Abstract: Previous studies have shown that the cyclin-dependent kinase inhibitor (CDKI) genes p15INK4B and p16INK4A are frequently inactivated by genetic alterations in many malignant tumors and that they are candidate tumor-suppressor genes. Although genetic alterations in these genes may be limited to lymphoid malignancies, it has been reported that their inactivation by aberrant methylation of 5′ CpG islands may be involved in various hematologic malignancies. In this study, we investigated the p15INK4B and p16INK4A genes to clarify their roles in the pathogenesis of myelodysplastic syndrome (MDS). Southern blotting analysis showed no gross genetic alterations in either of these genes. However, hypermethylation of the 5′ CpG island of the p15INK4B gene occurred frequently in patients with MDS (16/32 [50%]). Interestingly, the p15INK4B gene was frequently methylated in patients with high-risk MDS (refractory anemia with excess blasts [RAEB] , RAEB in transformation [RAEB-t], and overt leukemia evolved from MDS; 14/18 [78%] ) compared with patients with low-risk MDS (refractory anemia [RA] and refractory anemia with ring sideroblast [RARS] ; 1/12 [8%]). Furthermore, methylation status of the p15INK4B gene was progressed with the development of MDS in most patients examined. In contrast, none of the MDS patients showed apparent hypermethylation of the p16INK4A gene. These results suggest that hypermethylation of the p15INK4B gene is involved in the pathogenesis of MDS and is one of the important late events during the development of MDS.

Abstract: The efficiency of upfront consolidation with high‐dose chemotherapy/autologous stem‐cell transplantation (HDCT/ASCT) for newly diagnosed high‐risk diffuse large B‐cell lymphoma (DLBCL) may be influenced by induction chemotherapy. To select better induction chemotherapy regimens for HDCT/ASCT, a randomized phase II study was conducted in high‐risk DLBCL patients having an age‐adjusted International Prognostic Index (aaIPI) score of 2 or 3. As induction chemotherapy, 6 cycles of R‐CHOP‐14 (arm A) or 3 cycles of R‐CHOP‐14 followed by 3 cycles of CHASER (arm B) were planned, and patients who responded proceeded to HDCT with LEED and ASCT. The primary endpoint was 2‐y progression‐free survival (PFS), and the main secondary endpoints included overall survival, overall response rate, and adverse events (AEs). In total, 71 patients were enrolled. With a median follow‐up of 40.3 mo, 2‐y PFS in arms A and B were 68.6% (95% confidence interval [CI], 50.5%‐81.2%) and 66.7% (95% CI: 48.8%‐79.5%), respectively. Overall survival at 2 y in arms A and B was 74.3% (95% CI: 56.4%‐85.7%) and 83.3% (95% CI: 66.6%‐92.1%). Overall response rates were 82.9% in arm A and 69.4% in arm B. During induction chemotherapy, 45.7% and 75.0% of patients in arms A and B, respectively, had grade ≥ 3 non‐hematologic toxicities. One patient in arm A and 6 in arm B discontinued induction chemotherapy due to AEs. In conclusion, R‐CHOP‐14 showed higher 2‐y PFS and less toxicity compared with R‐CHOP‐14/CHASER in patients with high‐risk DLBCL, suggesting the former to be a more promising induction regimen for further investigations (UMIN‐CTR, UMIN000003823).

