Cytomegalovirus infection in patients with malignant lymphomas who have not received hematopoietic stem cell transplantation.

BACKGROUND: Life-threatening cytomegalovirus infection (CMVI) has been reported even in patients with malignant lymphoma (ML) who have not received hematopoietic stem cell transplantation (w/o HSCT) but had been treated with chemotherapy or radiotherapy. However, the CMVI incidence and risk factors (RFs) in patients with ML w/o HSCT have not been fully elucidated. This study aimed to evaluate the clinical aspects, including incidence and RFs, of CMVI in patients with ML w/o HSCT. METHODS: We retrospectively reviewed all patients with ML who received chemotherapy or radiotherapy in our department from 2005 to 2013. The overall survival (OS), incidence and RFs of CMVI, and other characteristics of patients with CMVI were analyzed. RESULTS: Overall, 236 patients with ML w/o HSCT were evaluated. Of these, 5.5% (13/236) developed CMVI; 54% (7/13) received steroid pretreatment before primary therapy (PT) for ML; and 62% (8/13) received > 2 therapeutic regimens for ML. The OS curve of patients with CMVI was significantly worse than that of patients without CMVI (p < 0.0001, log-rank test). A univariate analysis identified B symptoms (p = 0.00321), serum albumin < 3.5 g/dL (p = 0.0007837), C-reactive protein level > the upper limit of normal (p = 0.0006962), steroid pretreatment before PT for ML (p = 0.0004262), > 2 therapeutic regimens for ML (p = 0.0000818), T cell lymphoma (p = 0.006406), and non-complete remission (p = 0.02311) as RFs for CMVI. A multivariate analysis identified steroid pretreatment before PT for ML [odds ratio (OR): 4.71 (95% confidence interval [CI]: 1.06-21.0); p = 0.0419] and > 2 therapeutic regimens for ML [OR: 9.25 (95% CI: 2.33-36.8); p = 0.00159] as independent RFs for CMVI in patients with ML w/o HSCT. CONCLUSIONS: Attention should be paid to CMVI development in patients with ML w/o HSCT pretreated with steroids or who had multiple therapeutic regimens.

Successful Treatment of Myeloid Sarcoma in an Elderly Patient with Myelodysplastic Syndrome with Reduced-Dose Azacitidine.

Myeloid sarcoma (MS), which involves extramedullary lesions, is classified as a unique subtype of acute myeloid leukemia (AML). At present, no standard treatments for MS have been established. The patient was an 89-year-old man with myelodysplastic syndrome-excess blast-2 (MDS-EB-2) with a 2-year history of intermittent treatment with azacitidine (AZA) during a 4-year history of MDS. He developed painful cutaneous tumors 8 months after the second discontinuation of AZA. They were refractory for antibiotics and topical tacrolimus hydrate. A tumor biopsy was performed, and the histological findings of the tumor lesion showed a proliferation of tumor cells that were positive for myeloperoxidase and CD68 and negative for CD4 and CD123. The patient was diagnosed with MDS-associated MS. MDS-EB-2 quickly progressed to AML with the appearance of peripheral blood blasts and 25% bone marrow blasts. Monotherapy with reduced-dose AZA (37.5 mg/m2 for 7 days, every 4-6 weeks) was restarted, and the MS quickly disappeared. The patient's MS was successfully treated with 16 cycles of AZA treatment over a 22-month period. There have been 10 reported cases in which MS was successfully treated with AZA. Among the 10 cases, the patient in the present case was the oldest. Treatment with reduced-dose AZA should be considered as a therapeutic option for MS in elderly patients with MDS, especially patients who are ineligible for intensive chemotherapy.

Acquired hemophilia A associated with Epstein-Barr-virus-associated T/natural killer-cell lymphoproliferative disease: A case report.

