Abstract: Background: Alvocidib is a potent cyclin-dependent kinase 9 inhibitor, which has previously been shown to downregulate the B-cell lymphoma-2 family member MCL-1 (myeloid cell leukemia-1) which, in turn, sensitizes tumor cells to apoptotic signals. Alvocidib has been studied globally in relapsed/refractory (R/R) AML in combination with cytarabine/mitoxantrone, as well as in newly diagnosed AML in combination with cytarabine/daunorubicin, and has demonstrated acceptable clinical activity. However, safety and tolerability in Japanese AML pts are unknown. Aims: To evaluate the safety and tolerability of alvocidib administered as ACM or A+7+3. Methods: This multicenter, open-label, uncontrolled phase 1 study (NCT03563560) included 2 regimens: ACM (in pts R/R to cytarabine/anthracycline based intensive chemotherapy and without a cumulative total exposure of anthracycline [daunorubicin-equivalent dose] exceeding 360 mg/m2 at entry) and A+7+3 (in newly diagnosed, treatment naive pts). Key eligibility criteria for both regimens were age 20-64 years, Eastern Cooperative Oncology Group performance status ≤ 2, a left ventricular ejection fraction ≥ 50%, and no major organ dysfunction. The ACM regimen (cohorts R1 and R2) comprised a fixed dose hybrid regimen of alvocidib (30 mg/m2/day as a 30-minute intravenous [IV] bolus followed by 60 mg/m2/day over 4 hours as a continuous IV infusion on days 1-3), and escalating doses of cytarabine (300 or 667 mg/m2/day by continuous IV infusion on days 6-8) and mitoxantrone (14 or 40 mg/m2/day IV infusion on day 9 or 10 starting 12 hours after completing cytarabine) in a standard 3+3 design. In the A+7+3 regimen (cohort F1) the dose of each component was fixed according to the recommended dose from the ongoing phase 1 study in the US (NCT03298984). Treatment consisted of the alvocidib hybrid regimen on days 1-3, cytarabine 100 mg/m2/day by continuous IV infusion on days 5-11, and daunorubicin 60 mg/m2/day IV on days 5-7. The primary study objective was to determine the safety and tolerability of alvocidib in combination with each type of chemotherapy, via the assessment of dose-limiting toxicities (DLTs) and treatment-emergent adverse events (TEAEs; graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events v4.03). Secondary objectives were to evaluate the pharmacokinetics (including maximum plasma concentration [Cmax] and area under the concentration-time curve up to the last measurable concentration [AUC0-last] ) and clinical activities of these regimens. Results: Between April 2018 to October 2019, 10 pts were enrolled, with a median (range) age of 45.0 (25-64) years. Of these, 6 pts (2 with relapsed disease and 4 with refractory disease) received ACM and 4 pts received A+7+3 (Table). Alvocidib was tolerated and DLTs were not observed in either of the two regimens. The most common TEAEs were hematologic events. The most common Grade ≥ 3 non-hematologic TEAEs occurring in ≥ 2 pts in the ACM regimen were diarrhea (50%), hepatic function abnormal (33%), sepsis (33%), cardiac failure (33%) and hypokalemia (33%). The most common Grade ≥ 3 non-hematologic TEAEs noted in ≥ 2 pts in the A+7+3 regimen were diarrhea (100%), tumor lysis syndrome (50%), and vomiting (50%). In the ACM regimen in R/R AML, all 6 pts were evaluable, of whom 5 (83%) achieved an objective response, including 4 complete remissions (CRs) and 1 morphologic leukemia-free state. The mean duration of CR was 13.6 months. In the A+7+3 regimen in newly diagnosed AML, 3 out of 4 pts were evaluable. All 3 evaluable pts achieved CR. One pt did not complete the A+7+3 regimen due to tumor lysis syndrome and was discontinued from the study prior to disease assessment. Overall, the mean Cmax of alvocidib in plasma was 1241 ng/mL on day 1 and 1217 ng/mL on day 3. The mean AUC0-last was 6555 h*ng/mL on day 1 and 7998 h*ng/mL on day 3. WSummary: Alvocidib in combination with cytarabine 667 mg/m2/day and mitoxantrone 40 mg/m2/day IV infusion in Japanese pts with R/R AML or cytarabine/daunorubicin (7+3) induction in Japanese pts with newly diagnosed AML showed an acceptable safety profile similar to previously investigated regimens in other studies. These data suggest that future studies of alvocidib in hematological malignancies are warranted, and planned directions for alvocidib development include phase 1/2 efficacy and safety studies in combination with other agents. Disclosures Ando: Sumitomo Dainippon Pharma Co., Ltd.: Research Funding. Kiguchi:SymBio Pharmaceuticals., Ltd.