- Email: [email protected]
312 A phase I dose escalation study to assess the safety tolerability and pharmacokinetics of ETS2101 in patients (pts) with advanced solid tumours
S58 level in serum is significantly lower than that in peritoneal exudate in two groups. Compared with the controls, the quantity of malignant ascites in mice in the 5-Fu targeted carrier erythrocyte i. p. group has significant regression, and the survival time is prolonged. The reasons may be lie in 5-Fu targeted carrier erythrocyte can induce the increased apoptosis of tumor cells. No conflict of interest. 310 POSTER The evaluation of anti-cancer activity of three novel carbocyclic pyrrolo[2,3-d]pyrimidine analogs in human prostate cancer LNCaP cells H. Suh1 , K.W. Choi1 , H. Rhee2 , O.N. Bae1 , C.H. Lee1 . 1 Hanyang University, Pharmacy, Ansan, Korea; 2 Hanyang University, Bionanotechnology and Applied Chemistry, Ansan, Korea Background: Prostate cancer is one of the most frequent type of cancer and a leading cause of cancer death in males in the world. Because dysregulation of androgen signaling is primary reason of disease, androgen deprivation is main-therapeutic approach to treat prostate cancer. In the course of our screening for cell cycle inhibitor, we found a novel carbocyclic pyrrolo-pyrimidine compound, MCS-C3, 4-amino-6-bromo-1cyclopentyl-1H-pyrrolo[2,3-d]pyrimidine-5-carboxamide. We confirmed that MCS-C3 induced apoptotic cell death in human prostate cancer LNCaP cells. To figure out the Structure-Activity Relationship (SAR) of MCSC3, other carbocyclic nucleoside analogs, MCS-C3a and MCS-C3b were synthesized with structural modification; MCS-C3a has nitrile group on the position of amide group on cyclopentyl ring, and MCS-C3b has been derived by the deletion of amide group. In this study, the anti-cancer activity of three novel compounds, MCS-C3, MCS-C3a and MCS-C3b was evaluated in human prostate cancer LNCaP cells. Material and Methods: We tested the newly synthesized MCS-C3, MCSC3a and MCS-C3b in Androgen Receptor (AR)-positive human prostate cancer LNCaP cells to evaluate anti-proliferative activity and apoptosis induction by MTT assay and Western blotting. Flow cytometric analysis with Propidium Iodide staining was performed to check the effect on cell cycle progression. Results: As results, MCS-C3 and MCS-C3a had an effect on G2 phase cell cycle arrest and apoptotic induction in LNCaP cells. A flow cytometric analysis of LNCaP cells revealed appreciable increasing of apoptotic population following treatment with MCS-C3 and MCS-3a, so we found that MCS-C3a resulted in much better anti-proliferative effect than MCSC3. This apoptotic induction is associated with the activation of caspases and the cleavage of poly(ADP-ribose) polymerase (PARP). But, MCS-C3b had no effect on cell viability, despite it decreased the androgen receptor activity levels in a dose-dependent manner. Conclusions: These data suggest that MCS-C3 or MCS-C3a, but not MCS-C3b, is possible candidate for anti-cancer agent inducing apoptosis via caspase-dependent pathway. According to the biological activity data, the existence of amide functional group and the hydrophobic character would play important roles in the anti-cancer activity of the novel carbocyclic pyrrolo[2,3-d]pyrimidine analogs. No conflict of interest. 311 POSTER Isothiourea derivatives and CK2 inhibitors − a potential proapoptotic and cytostatic agents against astroglial tumours in vitro E.B. Pucko1 , M. Koronkiewicz2 , Z. Kazimierczuk3 , R.P. Ostrowski4 , K. Ste˛pien´ 4 , E. Matyja4 . 1 Mossakowski Medical Research Centre Polish Academy of Sciences, Department of Experimental and Clinical Neuropathology, Warsaw, Poland; 2 National Medicines Institute, Department of Cell Biology, Warsaw, Poland; 3 Warsaw University of Life Sciences, Department of Chemistry, Warsaw, Poland; 4 Mossakowski Medical Research Centre, Polish Academy of Sciences, Department of Experimental and Clinical Neuropathology, Warsaw, Poland Background: Gliomas are the most common primary brain tumours characterized by infiltrative cell growth and tendency to malignant transformation. Current therapies, including surgery, radio- and chemotherapy remain incurable and the median survival of patients with malignant gliomas is still no longer than 12 months. Considering the therapeutic chemicals with potential anticancer activity, two group of agents seem to be worth of testing: casein kinase (CK2) inhibitors and isothioureas derivatives. The CK2 is expressed at high levels in many human cancers and promotes cell survival through oncogene regulation and anti-apoptotic properties.