Abstract: Rituximab plus cyclophosphamide-doxorubicin-vincristine-prednisone (R-CHOP) is the standard of care for untreated diffuse large B-cell lymphoma (DLBCL). However, the schedule for rituximab administration has not been optimized. To compare standard R-CHOP with CHOP plus dose-dense weekly rituximab (RW-CHOP) in patients with untreated DLBCL, we conducted a phase 2/3 study (JCOG0601, jRCTs031180139). Patients were randomly assigned to R-CHOP (CHOP-21 with 8 doses of rituximab once every 3 weeks [375 mg/m2]) or RW-CHOP (CHOP-21 with 8 doses of weekly rituximab [375 mg/m2] ) groups. The primary end point of the phase 2 component was percent complete response (%CR) of the RW-CHOP arm, whereas that of the phase 3 component was progression-free survival (PFS). Between December 2007 and December 2014, 421 untreated patients were randomly assigned to R-CHOP (213 patients) or RW-CHOP (208 patients). The %CR in the RW-CHOP arm was 85.3% and therefore met the prespecified decision criteria for the phase 2 component. With a median follow-up of 63.4 months, the 3-year PFS and overall survival were 79.2% and 88.7% in the R-CHOP arm and 80.3% and 90.4% in the RW-CHOP arm, respectively. There was no significant difference in PFS (hazard ratio, 0.95; 90.6% confidence interval, 0.68-1.31). Although the safety profile and efficacy of RW-CHOP was comparable with R-CHOP and its tolerability was acceptable, weekly rituximab in combination with CHOP during the early treatment period did not improve PFS in untreated patients with DLBCL. This trial was registered at jrct.niph.go.jp as #jRCTs031180139.

Abstract: Background: CHOP plus rituximab (R-CHOP) is the standard of care for previously untreated DLBCL. R-CHOP comprises CHOP and one-dose rituximab in each 21-day cycle; however, the schedule of rituximab administration has not been fully optimized. Dose-dense rituximab was expected to increase its peak concentration to enhance the synergistic effect with chemotherapy at early phase of treatment. To compare weekly administration of rituximab combined with CHOP (RW-CHOP) with standard R-CHOP in patients with previously untreated DLBCL, we conducted a multicenter, randomized phase II/III study (JCOG0601, UMIN000000929). Methods: Previously untreated patients with CD20+ DLBCL were eligible. Other major inclusion criteria were as follows: aged 20-79 years; ECOG performance status 0-2, at least 1 measurable lesion and preserved organ functions. At the beginning of the study, patients with advanced stage disease and the low or low-intermediate risk group by the International Prognostic Index (IPI) were eligible. These criteria were amended in September 2010 to allow enrollment of the patients with any IPI risk and any clinical stage because of slow accrual. Patients were randomly assigned to standard R-CHOP (rituximab 375 mg/m2, cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, vincristine 1.4 mg/m2 [max 2 mg], all IV on day 1, and prednisone 100 mg/day PO [40mg/m2 for aged 〉 65] on days 1-5, every 3 weeks) or RW-CHOP (standard CHOP with eight doses of weekly rituximab [375mg/m2 IV on days1, 8, 15, 22, 29, 36, 43 and 50] ). Six cycles of CHOP were given in stage I non-bulky patients, 8 cycles were given in stage I bulky and II-IV patients, and rituximab was given 8 times regardless of cycles of CHOP. Randomization was stratified by institution, presence or absence of bulky mass and patient age. The primary endpoint of phase III part was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and adverse events (AE). Assuming 3-year PFS in the R-CHOP arm to be 77% and expecting a 7% increase in 3-year PFS of the RW-CHOP arm, required sample size was 211 per arm with a one-sided alpha of 5%, power of 80%, an accrual period of 7 years, and a follow-up period of 3 years. Results: Between December 2007 and December 2014, a total of 422 patients were randomized to study treatments but primary analysis was performed in 421 patients: 213 to the R-CHOP arm and 208 