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Honoraria, Research Funding; Daiichi Sankyo Pharmaceutical Co., Ltd.: Research Funding; Eisai Co., Ltd.: Honoraria; Mochida Pharmaceutical Co., Ltd.: Honoraria; Taiho Pharmaceutical Co., Ltd.: Research Funding; Teijin Co., Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria; Pfizer Co., Ltd.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Novartis Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Sumitomo Dainippon Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Janssen Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Celgene Co., Ltd.: Honoraria, Research Funding; Celltrion, Inc.: Research Funding; Bristol-Myers Squibb Co., Ltd.: Honoraria, Research Funding; MSD Co., Ltd.: Honoraria, Research Funding; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Ono Pharmaceutical Co., Ltd.: Honoraria; Sanofi K.K., Ltd.: Research Funding; Nippon Shinyaku Co., Ltd.: Honoraria, Research Funding; Astellas Pharmaceutical Co., Ltd.: Honoraria, Research Funding. Kasai:Sumitomo Dainippon Pharma Co., Ltd.: Current Employment. Sugimoto:Sumitomo Dainippon Pharma Co., Ltd.: Current Employment. Miyazaki:NIPPON SHINYAKU CO.,LTD.: Honoraria; Otsuka Pharmaceutical: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria; Novartis Pharma KK: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; Astellas Pharma Inc.: Honoraria; Celgene: Honoraria.

Abstract: Mycobacterium smegmatis DSM43756 inactivates rifampin, and the inactivated antibiotic product recovered from culture medium was ribosylated on the 23-OH group. To study this process, the gene responsible for the inactivation was expressed at high levels by the lac promoter in Escherichia coli conferring resistance to 〉 500 μg of antibiotic per ml. Cell homogenates generated a novel derivative designated RIP-TAs; in this study, we determined that RIP-TAs is 23-( O -ADP-ribosyl)rifampin. Our results indicated that RIP-TAs is an intermediate in the pathway leading to ribosylated rifampin and that the previously characterized gene encodes a mono(ADP-ribosyl)transferase which, however, shows no sequence similarity to other enzymes of this class.

Abstract: Introduction The prognosis of classic Hodgkin lymphoma (cHL) in young adults has improved following advances in current therapeutics. However, evidence of elderly patients with cHL has limited due to its rarer. To analyze clinical outcomes and risk factors in elderly patients with advanced-stage cHL who received a doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) regimen, we conducted a nationwide multi-center retrospective study in Japan (UMIN000033264). Methods The key eligibility criteria of the current study were as follows: 1) patients with histologically diagnosed cHL between 2007 and 2016 in each institution; 2) advanced-stage cHL (stage III, IV or IIB with bulky or extranodal lesion); 3) age at diagnosis & gt; 60 years; and 4) had received at least one cycle of an ABVD regimen as initial treatment including a modified ABVD regimen (dacarbazine dose reduced to 250 mg/m 2 at first cycle). Patients with human immunodeficiency virus infection or methotrexate-associated cHL were excluded. The primary endpoint was 5-year overall survival (OS). Secondary endpoints included progression-free survival (PFS) and event-free survival (EFS), the latter defined as the time from a diagnosis of cHL to disease progression or relapse, subsequent systemic chemotherapy for cHL, or death due to any cause in this study. The average relative dose intensity (ARDI) of ABVD was calculated as the sum of the relative dose intensity of each drug divided by four. Results A total of 171 patients from 45 institutions were included in this study. The central pathological review could be performed in 140 cases (82%), in which histological subtypes of cHL were determined as follows: mixed cellularity, 89 (64%); nodular sclerosis, 33 (24%); lymphocyte-deleted, 4 (3%); lymphocyte-rich, 2 (1%); not otherwise specified, 12 (9%). The median age was 71 years (interquartile range [IQR] 65-76). The number of patients in each 10-year age group was 79 (46%) for 61-70 years, 78 (46%) for 71-80 years, and 14 (8%) for & gt; 81 years. The numbers of patients with ECOG performance status (PS) ≥2 and B symptoms were 33 (19%) and 85 (50%), respectively. Bulky mediastinal diseases were found in four patients (2%). The risk factors used for the International Prognostic Score (IPS), including male sex, stage IV, hypoalbuminemia, anemia, leukocytosis, and lymphopenia, were not significantly different among these age groups. The median number of cycles of ABVD was 6 (IQR:5-7), and 66% of patients completed at