Abstracts The CK2 inhibitors can therefore show antitumour effect. Isothioureas derivatives seem to be also a compounds with potential anticancer efficacy. In this study we examined the cytotoxic and proapoptotic effects of selected new isothiourea derivatives − pentabromobenzylisothioureas (ZKKs) and CK2 inhibitors against cell lines of glial origin. Materials and Methods: The study was performed on human glioblastoma cell line (T98G) and cell lines derived from a rare, low-grade pediatric brain tumour of mixed glioneuronal lineage − subependymal giant cell astrocytoma (SEGA). The tested compounds included: ZKK-2, ZKK-3, TRIM and selected CK2 inhibitors. We evaluated cell viability (MTT metabolism assay), proliferation (Multisizer3 Beckman Coulter) and apoptosis (flow cytometry technique). Results: CK2 inhibitors and pentabromobenzylisothioureas induced the decrease of a total cells number of T98G and SEGA after 24 and 48 hours of treatment. ZKK-2, ZKK-3 and TRIM displayed the most potent inhibitor activity, even at a very low concentration of 1mM. They caused a statistically significant decrease of T98G cells viability. ZKK-3 and TRIM appeared to be the most potent proapoptotic agent. Among CK2 inhibitors, TBIAEA effectively reduced the viability of glimas cell lines. Conclusions: Our experiments in vitro documented that selected CK2 inhibitors and new pentabromobenzylisothioureas (ZKKs) exhibit a potent antiproliferative and proapoptotic efficacy against glioma cells. It may offer a promising anticancer therapy, including the treatment of glioma-derived primary brain tumours. Acknowledgement: The research was supported by the Foundation for the Development of Diagnostic and Therapy. No conflict of interest. 312 POSTER A phase I dose escalation study to assess the safety tolerability and pharmacokinetics of ETS2101 in patients (pts) with advanced solid tumours R. Plummer1 , A. Anthoney2 , J. Evans3 , N. Haris1 , M. D’Archangelo1 , S. Slater3 , S. Campbell3 , C. Brindley4 , S. Self5 , P. McKeown5 , S. Lavin5 , D. Hynes5 , M.V. Flores5 , A. Pedret-Dunn5 , B. Laffranchi6 . 1 Northern Institute for Cancer Research, University of Newcastle-upon-Tyne, Medical Oncology, Newcastle-upon-Tyne, United Kingdom; 2 Leeds Institute of Molecular Medicine and St James’s Institute of Oncology, Medical Oncology, Leeds, United Kingdom; 3 Beatson West of Scotland Cancer Centre, University of Glasgow, Medical Oncology, Glasgow, United Kingdom; 4 KinetAssist, Pharmacokinetics, Lanarkshire, United Kingdom; 5 e-Therapeutics plc, Development, Oxfordshire, United Kingdom; 6 Consultant, Clinical Oncology, Nice, France Background: ETS2101 is a synthetic cannabinoid with limited affinity to cannabinoid receptors 1 and 2, reducing its psychotropic potential in comparison to other cannabinoids. We report a phase I study of ETS2101– 001, exploring safety, tolerability and PK of ETS2101 in pts with advanced solid tumours. Material and Methods: Pts with advanced cancer, for whom there was no standard therapy, were enrolled in 3+3 pt cohorts at 3 centres in the UK. Dose escalation of ETS2101 was permitted in the absence of any doselimiting toxicities (DLTs) in n = 3 pts or 1 DLT in n = 6 pts. The primary objective was to establish the maximum tolerated dose (MTD) of ETS2101 as single agent in pts with advanced solid tumours. Results: At the time of data cut-off (17Apr15), recruitment was complete and 40 pts had received at least one dose of ETS2101, administered via a 3 h i.v. infusion once-weekly. Of these, 36 pts had either completed cycle (cy) 1 (3 weeks) of dosing, or were withdrawn during cy 1 due to DLTs. Eight dose levels were investigated: 2 mg/kg (n = 3), 3 mg/kg (n = 3), 6 mg/kg (n = 3), 12 mg/kg (n = 7), 15 mg/kg (n = 3), 22 mg/kg (n = 3), 30 mg/kg (n = 9), 36 mg/kg (n = 3). An additional 6 pts were recruited and dosed at the MTD (30 mg/kg). The 2 adverse events (AEs) deemed causally related and dose-limiting at the non-tolerated dose of 36 mg/mg were both Grade (G) 3 somnolence. At the MTD, the most common related-AEs were feelings of intoxication, tremor, diarrhoea, nausea and somnolence (all G1/2). Two pts dosed at the MTD experienced hypersensitivity reactions which were both attributed to the drug vehicle (Cremophor® EL), despite the administration of standard prophylactic medications. PK data at the MTD showed that geometric mean Cmax values of 28 and 32 mg/mL of ETS2101 were reached at 3 h post-dose following administration on days (D) 1 and 8, respectively. Exposures of 100 and 103 mg.h/mL were achieved on D1 and 8 respectively. Pt disease was assessed using RECIST v1.1 and 36 pts were evaluable for response. One pt achieved PR (oesophageal Ca). At the time of cut-off, of pts who had discontinued study drug, 5 showed SD after 4 cy (12 weeks) with one patient (pancreatic Ca) showing a TTP of 14 cy (42 weeks). The mean TTP was 11 weeks.