INTRODUCTION: Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against factor VIII (FVIII). Hematological malignancies, especially lymphoid malignancies, are known to be underlying causes of AHA; however, thus far, there is no report of AHA associated with Epstein-Barr-virus-associated T/natural killer-cell lymphoproliferative disease (EBV-T/NK-LPD). Here, we present a case of AHA that developed during treatment for EBV-T/NK-LPD. HISTORY: A 69-year-old man visited our hospital because of general fatigue. Blood examination showed pancytopenia, and computed tomography revealed whole-body lymphadenopathy, but there were no findings indicating hematological malignancy from bone marrow aspiration and cervical lymph node biopsy. The level of EBV DNA in peripheral blood was extremely high, and he was diagnosed with EBV-T/NK-LPD. EBV-T/NK-LPD improved with prednisolone (PSL) administration. Seventeen months after starting treatment, the patient complained of back and right leg pain. At that time, he had been treated with low-dose PSL, and EBV-T/NK-LPD was well controlled. Imaging revealed hematoma of the right iliopsoas muscle. Prolonged activated partial thromboplastin time (APTT) was the only abnormal finding in a screening coagulation test. FVIII coagulant activity was below detection limit, and FVIII inhibitor level was increased. From these results, he was diagnosed with AHA.A higher dose of PSL was administered, and, after 1 month of treatment, FVIII activity gradually increased, and FVIII inhibitor level became undetectable. APTT also normalized, and complete remission was achieved and maintained for 13 months with low-dose PSL. During treatment, EBV-T/NK-LPD was well controlled. CONCLUSION: It is speculated that proliferating lymphocytes interfere with normal immune functions and that abnormal autoantibodies are produced from those lymphocytes in patients with LPD. Therefore, we speculate that EBV-infected and proliferating monoclonal NK cells might have modulated the immune system and produced autoantibodies against FVIII, thus causing AHA in this patient with EBV-T/NK-LPD.

Clinical significance of comprehensive genomic profiling tests covered by public insurance in patients with advanced solid cancers in Hokkaido, Japan.

BACKGROUND: Comprehensive cancer genomic profiling has been used recently for patients with advanced solid cancers. Two cancer genomic profiling tests for patients with no standard treatment are covered by Japanese public health insurance since June 2019. METHODS: We prospectively analyzed data of 189 patients with solid cancers who underwent either of the two-cancer genomic profiling tests at Hokkaido University Hospital and its liaison hospitals and whose results were discussed in molecular tumor board at Hokkaido University Hospital between August 2019 and July 2020. RESULTS: All 189 patients had appropriate results. Actionable gene alterations were identified in 93 patients (49%). Frequent mutations included PIK3CA (12%) mutation, BRCA1/2 alteration (7%), ERBB2 amplification (6%) and tumor mutation burden-High (4%). The median turnaround time from sample shipping to acquisition by the expert panel was 26 days. Although 115 patients (61%) were provided with information for genotype-matched therapies, only 21 (11%) received them. Notably, four of eight patients below the age of 20 years were provided information for genotype-matched therapies, and three received them. Their response rates and disease control rates were 29% and 67%, respectively. Most patients who did not undergo the genotype-matched therapies were provided information for only investigational drugs in phases I and II at distant clinical trial sites in central Japan. Twenty-six patients were informed of suspected germline findings, while 11 patients (42%) received genetic counseling. CONCLUSIONS: The publicly reimbursed cancer genomic profilings may lead to the modest but favorable therapeutic efficacy of genotype-matched therapy for solid cancer patients with no standard therapy. However, poor access to genotype-matched therapy needs to be resolved.

Genetic analysis of postoperative recurrence of pancreatic cancer potentially owing to needle tract seeding during EUS-FNB.

