire: Honoraria. Off Label Use: rituximab, clinical trial. Nishiwaki:Chugai pharmaceutical: Research Funding; Zenyaku Kogyo: Research Funding. Higashihara:Alexion: Honoraria; Asahi Kasei Pharma: Honoraria; Janssen pharma: Honoraria, Research Funding; Takeda: Honoraria; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Shionogi: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; GlaxoSmithKline: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; KyowaHakkoKirin: Honoraria, Research Funding; Boehringer-Ingeheim: Honoraria; Daiichi Sankyo: Honoraria; Yakurt: Honoraria; Astellas: Research Funding; Pfizer: Research Funding; Teijin: Research Funding; Meiji Seika pharma: Research Funding; Venesis: Research Funding; Baxter: Research Funding; Torii pharmaceutical: Research Funding; Bristol-Myers Squibb: Research Funding; Dainippon Sumitomo: Research Funding; Taiho: Research Funding; Taisho Tomiyama: Research Funding; MSD: Research Funding. Nishikawa:Daiichi-Sankyo: Research Funding. Ozaki:Chugai pharmaceutical: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Kyowa Hakko Kirin: Honoraria. Kanakura:Alexion Pharmaceuticals: Research Funding, Speakers Bureau. Okamoto:Novartis : Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; GlaxoSmithKlein: Honoraria, Research Funding; KyowaHakkoKirin: Honoraria, Research Funding; Chugai: Honoraria, Research Funding.

Abstract 691 Background: Tyrosine kinase inhibitor (TKI) therapy has become the standard treatment for patients with chronic phase chronic myelogenous leukemia (CML-CP). Compared with imatinib, dasatinib is known to induce a faster and better response as a first- and second-line treatment. A unique effect of dasatinib treatment is the induction of clonal lymphocytosis with large granular lymphocyte (LGL) morphology, presumed to be the effect of off-target kinase inhibition. These LGLs are known to possess either cytotoxic T-cell (CTL) or natural-killer (NK) cell phenotype. Several reports have shown that this clonal LGL expansion is associated with a better response to dasatinib treatment. Purpose: To prospectively analyze the immunoprofile of Japanese patients treated with dasatinib, and to correlate the increase of lymphocytes and their subsets (LGL, CTL and NK cells) with the clinical efficacy of dasatinib. Method and Patients: Japanese patients with CML-CP who were resistant or intolerant to first-line imatinib therapy participated in the prospective phase II study assessing the efficacy and safety of dasatinib. Peripheral blood LGL, CTL and NK cell counts before and 2 weeks, 1 month (M), 3M, and 6M after the initiation of treatment were analyzed at the central laboratory (BML Inc.) by flow cytometry. LGL, CTL and NK cells were defined as CD57+/CD14-, CD8+/CD4- and CD56+/CD3- cells, respectively. Lymphocytosis was defined as a lymphocyte count of >3.0×109/L. The clinical efficacy of dasatinib was evaluated at 12M as complete molecular response (CMR) or less than CMR by peripheral blood quantitative RT-PCR (BML Inc.). The full data set was available for 50 out of 65 patients and was included in this analysis. Results: The median age of the patients enrolled was 57 years (range: 16 – 87 years). There were 37 male and 13 female patients. Twenty patients were switched to dasatinib due to intolerance to imatinib and 30 due to resistance. Lymphocytosis was observed in 19 patients (38%) at 3M. Of those 19 patients, 14 (73.7%) had lymphocytosis persisting at 6M. In total, 21 patients (42%) achieved CMR at 12M. The absolute count of lymphocytes, LGL, CTL or NK cells, did not differ significantly between patients who achieved CMR at 12M and those who did not (p>0.05). However, there were significant differences between these two groups in the relative increase of these cell counts. Relative increase of lymphocytes compared to baseline as early as 2 weeks after initiation of treatment was identified by univariate analysis as a significant factor associated with CMR at 12M (p=0.0348). This increase persisted at each time point observed until 6M. As for the different subsets of lymphocytes, the relative increase of CTL at 3 and 6M and LGL at 1, 3 and 6M were also significantly associated with a higher rate of CMR at 12M. When adjusted for possible confounding factors (age, sex, performance status, whether 1st or 2nd CP, resistance or intolerance to imatinib), the relative increase of lymphocytes at 1, 3 and 6M, CTL and LGL at 3 and 6M remained significant (Fig a-c). Patients who showed an increase of lymphocytes of over 1.5-fold at 1M showed a significantly higher rate of CMR at 12M (66.7% vs 25.8%, p=0.0007). Similar differences were seen in patients with increases of over 2-fold in CTL, LGL and NK cells (70.6% vs 22.6%, p=0.0011; 74% vs 21%, p=0.0003; and 57.9% vs 28.6%, p=0.0444). Detailed analysis at 3M showed a further significant difference in the treatment effect. An increase of over 2-fold in lymphocytes (81.3% vs 21.2%, p Conclusion: Lymphocytosis after the initiation of dasatinib was seen in a substantial proportion of Japanese patients treated with dasatinib. A relative increase of lymphocytes together with LGL, CTL and NK cells, uniformly defined by flow cytometry, at 1 and 3M after the initiation of treatment were associated with a higher rate of CMR at 12M. To our knowledge, this is the first large prospective study analyzing the clinical significance of lymphocytosis associated with dasatinib therapy in Japanese patients with CML-CP using flow cytometry. Our results suggest that a relative increase of lymphocytes as early as 1M after the initiation of dasatinib is a reliable predictive marker for achieving CMR at 12M. Disclosures: No relevant conflicts of interest to declare.