Abstracts Conclusions: ETS2101 was generally safe and well tolerated in pts with solid tumours up to the MTD of 30 mg/kg i.v. once weekly, while 2/3 pts had a DLT at 36 mg/kg. Systemic exposure increased greater than dose proportionately up to the MTD of 30 mg/kg (for a dose doubling, systemic exposure was predicted to increase 2.5 to 2.6-fold). One PR (oesophageal Ca) and a notable stable disease (pancreatic Ca with a TTP of 42 weeks) have been reported. Further studies are being initiated. Conflict of interest: Ownership: S. Self owns stock in e-Therapeutics plc. D. Hynes owns stock in e-Therapeutics plc. M. V. Flores owns stock in e-Therapeutics plc. Board of Directors: S. Self is on the Board of Directors at e-Therapeutics plc. Other Substantive Relationships: S. Self, P. McKeown, S. Lavin, D. Hynes, A Pedret-Dunn and M. V. Flores are employees of e-Therapeutics plc and have future share options in e-Therapeutics plc. B. Laffranchi provides contractor services for e-Therapeutics plc. 313 POSTER Molecular mode of action of NKP-1339 − a clinically investigated ruthenium-based drug − involves Nrf2 translocation and ER-associated protein degradation in colon carcinoma cell lines L.S. Flocke1 , R. Trondl2 , L. Bamonti3 , M.A. Jakupec2 , B.K. Keppler2 . 1 Inorganic Chemistry, Chemistry, Vienna, Austria; 2 Inorganic Chemistry and Research Platform “Translational Cancer Therapy Research”, Chemistry, Vienna, Austria; 3 Analytical Chemistry, Chemistry, Vienna, Austria Background: NKP-1339 is a clinically investigated ruthenium compound, which shows promising results in solid tumors, such as non-small cell lung cancer, colorectal carcinoma, and most distinctive in gastrointestinal neuroendocrine tumors (Thompson et al., 2012). The ruthenium-indazole complex has been shown to bind albumin and transferrin within a few minutes (Bytzek et al., 2011), which could also lead to accumulation in tumor tissue via the enhanced permeability and retention (EPR) effect. Recent studies imply the ability to induce apoptosis via targeting GRP78. Material and Methods: ROS assay: Cells were stained with DCFHDA and exposed to different concentrations of NKP1339 in media containing different serum concentrations and fluorescence measured with a multimode microplate reader. Cellular uptake: The ruthenium uptake into colon cancer cells was examined for different serum concentrations by ICPMS measurement. Reverse-transcription quantitative polymerase chain reaction: Reversely transcribed cDNA levels were analyzed by EvaGreen® for the following ER stress key factor genes: GRP78, ATF4, IRE1a and CHOP as well as for XBP1 splicing by probes coupled to FAM and TET. Western blotting: Protein levels of GRP78, p-eIF2a, PERK, CHOP and the reference gene b-actin were analyzed by PAGE. Fluorescence microscopy: Cells were cultured on a cover slip, and Nrf2 translocation was investigated by immune fluorescence analysis. Results: Our investigations could show via ICP-MS measurements that NKP1339 uptake is increased in cells treated in media containing less FCS. Likewise it displays activity and induces reactive oxygen species (ROS) in a manner inversely dependent on serum concentration leading to a redox imbalance. Hereby it could be shown that the influence of serum proteins is multifaceted and significant. The redox imbalance leads to Nrf2 translocation into the nucleus which is known to induce antioxidant response element (ARE) gene translation. NKP-1339 was also shown to induce imbalance of the ER equilibrium, leading to a decrease of different proteins, e. g. GRP78, via a mechanism called ER-associated protein degradation (ERAD). Even though endoplasmic reticulum (ER) stress key factors were only mildly regulated on the mRNA basis, a significant upregulation of CHOP, p-eIF2a and PERK could be verified on protein level via Western blotting. Conclusion: In this study we revealed additional new underlying aspects of NKP-1339’s molecular mode of action. The role of ROS generation is highly serum-dependent, and ER imbalances support via the unfolded protein response, ER stress and ERAD the apoptotic pathway. Acknowledgment: This work was supported by the Mahlke nee´ Obermann Foundation. No conflict of interest.