Background and study aims Needle tract seeding during endoscopic ultrasound fine-needle biopsy (EUS-FNB) remains a concern. We investigated whether such seeding occurred in a patient with pancreatic ductal adenocarcinoma (PDA). Patient and methods Surgically resected and EUS-FNB-derived specimens were genotyped to determine if a gastric wall tumor that emerged 3 years after curative resection of an early-stage PDA was clonally related to the original tumor. Results The gastric tumor histologically resembled the primary PDA; the lesions also shared KRAS , SMAD4 , and RNF43 mutations. Genotyping of the preoperative EUS-FNB specimen, in which cancer was not detected, nevertheless revealed mutations that were identical to those in the resected primary and recurrent tumors. While the primary PDA had a low frequency of mutant SMAD4 , such mutations were highly prevalent in both the EUS-FNB and recurrent tumor specimens. Conclusions The genetic lineages of sampled tissues from our patient revealed that needle tract seeding may have incidentally occurred when a subset of neoplastic cells within a heterogeneous tumor ( i. e. , an aggressive clone) was targeted during EUS-FNB.

Pseudogout Attack after Pegfilgrastim Administration in Anaplastic Large Cell Lymphoma.

A 67-year-old man with relapsed anaplastic large cell lymphoma received salvage chemotherapy, and pegfilgrastim was used to prevent febrile neutropenia. On day 18 of chemotherapy, he developed a pseudogout attack. Although the first symptoms improved, another pseudogout attack occurred when he received the second course of chemotherapy and pegfilgrastim. Filgrastim was then used for the third course of chemotherapy, and a pseudogout attack did not occur. The serum granulocyte-stimulating factor (G-CSF) level was extremely elevated only when pegfilgrastim was used, suggesting a relationship between pseudogout and G-CSF. Pseudogout should be recognized as an adverse effect of pegfilgrastim.

A nationwide survey of hypoplastic myelodysplastic syndrome (a multicenter retrospective study).

Hypoplastic myelodysplastic syndrome (hMDS) is a distinct entity with bone marrow (BM) hypocellularity and the risk of death from BM failure (BMF). To elucidate the characteristics of hMDS, the data of 129 patients diagnosed between April 2003 and March 2012 were collected from 20 institutions and the central review team of the National Research Group on Idiopathic Bone Marrow Failure Syndromes, and compared with 115 non-hMDS patients. More RA and fewer CMMoL and RAEB-t in French-American-British (FAB) and more RCUD and MDS-U and fewer RCMD in World Health Organization (WHO) classifications were found in hMDS than non-hMDS with significant differences. The overall survival (OS) and AML progression-free survival (AML-PFS) of hMDS were higher than those of non-hMDS, especially in patients at age ≥50 and of lower risk in Revised International Prognostic Scoring System (IPSS-R). In competing risks analysis, hMDS exhibited decreased risk of AML-progression in lower IPSS or IPSS-R risk patients, and higher risk of death from BMF in patients at age ≥50. Poor performance status (PS ≥2) and high karyotype risks in IPSS-R (high and very high) were significant risk factors of death and AML-progression in Cox proportional hazards analysis.

Angioimmunoblastic T-cell lymphoma and hypereosinophilic syndrome with FIP1L1/PDGFRA fusion gene effectively treated with imatinib: A case report.