least 6 cycles. The median ARDI was 77%. The median ARDI in each 10-year age group was 88% for 61-70 years, 71% for 71-80 years, and 54% for & gt; 81 years. With a median follow-up time of 52 months (IQR:31-76), the estimated OS, PFS, and EFS at 5 years were 72%, 59%, and 54%, respectively. Among 131 patients whose Epstein-Barr virus (EBV) status was analyzed using EBV-encoded small RNA1 (EBER1) in situ hybridization, 61 (46%) were positive for EBER1. The OS was not significantly different between EBV-positive and EBV-negative patients (75% and 76% at 5 years, respectively). Univariate analysis for OS revealed that age, PS ≥ 2, hypoalbuminemia, anemia, lymphopenia, and the presence of B symptoms were significantly associated with short OS. In multivariate analysis, age (hazard ratio [HR] 1.568 per 10-year increase, 95% confidence interval [CI] 1.020-2.411) was only an independent risk factor for OS, whereas lymphopenia (HR 1.967, 95% CI 1.196-3.235) was an independent risk factor for EFS. Higher ARDI was significantly associated with improved OS and EFS. Bleomycin-induced lung toxicity (BLT), observed in 41 (24%) patients, was not associated with OS. In this study, we found that 55 patients died: 23 within two years after diagnosis mainly due to cHL progression (n = 10, 43%) and treatment-related toxicity (infection [n = 4, 17%] and BLT [n = 4, 17%] ). The remaining 32 patients died more than two years after diagnosis mainly due to second primary malignancies (n = 14, 44%), including solid tumors (n = 6), other types of lymphoma (n = 4), and myelodysplastic syndrome/acute myeloid leukemias (n = 4). Conclusions The HORIZON study showed relatively good prognosis for elderly patients with advanced-stage cHL who received an ABVD regimen (estimated five-year OS rates was 72%). Age and lymphopenia were an independent risk factors for OS and EFS, respectively. The development of novel therapies is warranted to improve the outcomes of such patients. Disclosures Makita: SymBio: Honoraria; Novartis: Honoraria; Eisai: Honoraria; Daiichi-Sankyo: Consultancy; CSL Behring: Honoraria; Chugai: Honoraria; BMS: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Kusumoto: Kyowa Kirin: Honoraria; Chugai: Honoraria, Research Funding; Daiichi Sankyo: Research Funding. Tsujimura: Takeda: Honoraria; Chugai: Honoraria; Kyowa Kirin: Honoraria; Eisai: Honoraria; Janssen: Honoraria. Takayama: Chugai: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding. Kuroda: Otsuka Pharmaceutical: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; MSD: Research Funding; Abbvie: Consultancy, Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Sysmex: Research Funding; Pfizer: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Shionogi: Research Funding; Asahi Kasei: Research Funding; Taiho Pharmaceutical: Research Funding; Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Shimada: BMS: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Janssen: Honoraria; Chugai: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; AstraZeneca: Honoraria; Otsuka: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; SymBio: Honoraria. Okamoto: Chugai: Research Funding; Kyowa Kirin: Research Funding; Ono: Research Funding; Taiho: Research Funding; Takeda: Research Funding. Asano: Takeda: Honoraria. Maruyama: Janssen: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Novartis: Research Funding; MSD: Honoraria, Research Funding; Otsuka: Research Funding; Ono: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Astellas Pharma,: Research Funding; Celgene: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Amgen: Research Funding; BMS: Honoraria, Research Funding; Mundipharma: Honoraria; Kyowa Kirin: Honoraria; Zenyaku: Honoraria; AstraZeneca: Honoraria; Nippon: Honoraria; SymBio: Honoraria. Yamaguchi: Chugai: Honoraria, Research Funding; Genmab: Research Funding; MSD: Honoraria; Kyowa Kirin: Honoraria, Research Funding; Takeda: Honoraria; Ono: Honoraria; Celgene: Honoraria; Otsuka: Honoraria; Sumitomo Dainippon: Honoraria; Eisai: Honoraria; AstraZeneca: Consultancy. Nagai: AbbVie: Research Funding; AstraZeneca: Honoraria, Research Funding; Bayer: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Chordia Therapeutics: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Kyowa Kirin: Research Funding; Mundipharma: Honoraria, Research Funding; Nippon Shinyaku: Research Funding; Novartis: Honoraria; Ono Pharmaceutical: Honoraria; Sanofi: Honoraria; Sumitomo Dainippon Pharma: Honoraria; SymBio Pharmaceuticals: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Zenyaku Kogyo: Research Funding.