S59 314 POSTER Phase 1 study of abemaciclib, a CDK 4 and 6 inhibitor, as a single agent for Japanese patients with advanced cancer S. Kondo1 , N. Yamamoto1 , K. Tamura1,2 , Y. Tanabe1,2 , S. Iwasa1 , A. Shimomura1 , Y. Shibasaki3 , K. Ogasawara3 , K. Turner-Jones4 , J. Mori3 , H. Asou3 , E. Michael Chan5 , Y. Fujiwara1 . 1 National Cancer Center Hospital, Department of Experimental Therapeutics, Tokyo, Japan; 2 National Cancer Center Hospital, Department of Breast and Medical Oncology, Tokyo, Japan; 3 Eli Lilly Japan K.K., Medicines Development Unit-Japan, Hyogo, Japan; 4 Eli Lilly and Company, Global PK/PD and Pharmacometrics, Indianapolis, USA; 5 Eli Lilly and Company, CDK 4/6 product team, Indianapolis, USA Background: Abemaciclib (LY2835219) is a small molecule inhibitor of cyclin dependent kinases 4 and 6 that has shown single agent clinical activity against multiple human tumors including lung cancer, breast cancer, and mantle cell lymphoma (Shapiro et al, ASCO 2013; Goldman et al, ASCO 2014; Patnaik et al, ASCO 2014; Tolaney et al, SABCS 2014; Morschhauser et al, ASH 2014). This study (NCT02014129) evaluated safety, pharmacokinetics (PK) and antitumor activity of abemaciclib in Japanese patients (pts) with advanced cancer up to maximum tolerated dose (MTD) as established in the previous phase 1 study (NCT01394016). Methods: Pts received abemaciclib at one of 3 dose levels (100, 150 or 200 mg) orally every 12 hours (Q12H) until disease progression or meeting any discontinuation criteria. Dose escalation was designed to proceed in cohorts of 3 or 6 pts until either 33% of pts in one cohort experienced dose-limiting toxicity (DLT) or the planned highest dose level was reached. Eligibility included ECOG performance status 1 and advanced cancer for which prior standard therapies had failed. Safety was assessed by CTCAE v4.03. The PK parameter estimates were computed using standard noncompartmental analysis methods. Antitumor activity was evaluated using RECIST v1.1. Results: A total of 12 Japanese pts started treatment with abemaciclib: 3 at 100 mg, 3 at 150 mg and 6 at 200 mg Q12H. The most common possibly related treatment-emergent adverse events (TEAEs) occurring in 5 pts were diarrhoea (75% for all grades, 8% G3), blood creatinine increased (75%, 0%), white blood cell decreased (42%, 33%), and decreased appetite (42%, 0%). Diarrhoea occurred in all 6 pts treated with 200mg Q12H; however, these events were manageable and no pts discontinued study treatment due to diarrhoea. One pt treated at 200 mg Q12H experienced DLT due to nausea (G2) which required dose omission. No deaths or possibly related G4/5 TEAEs were reported. The PK profile of abemaciclib was characterized by slow absorption (median Tmax ranging from 5 to 6 hours postdose) and mean terminal half-life between 16 and 22 hours. No relationship was detected between QTcF intervals and abemaciclib plasma concentrations. Conclusions: Abemaciclib showed tolerability and acceptable safety as a single agent for Japanese pts with advanced cancer up to MTD (200 mg Q12H). Antitumor activity is under investigation and updated data will be presented at the meeting. Conflict of interest: Ownership: Yuko Shibasaki, Ken Ogasawara and Joji Mori are employees of Eli Lilly Japan K.K. Hiroya Asou was an employee of Eli Lilly Japan K.K. Kellie Turner-Jones and Edward Michael Chan are employees of