RATIONALE: Hypereosinophilic syndrome (HES) is a rare disorder characterized by hypereosinophilia and organ damage. Some cases of HES are caused by the FIP1L1/PDGFRA fusion gene and respond to imatinib. FIP1L1/PDGFRA-positive HES occasionally evolves into chronic eosinophilic leukemia or into another form of myeloproliferative neoplasm; however, the development of a malignant lymphoma is very rare. We present a rare case of angioimmunoblastic T-cell lymphoma (AITL) and HES with the FIP1L1/PDGFRA gene rearrangement. PATIENT CONCERNS: A man in his 30s presented to our hospital with fever, hypereosinophilia, widespread lymphadenopathy, and splenomegaly. Laboratory tests showed hypereosinophilia, increased soluble interleukin-2 receptor, and increased vitamin B12. Positron-emission tomography with F fluorodeoxyglucose (FDG) showed positive FDG uptake in multiple enlarged lymph nodes throughout the body and the red bone marrow. A bone-marrow biopsy showed hypereosinophilia without dysplasia and an increased number of blasts. The FIP1L1/PDGFRA fusion gene was positive upon fluorescence in situ hybridization (FISH) analysis of the peripheral blood. Furthermore, biopsy of a lymph node from the neck revealed restiform hyperplasia of capillary vessels, with small lymphoma cells arranged around the capillaries. Lymphoma cells were positive for CD3, CD4, and CD10, and negative for CD20. Lymphoma cells were also positive for the FIP1L1/PDGFRA fusion gene by FISH analysis. DIAGNOSES: From these findings, the patient was diagnosed with HES and AITL with FIP1L1/PDGFRA. INTERVENTIONS: After the diagnosis, corticosteroid was administered but was ineffective. Imatinib was then administered. OUTCOMES: Imatinib was very effective for treating HES and AITL, and complete remission was achieved in both. LESSONS: This report presents the first case in which the FIP1L1/PDGFRA fusion gene was positive both in peripheral blood and lymph nodes, implying the possibility that the tumor cells acquired the FIP1L1/PDGFRA fusion gene in the early stage of hematopoietic progenitor cell developments. Imatinib was very effective in treating both HES and lymphoma, suggesting that the FIP1L1/PDGFRA fusion gene plays a key role in the pathogenesis of both HES and lymphoma.

A Multicenter Retrospective Study of Mogamulizumab Efficacy in Adult T-Cell Leukemia/Lymphoma.

BACKGROUND: Mogamulizumab, a defucosylated humanized monoclonal antibody targeting C-C chemokine receptor 4, recently became available for the treatment of adult T-cell leukemia/lymphoma (ATL). We conducted a multicenter retrospective study of the efficacy of mogamulizumab in ATL treatment in patients on Hokkaido Island, Japan. MATERIALS AND METHODS: A total of 125 patients with ATL treated from January 2010 to December 2014 in 20 hospitals affiliated with the Hokkaido Hematology Study Group were enrolled in the present retrospective study. RESULTS: Of the 125 ATL patients, 62 (46.6%) presented with the acute type, 51 (38.3%) with the lymphoma type, and 12 (9.0%) with the chronic type; the latter group included 7 unfavorable chronic cases. The median age at diagnosis was 68 years (range, 35-86 years). The median survival for those with acute, lymphoma, and unfavorable chronic types was 302, 279, and 921 days, respectively. Advanced age, high lactate dehydrogenase level, poor performance status (3-4), and the existence of B symptoms were unfavorable prognostic factors for overall survival (OS). Survival rate calculated from the day of diagnosis was significantly higher in patients treated with mogamulizumab. The OS of individuals receiving hematopoietic stem cell transplantation (HSCT) was superior to that of the non-HSCT group. The median interval between the last mogamulizumab dose and allogeneic HSCT was 38 days (range, 21-53 days). Of the 22 HSCT recipients who were not treated with mogamulizumab, overall acute graft-versus-host disease (aGVHD) and grade III-IV aGVHD occurred in 12 (54.5%) and 3 (13.6%) patients, respectively. However, overall aGVHD and grade III-IV aGVHD developed in 8 (88.9%) and 3 (33.3%) of the 9 HSCT recipients treated with mogamulizumab, respectively. CONCLUSION: Mogamulizumab improves OS in patients with ATL, although its use in HSCT patients might trigger severe GVHD. Determining the optimal pre-HSCT mogamulizumab treatment regimen is thus a priority.

Iron-induced epigenetic abnormalities of mouse bone marrow through aberrant activation of aconitase and isocitrate dehydrogenase.