Abstract 4448 Background Dasatinib is a potent tyrosine kinase inhibitor and is highly effective against chronic myeloid leukemia (CML). In Japan, dasatinib was approved in 2009 as a second-line therapy for CML after imatinib failure. Therefore, we conducted a phase II study to investigate the efficacy and safety of dasatinib treatment in Japanese CML-chronic phase (CP) patients with intolerance or resistance to imatinib. Patients and method CML-CP patients who were unable to continue imatinib therapy (400 mg/day) because of adverse events were registered as being intolerant to imatinib. Resistance to imatinib was defined as failure to achieve a partial cytogenetic response (PCyR) after three months of therapy or a complete cytogenetic response (CCyR) after six months of therapy or the expression of over 100 copies/μg RNA of BCR-ABL after 12 months of therapy. For these patients, dasatinib (100 mg) was administered once daily. Patients with T315I and F317I mutations in BCR-ABL were excluded. Major and complete molecular responses (MMR and CMR) were centrally evaluated using RQ-PCR at the BML laboratory. When the study was designed, a conversion factor (CF) had not been introduced to Japan for the adoption of international scale (IS). Subsequently, 0.1% IS (MMR) was defined as being equivalent to 731 copies/μg RNA based on the BML laboratory specific CF obtained in 2011, and 11 patients were identified as having an MMR at the time of study enrollment. Results A total of 61 patients were accrued from 21 centers: 26 with intolerance, and 35 with resistance. The median age was 58 years (range, 16 – 91 years). The median follow-up duration was nine months (range, 0.5 – 18 months). An MMR+CMR was observed in 27 out of 45 patients (60.0%, 13 CMR and 14 MMR) at six months and in 22 out of 31 patients (71.0%, 8 CMR and 14 MMR) at nine months after treatment with dasatinib, respectively. Excluding the patients with an MMR at the time of registration, dasatinib had induced an MMR+CMR in 21 out of 39 patients (53.9%, 11 CMR and 10 MMR) at six months and 19 out of 28 patients (67.9%, 7 CMR and 12 MMR) at nine months, respectively. The response rates in intolerant and resistant patients were comparable. Twelve patients discontinued dasatinib treatment because of drug toxicity (four patients), patient request (one), disease progression or the development of a T315I mutation (three), or unknown causes (four). Although grade 1 – 2 pleural effusion was observed in five patients, no severe cases were observed. Ten mutations in BCR-ABL occurred in eight patients during dasatinib treatment; a low IC50 of dasatinib against tumor cells in five of these mutations (M244V, M351T, F359I, F359V, H396R), an intermediate value against tumor cells in one of these mutations (Q252H), a high value against tumor cells in two of these mutations in three patients (T315I in two patients and E459K), and an unknown sensitivity against tumor cells in one of these mutations (A397P). Patients with M244V+Q252H, H396R, or T315I did not respond to dasatinib treatment. Conclusion Dasatinib is a safe and efficacious alternative for the treatment of CML following imatinib failure. Because MMR rate in the global study was 31% at one year and 44% at 5 years, the molecular response rate among Japanese patients was higher than that in western populations. Mutation in BCR-ABL remains a major issue. Disclosures: Okamoto: Bristol-Myers Squibb: Research Funding.