to the RW-CHOP arm, because of one consent withdrawal. Baseline characteristics of 421 eligible patients were as follows (R-CHOP vs. RW-CHOP): median age, 61 vs. 62 years; male sex, 54.5% vs. 55.8%; Ann Arbor stage I/II/III/IV, 14.6/32.9/26.8/25.8% vs. 16.3/42.8/20.2/20.7%; and IPI score ≤2, 77.0% vs. 87.5%. With a median follow-up of 63.4 months (range: 3.2-119.2) among all patients, there was no significant difference in PFS between the arms (hazard ratio [HR], 0.95; 90.6% confidence interval [CI] , 0.68 to 1.31; one-sided log-rank P = 0.39). The 3-year PFS and OS were 79.2% and 88.7% with the R-CHOP arm and 80.3% and 90.4% with the RW-CHOP arm, respectively. The complete response rate and overall response rate were 77.0% and 93.0% in the R-CHOP arm and 82.2% and 91.8% in the RW-CHOP arm, respectively. Major AEs were hematological toxicities and infections. Grade (G) 3/4 neutropenia and G 3/4 thrombocytopenia were observed in 97.7% and 8.0% in the R-CHOP arm and 97.1% and 5.3% in the RW-CHOP arm, respectively. G3 febrile neutropenia was occurred in 33.8% in the R-CHOP arm and in 22.1% in the RW-CHOP arm. The frequency of severe AE was 2.3% in the R-CHOP arm and 3.8% in the RW-CHOP arm. Safety profile was comparable. No unexpected AEs were experienced. Conclusion: In combination of standard CHOP and rituximab, dose-dense weekly rituximab at early phase of treatment did not improve the PFS in patients with untreated DLBCL. Figure. Figure. Disclosures Ohmachi: Celgene: Honoraria; Takeda Pharmaceutical Co., Ltd,: Honoraria; Pfizer: Honoraria; Chugai Pharma: Honoraria; Kyowa Hakko Kirin: Honoraria; Eisai: Honoraria; Janssen: Honoraria; Meiji Pharma: Honoraria. Kinoshita:Takeda: Honoraria; Takeda: Research Funding; Ono: Research Funding; MSD: Research Funding; Solasia: Research Funding; Janssen: Honoraria; Ono: Honoraria; Zenyaku: Research Funding; Eisai: Research Funding; Gilead: Research Funding. Tobinai:Kyowa Hakko Kirin: Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; HUYA Bioscience International: Consultancy, Honoraria; SERVIER: Research Funding; Abbvie: Research Funding. Fukuhara:Sumitomo Dainippon: Research Funding; Solasia: Research Funding; Symbio: Research Funding; Sanofi: Research Funding; Pfizer: Research Funding; Otsuka Pharmaceutical: Research Funding; Ono: Honoraria, Research Funding; Novartis pharma: Research Funding; Nippon-shinyaku: Research Funding; MSD: Research Funding; Mundipharma: Honoraria, Research Funding; Mitsubishi Tanabe: Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Japan Blood Products Organization: Research Funding; Janssen: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Eisai: Honoraria, Research Funding; Boehringer Ingelheim: Research Funding; Daiichi-Sankyo: Research Funding; Chugai: Research Funding; Celgene: Research Funding; Baxalta: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Bayer Yakuhin: Research Funding; Alexionpharma: Research Funding; AbbVie: Research Funding; Astellas: Research Funding; Nihon Ultmarc: Research Funding; Taiho: Research Funding; Teijin Pharma: Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; Takeda: Honoraria. Uchida:Takeda Pharmaceutical: Honoraria; Chugai Pharmaceutical: Honoraria; Kyowa Hakko Kirin: Honoraria; Meiji Seika Pharma: Honoraria; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Nippon Shinyaku: Honoraria; Novartis: Honoraria; Teijin: Honoraria; Celgene: Honoraria; Mundipharma: Honoraria; Janssen Pharma: Honoraria; Otsuka Pharmaceutical: Honoraria; Eisai: Honoraria. Yamamoto:Solasia Pharma: Research Funding; Bristol-Myers Squibb: Honoraria; Novartis: Honoraria, Research Funding; ARIAD Pharmaceuticals: Research Funding; Bayer: Research Funding; Celgene: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Ono: Consultancy, Honoraria, Research Funding; AbbVie: Research Funding; Boehringer Ingelheim: Consultancy; Chugai: Consultancy, Honoraria, Research Funding; Meiji Seika Pharma: Consultancy; MSD: Research Funding; Takeda: Honoraria, Research