Iron overload remains a concern in myelodysplastic syndrome (MDS) patients. Iron chelation therapy (ICT) thus plays an integral role in the management of these patients. Moreover, ICT has been shown to prolong leukemia-free survival in MDS patients; however, the mechanisms responsible for this effect are unclear. Iron is a key molecule for regulating cytosolic aconitase 1 (ACO1). Additionally, the mutation of isocitrate dehydrogenase (IDH), the enzyme downstream of ACO1 in the TCA cycle, is associated with epigenetic abnormalities secondary to 2-hydroxyglutarate (2-HG) and DNA methylation. However, epigenetic abnormalities observed in many MDS patients occur without IDH mutation. We hypothesized that iron itself activates the ACO1-IDH pathway, which may increase 2-HG and DNA methylation, and eventually contribute to leukemogenesis without IDH mutation. Using whole RNA sequencing of bone marrow cells in iron-overloaded mice, we observed that the enzymes, phosphoglucomutase 1, glycogen debranching enzyme, and isocitrate dehydrogenase 1 (Idh1), which are involved in glycogen and glucose metabolism, were increased. Digital PCR further showed that Idh1 and Aco1, enzymes involved in the TCA cycle, were also elevated. Additionally, enzymatic activities of TCA cycle and methylated DNA were increased. Iron chelation reversed these phenomena. In conclusion, iron activation of glucose metabolism causes an increase of 2-HG and DNA methylation.

A selective splicing variant of hepcidin mRNA in hepatocellular carcinoma cell lines.

Hepcidin is a main regulator of iron metabolism, of which abnormal expression affects intestinal absorption and reticuloendothelial sequestration of iron by interacting with ferroportin. It is also noted that abnormal iron accumulation is one of the key factors to facilitate promotion and progression of cancer including hepatoma. By RT-PCR/agarose gel electrophoresis of hepcidin mRNA in a hepatocellular carcinoma cell line HLF, a smaller mRNA band was shown in addition to the wild-type hepcidin mRNA. From sequencing analysis, this additional band was a selective splicing variant of hepcidin mRNA lacking exon 2 of HAMP gene, producing the transcript that encodes truncated peptide lacking 20 amino acids at the middle of preprohepcidin. In the present study, we used the digital PCR, because such a small amount of variant mRNA was difficult to quantitate by the conventional RT-PCR amplification. Among seven hepatoma-derived cell lines, six cell lines have significant copy numbers of this variant mRNA, but not in one cell line. In the transient transfection analysis of variant-type hepcidin cDNA, truncated preprohepcidin has a different character comparing with native preprohepcidin: its product is insensitive to digestion, and secreted into the medium as a whole preprohepcidin form without maturation. Loss or reduction of function of HAMP gene by aberrantly splicing may be a suitable phenomenon to obtain the proliferating advantage of hepatoma cells.

Current therapeutic strategies for multiple myeloma.

The introduction of novel molecular targeting agents against multiple myeloma has dramatically and rapidly changed the therapeutic strategies for this incurable hematologic disease. Novel agents such as thalidomide, bortezomib and lenalidomide have significantly improved the response rate, progression-free survival, and overall survival compared with conventional chemotherapies, and made it easy to control the disease for longer periods of time. Initial therapies for newly diagnosed myeloma patients depend on the individual's clinical condition. Induction therapy with novel agents and high-dose chemotherapy followed by autologous stem cell transplantation is a standard therapy for newly diagnosed younger myeloma patients. On the other hand, several combinations of novel agents and other drugs (melphalan, prednisone, dexamethasone, etc.) are widely used as initial therapy for transplantation-ineligible myeloma patients. Although the clinical advantage of maintenance therapy after induction therapy has been reported, it is not recommend in routine practice. Maintenance therapy would be an option for some patients. Despite the significant improvements with the use of novel agents, the majority of patients eventually relapse. A number of treatment options including novel agents, which demonstrated marked clinical effects, are reported in the setting of salvage therapy. The choice of appropriate therapy for relapsed or refractory patients must take the disease status or patient status in consideration. Furthermore, a new generation of novel agents such as pomalidomide, carfilzomib or panobinostat has recently become available for relapsed or refractory myeloma. It is necessary to determine the optimal combination of drugs, administration timing and patients to be treated in future clinical trials.