Abstract 3704 Introduction: Chronic immune thrombocytopenia (ITP) is an autoimmune disorder characterized by both increased platelet destruction and decreased platelet production. Romiplostim increases platelet counts by binding and activating the thrombopoietin receptor. Romiplostim has been approved for the treatment of adult ITP in the United States, Europe, Canada, and Australia. This study evaluated dosing, efficacy, and safety in a Japanese population of adults with ITP. Methods: This phase 3 study was placebo-controlled, double-blind, and randomized 2:1 (romiplostim:placebo). Patients were eligible for the study if they were Japanese patients with ITP diagnosed at least 6 months before the initial screening, were aged ≥ 20 years, and were H pylori negative or had received at least 1 treatment for H pylori eradication. Patients were stratified by splenectomy status (yes or no). After a 3-week evaluation period, patients were treated for 12 weeks with a weekly subcutaneous injection of either romiplostim or placebo. The starting dose was 3 mcg/kg with dose adjustments to a maximum of 10 mcg/kg to achieve a platelet count within the target range of ≥ 50 to ≤ 200 × 109/L. Patients were monitored posttreatment until their platelet count dropped to ≤ 50 × 109/L or for a maximum of 12 weeks. The primary endpoint was number of weeks with platelet response (platelet count ≥ 50 × 109/L). Results: Thirty-four patients enrolled (22 romiplostim, 12 placebo), 24 (71%) were female, the median (range) age was 55 (44 - 64) years, and the median (range) baseline platelet count was 19 (3 – 32) × 109/L. Patients had received a median of 4 (1 – 19) prior ITP therapies, and 15 (44%) had previously undergone a splenectomy; 23 (68%) patients were receiving concurrent ITP therapy at baseline. All patients completed the study. Romiplostim demonstrated superiority to placebo on weekly platelet response, incidence of increase in platelet count ≥ 20 × 109/L from baseline, change from baseline in mean of last 4 platelet counts during week 2 to week 13, and number of weeks with platelet counts within the target range (Table 1), and 16 (73%) romiplostim patients had platelet counts ≥ 200 × 109/L. Twenty-one (95%) patients in the romiplostim group had a platelet response with a median time of 1 week until first response. Results for weekly platelet response were comparable irrespective of splenectomy status and baseline concurrent ITP therapy. Two (17%) patients in the placebo group achieved a platelet response. In romiplostim-treated patients, posttreatment platelet counts remained > 50 × 109/L for 8 weeks in one and for 12 weeks in another. The mean weekly dose of romiplostim for the study was 2.6 mcg/kg compared with the dose range of 3–4 mcg/kg in prior phase 3 studies (Kuter et al. Lancet. 2008;371:395–403). There was a low incidence of rescue medication use in the study (Table 1). The adverse events profile was comparable to that seen in non-Japanese studies. Patients in both treatment groups experienced similar proportions of adverse events (91% romiplostim, 92% placebo). Adverse events with > 10% higher frequency in the romiplostim group than placebo group) were (romiplostim, placebo) nasopharyngitis (41%, 17%), headache (32%, 17%), peripheral edema (18%, 0%), back pain (14%, 0%), and pain in extremity (14%, 0%). Significant (≥ grade 3) bleeding events occurred in 1 patient in the romiplostim group (subarachnoid hemorrhage) and 1 patient in the placebo group (subarachnoid hemorrhage, cerebral hemorrhage, and gastrointestinal hemorrhage). There were no adverse events of bone marrow reticulin, thrombosis, or detection of neutralizing antibodies. Table 1 . Study Efficacy Endpoints Romiplostim N = 22 Placebo N = 12 p Value Primary end point Weekly platelet response: platelet count of ≥ 50 × 109/L, median (Q1, Q3) 11.0 wk (9, 12) 0.0 wk (0, 0) Secondary end points Proportion of patients with increase of platelet count ≥ 20 × 109/L from baseline, incidence rate, n (%) 21 (96) 3 (25) Change from baseline in mean of last 4 platelet counts during weeks 2–13, mean (SD) 110 (89) × 109/L 2 (7) × 109/L 0.0003 Number of weeks with platelet counts in target range of ≥ 50 to ≤ 200 × 109/L, median (Q1, Q3) 7 (3, 9) wk 0 (0, 0) wk Proportion of patients requiring rescue medications, incidence rate, n (%) 2u(9) 2u(17) 0.6015 Conclusion: Romiplostim significantly increased and maintained platelet counts and was well-tolerated in a Japanese ITP population. Disclosures: Tomiyama: Kyowa Hakko Kirin Co.: Speakers Bureau; GlaxoSmithKline: Speakers Bureau. Kurokawa: Novartis: Consultancy; Shionogi & Co., Ltd.: Consultancy. Wei: Amgen Inc.: Employment, Equity Ownership. Lizambri: Amgen Inc.: Employment, Equity Ownership.