Funding; Zenyaku: Research Funding; Kyowa Hakko Kirin: Honoraria; Otsuka: Honoraria; Pfizer: Honoraria; Sumitomo Dainippon: Honoraria; Mundipharma: Consultancy, Honoraria; HUYA: Honoraria; SymBio: Research Funding; Gilead Sciences: Research Funding. Miyazaki:Kyowa Hakko Kirin,: Honoraria, Research Funding; Celgene: Honoraria; Chugai Pharma,: Honoraria, Research Funding; Sumitomo Group: Research Funding; Nippon Shinyaku: Research Funding; Takeda: Research Funding; Astellas Pharma: Research Funding; Shionogi Pharmaceutical: Research Funding; Daiichi Sankyo: Research Funding; Eisai: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Teijin Pharma: Research Funding; Ono Pharmaceutical: Research Funding; Toyama Chemical Co: Research Funding; Mochida Pharmaceutical Co. Ltd.: Research Funding; Novo Nordisk: Research Funding. Tsukamoto:Kyowa-Kirin: Research Funding; Pfizer: Research Funding; Chugai: Research Funding; Eisai: Research Funding. Iida:Teijin Pharma: Research Funding; Toyama Chemical: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Kyowa-Hakko Kirin: Research Funding; Chugai: Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Astellas: Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Gilead: Research Funding; MSD: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Sanofi: Consultancy. Yoshida:Taiho Pharma: Honoraria; Takeda Pharma: Honoraria; Celegene: Honoraria; Chugai Pharma: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding. Masaki:Ono: Research Funding; Kyowa Hakko Kirin: Research Funding; Phizer: Research Funding; Astellas: Research Funding; Eisai: Research Funding. Yakushijin:Mundipharma Co.,: Research Funding; Chugai Co.,: Research Funding; Kyowa-kirin Co.,: Research Funding; Merch Sharp & Dohme Corp.,,: Research Funding; Daiichi-Sankyo Inc.,: Research Funding; Eisai Co.: Research Funding. Suehiro:Kyowa Hakko Kirin: Research Funding; Ono Pharmaceutical: Research Funding; Chugai Pharmaceutical: Research Funding; Takeda Pharmaceutical: Research Funding. Nosaka:Bristol-Myers Squibb: Honoraria; Ono Pharmaceutical Co.LTD.: Honoraria; Eisai Co. Ltd.,: Honoraria; Kyowa Kirin Pharmaceutical Development, Inc.,: Honoraria; Chugai Pharmaceutical Co.LTD.,: Honoraria; Celgene Co. LTD.,: Honoraria. Dobashi:Celgene Co.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Kyowa Hakko Kirin Co. Ltd.: Research Funding; Astellas Pharma Inc.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Pfizer Inc.: Research Funding; Sysmex Co.: Research Funding. Kuroda:Chugai Pharma: Honoraria, Research Funding. Takamatsu:Taisho Toyama Pharmaceutical: Research Funding; TAIHO Pharmaceutical: Research Funding; Pfizer: Research Funding; Bristol-Myers Squibb: Research Funding; Ono Pharmaceutical: Research Funding; Astellas Pharma: Research Funding; Kyowa Hakko Kirin: Research Funding; Chugai Pharma: Research Funding; Takeda Pharmaceutical: Research Funding; Celgene: Honoraria. Maruyama:Ono Pharmaceutical: Honoraria, Research Funding; Fujifilm: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Asahi Kasei Pharma: Honoraria; AstraZeneca: Research Funding; Solasia Pharma: Research Funding; Pfizer: Research Funding; Nippon Boehringer Ingelheim: Research Funding; Dai-Nippon-Sumitomo: Honoraria; Dai-ichi-Sankyo: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Biomedis International: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; MSD: Honoraria, Research Funding; Novartis: Research Funding; Otsuka: Research Funding; Amgen Astellas BioPharma: Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Abbvie: Research Funding; Astellas Pharma: Research Funding; Mundipharma International: Honoraria, Research Funding. Ando:Eisai: Research Funding; Meiji Seika Pharma: Research Funding; Takeda Pharmaceutical: Research Funding; Kyowa Hakko Kirin: Research Funding; Japan Blood Products Organization: Research Funding. Ishizawa:Eisai: Honoraria; Janssen: Honoraria; Chugai: Honoraria; Celgene: Honoraria; Otsuka: Research Funding; Sanofi: Research