Hepatic nerve growth factor induced by iron overload triggers defenestration in liver sinusoidal endothelial cells.

The fenestrations of liver sinusoidal endothelial cells (LSECs) play important roles in the exchange of macromolecules, solutes, and fluid between blood and surrounding liver tissues in response to hepatotoxic drugs, toxins, and oxidative stress. As excess iron is a hepatotoxin, LSECs may be affected by excess iron. In this study, we found a novel link between LSEC defenestration and hepatic nerve growth factor (NGF) in iron-overloaded mice. By Western blotting, NGF was highly expressed, whereas VEGF and HGF were not, and hepatic NGF mRNA levels were increased according to digital PCR. Immunohistochemically, NGF staining was localized in hepatocytes, while TrkA, an NGF receptor, was localized in LSECs. Scanning electron microscopy revealed LSEC defenestration in mice overloaded with iron as well as mice treated with recombinant NGF. Treatment with conditioned medium from iron-overloaded primary hepatocytes reduced primary LSEC fenestrations, while treatment with an anti-NGF neutralizing antibody or TrkA inhibitor, K252a, reversed this effect. However, iron-loaded medium itself did not reduce fenestration. In conclusion, iron accumulation induces NGF expression in hepatocytes, which in turn leads to LSEC defenestration via TrkA. This novel link between iron and NGF may aid our understanding of the development of chronic liver disease.

Long-term survey of survival time, histological transformation, and secondary malignancies in Japanese patients with advanced-stage follicular lymphoma in the rituximab era: Hokkaido Hematology Study Group.

Following the introduction of rituximab, the long-term overall survival (OS) rate of advanced-stage follicular lymphoma (FL) cases was expected to improve after the introduction of rituximab: however, there is a lack of large-scale survey data in Asia due to the relatively low incidence of FL. We conducted a retrospective survey to assess the treatment outcomes in patients with newly diagnosed advanced-stage FL in 29 institutions in Hokkaido from January 2001 to December 2010. The total number of patients was 443 (men 47.6%, women 52.4%), with a median age of 55 years (range 20-80 years). Of the cases examined, 42.2% had stage III and 57.8% had stage IV disease. Furthermore, 62.5, 19.7, 9.2, 5.2, and 3.4% had performance statuses of 0, 1, 2, 3, and 4, respectively. The 5-year OS was 91.2%, and no survival plateau was observed. Seventeen patients experienced secondary malignancies (six hematological diseases and 11 solid cancers; 5-year probability, 4.2%). Eighteen patients experienced transformation (5-year probability, 4.5%). The overall survival at 5 years after therapy for transformation was 50%. Before the introduction of rituximab, the 5- to 10-year OS of advanced-stage FL patients in Japan was reported to be about 30-60%. Although these data are limited, improvement in OS has been observed in Japan during the rituximab era.

Non-transferrin-bound iron assay system utilizing a conventional automated analyzer.

BACKGROUND: Iron is an essential metal in the body, but its excessive accumulation causes damage in various organs through free radical production. Iron homeostasis is therefore tightly regulated. However, when iron balance collapses, such as in prolonged transfusion, transferrin (Tf) is fully saturated and non-Tf-bound iron (NTBI) appears in the serum. Monitoring serum NTBI levels is therefore crucial in the assessment of the clinical status of patients with iron overload, since NTBI is associated with cellular and organ damage. Several methods for NTBI determination have been reported, but these are extremely complicated and very few laboratories can quantify NTBI at present. METHODS: We established a novel assay system utilizing automated analyzers that are widely used in clinical laboratories for diagnostic testing. In this assay, NTBI is chelated by nitrilotriacetic acid (NTA), after which the iron is reduced and transferred to nitroso-PSAP, a chromogen. RESULTS: The assay shows excellent linearity, reproducibility, and compatibility with HPLC, one of the most reliable conventional methods for NTBI quantification. CONCLUSIONS: Our novel method for NTBI measurement is high-throughput and may be a useful and powerful tool in the study of the physiological and clinical importance of NTBI.

