No abstract

Japan Pharmacogenomics Data Science Consortium (JPDSC) has assembled a database for conducting pharmacogenomics (PGx) studies in Japanese subjects. The database contains the genotypes of 2.5 million single-nucleotide polymorphisms (SNPs) and 5 human leukocyte antigen loci from 2994 Japanese healthy volunteers, as well as 121 kinds of clinical information, including self-reports, physiological data, hematological data and biochemical data. In this article, the reliability of our data was evaluated by principal component analysis (PCA) and association analysis for hematological and biochemical traits by using genome-wide SNP data. PCA of the SNPs showed that all the samples were collected from the Japanese population and that the samples were separated into two major clusters by birthplace, Okinawa and other than Okinawa, as had been previously reported. Among 87 SNPs that have been reported to be associated with 18 hematological and biochemical traits in genome-wide association studies (GWAS), the associations of 56 SNPs were replicated using our data base. Statistical power simulations showed that the sample size of the JPDSC control database is large enough to detect genetic markers having a relatively strong association even when the case sample size is small. The JPDSC database will be useful as control data for conducting PGx studies to explore genetic markers to improve the safety and efficacy of drugs either during clinical development or in post-marketing.

Multiple myeloma (MM) is an incurable hematological malignancy caused by accumulation of abnormal clonal plasma cells. Despite the recent development of novel therapies, relapse of MM eventually occurs as a result of a remaining population of drug‐resistant myeloma stem cells. Side population (SP) cells show cancer stem cell‐like characteristics in MM; thus, targeting these cells is a promising strategy to completely cure this malignancy. Herein, we showed that SP cells expressed higher levels of enhancer of zeste homolog (EZH) 1 and EZH2, which encode the catalytic subunits of Polycomb repressive complex 2 (PRC2), than non‐SP cells, suggesting that EZH1 as well as EZH2 contributes to the stemness maintenance of the MM cells and that targeting both EZH1/2 is potentially a significant therapeutic approach for eradicating myeloma stem cells. A novel orally bioavailable EZH1/2 dual inhibitor, OR‐S1, effectively eradicated SP cells and had a greater antitumor effect than a selective EZH2 inhibitor in vitro and in vivo, including a unique patient‐derived xenograft model. Moreover, long‐term continuous dosing of OR‐S1 completely cured mice bearing orthotopic xenografts. Additionally, PRC2 directly regulated WNT signaling in MM, and overactivation of this signaling induced by dual inhibition of EZH1/2 eradicated myeloma stem cells and negatively affected tumorigenesis, suggesting that repression of WNT signaling by PRC2 plays an important role in stemness maintenance of MM cells. Our results show the role of EZH1/2 in the maintenance of myeloma stem cells and provide a preclinical rationale for therapeutic application of OR‐S1, leading to significant advances in the treatment of MM.

Enhancer of zeste homolog (EZH) 1 and its close homolog EZH2 are component of polycomb repressive complex 2 (PRC2), and play a partially redundant and crucial role for the maintenance of transcriptional repression by tri-methylating histone H3 lysine 27 (H3K27). Hyper tri-methylation of H3K27 have been associated with lymphoma and myeloma progression, suggesting PRC2 is a therapeutic target for hematological malignancies. We have developed a novel EZH1 and EZH2 dual inhibitor valemetostat (DS-3201b), which simultaneously inhibited the enzymatic activity of EZH1 and EZH2 in nano-molar concentration. Valemetostat demonstrated anti-proliferative activities against the Activated B-cell-like (ABC) and Germinal Center B-cell-like (GCB) subtypes of Diffuse Large B-cell Lymphoma (DLBCL) cells. Furthermore, valemetostat induced apoptosis in DLBCL cell lines, regardless of subtype. We revealed that the pleiotropic effects of valemetostat on the expression levels of B-cell receptor signaling molecules by western blotting analysis. In particular, valemetostat suppressed the expression level of BCL6 protein, a key oncogene in B cell lymphoma. Transcriptome analysis of 16 DLBCL cell lines using RNA sequencing suggested that tumor suppressor genes, DNA damage response related genes and cell cycle related genes were affected by valemetostat treatment. In particular, valemetostat down regulated c-myc signaling in valemetostat-sensitive cells. Valemetostat also demonstrated synergistic anti-tumor activity with standard of care therapy against a DLBCL cell line KARPAS-422 xenografted model. In conclusion, our results suggested that valemetostat has therapeutic activity in DLBCL cells by inhibiting B-cell receptor signaling and c-myc signaling pathway. A phase 1 clinical study of valemetostat mono-therapy is now ongoing in patients with non-Hodgkin lymphoma including DLBCL (Clinical trial information: NCT02732275). Disclosures Hama: Daiichi Sankyo Co., Ltd.: Employment. Banjo:Daiichi Sankyo Co., Ltd.: Employment. Honma:Daiichi Sankyo Co., Ltd.: Employment. Takata:Daiichi Sankyo Co., Ltd.: Employment. Nosaka:Daiichi Sankyo Co., Ltd.: Employment. Shiroishi:Daiichi Sankyo Co., Ltd.: Employment. Watanabe:Daiichi Sankyo Co., Ltd.: Employment. Yamamoto:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Hirata:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Nakano:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Inaki:Daiichi Sankyo Co., Ltd.: Employment. Goto:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Totoki:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Kataoka:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Lim:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Wada:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Kumazawa:Daiichi Sankyo RD Novare Co., Ltd.: Employment. Tsutsumi:Daiichi Sankyo Co., Ltd.: Employment.

mutation group compared with the wild group (median 32m vs 19m) (P¼0.05). No significant survival difference between KRAS mutation and wild group was found (P>0.05). Among EGFR wild advanced NSCLC patients, the median OS of KRAS mutation group was 13 months while that of wild group was 26 months, but there was no significant difference (P>0.05). Multivariant analyzes showed gender, TKI treatment history and smoking history were independent prognostic factors in NSCLC (P<0.05). Conclusion: EGFR mutation is the most common driver gene in Chinese NSCLC, especially in adenocarcinoma patients, which often occurs in exon 19, 20 and 21 region. Then followed by KRAS mutation, it mostly occurs in exon 2. MET gene exon14 skipping is common in patients with adenocarcinoma or post-TKI treatment, which may be related to TKI resistance. Gender, smoking history and TKI treatment history could be independent prognostic factors in NSCLC.