Funding; Phizer: Research Funding. Ogura:Celltrion: Consultancy, Research Funding; Mundi Pharma: Consultancy; SymBio: Research Funding; Takeda: Honoraria; Cellgene: Honoraria; MeijiSeika Pharma: Consultancy. Hotta:SymBio: Consultancy; CellSeed Inc.: Membership on an entity's Board of Directors or advisory committees. Tsukasaki:Celgene: Honoraria; Eisai: Research Funding; Chugai Pharma: Honoraria, Research Funding; HUYA: Consultancy, Research Funding; Ono Pharma: Consultancy; Daiich-Sankyo: Consultancy; Mundy Pharma: Honoraria; Kyowa-hakko/Kirin: Honoraria; Seattle Genetics: Research Funding. Nagai:HUYA Bioscience International: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Ono Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; Gilead Sciences Inc.: Honoraria, Research Funding; Bayer Yakuhin Ltd.: Research Funding; Sanofi K. K.: Honoraria; Zenyaku Kogyo Co., Ltd.: Honoraria, Research Funding; Solasia Pharma K.K.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Roche Ltd.: Honoraria; Esai Co., Ltd.: Honoraria, Research Funding; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; SymBio Pharmaceuticals Limited: Research Funding; Janssen Pharmaceutical K.K.: Honoraria, Research Funding; Kyowa Hakko Kirin Co., Ltd.: Honoraria, Research Funding; Mundipharma K.K.: Honoraria, Research Funding; AstraZeneca plc.: Research Funding; Abbvie G. K.: Research Funding.

Abstract: The CDKN2 gene, encoding the cyclin‐dependent kinase‐4 inhibitor p16, is a putative tumour‐suppressor gene because it is frequently altered in many malignant tumours. We analysed the CDKN2 gene in 44 cases of adult T‐cell leukaemia (ATL) by Southern blot analysis, polymerase chain reaction‐mediated single‐strand conformation polymorphism (PCR‐SSCP) analysis, and direct sequencing. Southern blot analysis detected a homozygous deletion of the CDKN2 gene in 5/44 patients (11.4%). Mutational analysis by the PCR‐SSCP method and direct sequencing showed one nonsense mutation at codon 72 (nucleotide 232), and two missense mutations at codon 43 (nucleotide 146) and codon 97 (nucleotide 309, 3/44, 6.8%). Therefore we found changes in the CDKN2 gene, including point mutations, in 18.2% of the patients with ATL. Interestingly, most of these patients had acute type ATL. Our results suggest that the CDKN2 gene is inactivated not only by homozygous deletion but also by point mutation, and these alterations contribute to the aggressiveness of ATL.

Abstract: Previous studies have shown that the cyclin-dependent kinase inhibitor (CDKI) genes p15INK4B and p16INK4A are frequently inactivated by genetic alterations in many malignant tumors and that they are candidate tumor-suppressor genes. Although genetic alterations in these genes may be limited to lymphoid malignancies, it has been reported that their inactivation by aberrant methylation of 5′ CpG islands may be involved in various hematologic malignancies. In this study, we investigated the p15INK4B and p16INK4A genes to clarify their roles in the pathogenesis of myelodysplastic syndrome (MDS). Southern blotting analysis showed no gross genetic alterations in either of these genes. However, hypermethylation of the 5′ CpG island of the p15INK4B gene occurred frequently in patients with MDS (16/32 [50%]). Interestingly, the p15INK4B gene was frequently methylated in patients with high-risk MDS (refractory anemia with excess blasts [RAEB] , RAEB in transformation [RAEB-t], and overt leukemia evolved from MDS; 14/18 [78%] ) compared with patients with low-risk MDS (refractory anemia [RA] and refractory anemia with ring sideroblast [RARS] ; 1/12 [8%]). Furthermore, methylation status of the p15INK4B gene was progressed with the development of MDS in most patients examined. In contrast, none of the MDS patients showed apparent hypermethylation of the p16INK4A gene. These results suggest that hypermethylation of the p15INK4B gene is involved in the pathogenesis of MDS and is one of the important late events during the development of MDS.