Risk factor analysis of non-Hodgkin lymphoma-associated haemophagocytic syndromes: a multicentre study.

Haemophagocytic syndrome is often associated with malignant lymphoma; however, few studies have examined lymphoma-associated haemophagocytic syndrome (LAHS). A total of 1239 patients with non-Hodgkin lymphoma were analysed at 12 institutions in Hokkaido prefecture between January 2007 and December 2011 to assess the incidence, prognosis and risk factors of LAHS. The cumulative incidence rate of LAHS was 2·8% (35/1239). Overall survival (OS) in patients with LAHS was significantly inferior to those without LAHS (3-year OS: 35·6 vs. 59·0% respectively, P < 0·0001). The cumulative incidence of LAHS was higher in patients with T/Natural Killer (NK)-cell lymphoma than in those with B-cell lymphoma (8·2 vs. 1·8% respectively, P < 0·0001). The characteristics of patients with and without early death (within the first 120 d after developing LAHS) were subsequently compared to evaluate the prognostic factor of LAHS. The results obtained showed that the rate of early death after developing LAHS was higher in patients with T/NK-cell lymphoma than in those with B-cell lymphoma (62·5 vs. 10·5%, P = 0·0033). In conclusion, the complication and mortality rates of LAHS were higher in patients with T/NK-cell lymphoma after they developed LAHS than in those with B-cell lymphoma.

Multicenter phase II clinical trial of nilotinib for patients with imatinib-resistant or -intolerant chronic myeloid leukemia from the East Japan CML study group evaluation of molecular response and the efficacy and safety of nilotinib.

BACKGROUND: Nilotinib is a second-generation tyrosine kinase inhibitor that exhibits significant efficacy as first- or second-line treatment in patients with chronic myeloid leukemia (CML). We conducted a multicenter Phase II Clinical Trial to evaluate the safety and efficacy of nilotinib among Japanese patients with imatinib-resistant or -intolerant CML-chronic phase (CP) or accelerated phase (AP). RESULTS: We analyzed 49 patients (33 imatinib-resistant and 16 imatinib-intolerant) treated with nilotinib 400 mg twice daily. The major molecular response (MMR) rate was 47.8% at 12 months among 35 patients who did not demonstrate an MMR at study entry. Somatic BCR-ABL1 mutations (Y253H, I418V, and exon 8/9 35-bp insertion [35INS]) were detected in 3 patients at 12 months or upon discontinuation of nilotinib. Although 75.5% of patients were still being treated at 12 months, nilotinib treatment was discontinued because of progressing disease in 1 patient, insufficient effect in 2, and adverse events in 9. There was no statistically significant correlation between MMR and trough concentrations of nilotinib. Similarly, no correlation was observed between trough concentrations and adverse events, except for pruritus and hypokalemia. Hyperbilirubinemia was frequently observed (all grades, 51.0%; grades 2-4, 29%; grades 3-4, 4.1%). Hyperbilirubinemia higher than grade 2 was significantly associated with the uridine diphosphate glucuronosyltransferase (UGT)1A9 I399C/C genotype (P = 0.0086; Odds Ratio, 21.2; 95% Confidence Interval 2.2-208.0). CONCLUSIONS: Nilotinib was efficacious and well tolerated by patients with imatinib-resistant or -intolerant CML-CP/AP. Hyperbilirubinemia may be predicted before nilotinib treatment, and may be controlled by reducing the daily dose of nilotinib in patients with UGT1A9 polymorphisms. TRIAL REGISTRATION: clinicaltrials.gov: UMIN000002201.