Eli Lilly and Company. Kellie TurnerJones and Edward Michael Chan have stock ownership of Eli Lilly and Company. Advisory Board: Yutaka Fujiwara is an advisory boad member of Novartis Pharmaceuticals Japan. Corporate-sponsored Research: Noboru Yamamoto received research funding for clinical trials from Chugai Pharmaceutical CO., Ltd, Eli Lilly Japan, TAIHO PHARMA, Eisai Co., Ltd, Quintiles, Astellas, Bristol-Myers Squibb, Novartis Pharmaceuticals Japan, Daiichi-Sankyo, Pfizer, Takeda Pharmaceutical CO., Ltd and Boehringer Ingelheim. Satoru Iwasa received research funding for clinical trials from Eli Lilly Japan. Yutaka Fujiwara received research funding for clinical trials from AstraZeneca and Eli Lilly Japan. 315 POSTER Impact of acid-reducing agents (ARAS) on the pharmacokinetics of palbociclib, a weak base with ph-dependent solubility, under differing food intake conditions W. Sun1 , K.J. Klamerus1 , L.M. Yuhas2 , S. Pawlak3 , A. Plotka4 , M. O’Gorman5 , M. Kosa6 , D. Wang1 . 1 Pfizer Inc, Clinical Pharmacology, San Diego, USA; 2 Pfizer Inc, Pharmaceutical Science, Groton, USA; 3 Pfizer Inc, Pfizer Clinical Research Unit, New Haven, USA; 4 Pfizer Inc, Statistics, Collegeville, USA; 5 Pfizer Inc, Clinical Pharmacology, Groton, USA; 6 Formerly Pfizer Inc, Clinical Pharmacology, San Diego, USA Background: Bioavailability of weakly basic drugs with pH-dependent solubility may be reduced when coadministered with ARAs, potentially
Abstracts The CK2 inhibitors can therefore show antitumour effect. Isothioureas derivatives seem to be also a compounds with potential anticancer efficacy. In this study we examined the cytotoxic and proapoptotic effects of selected new isothiourea derivatives − pentabromobenzylisothioureas (ZKKs) and CK2 inhibitors against cell lines of glial origin. Materials and Methods: The study was performed on human glioblastoma cell line (T98G) and cell lines derived from a rare, low-grade pediatric brain tumour of mixed glioneuronal lineage − subependymal giant cell astrocytoma (SEGA). The tested compounds included: ZKK-2, ZKK-3, TRIM and selected CK2 inhibitors. We evaluated cell viability (MTT metabolism assay), proliferation (Multisizer3 Beckman Coulter) and apoptosis (flow cytometry technique). Results: CK2 inhibitors and pentabromobenzylisothioureas induced the decrease of a total cells number of T98G and SEGA after 24 and 48 hours of treatment. ZKK-2, ZKK-3 and TRIM displayed the most potent inhibitor activity, even at a very low concentration of 1mM. They caused a statistically significant decrease of T98G cells viability. ZKK-3 and TRIM appeared to be the most potent proapoptotic agent. Among CK2 inhibitors, TBIAEA effectively reduced the viability of glimas cell lines. Conclusions: Our experiments in vitro documented that selected CK2 inhibitors and new pentabromobenzylisothioureas (ZKKs) exhibit a potent antiproliferative and proapoptotic efficacy against glioma cells. It may offer a promising anticancer therapy, including the treatment of glioma-derived primary brain tumours. Acknowledgement: The research was supported by the Foundation for the Development of Diagnostic and Therapy. No conflict of interest. 312 POSTER A phase I dose escalation study to assess the safety tolerability and pharmacokinetics of ETS2101 in patients (pts) with advanced solid tumours R. Plummer1 , A. Anthoney2 , J. Evans3 , N. Haris1 , M. D’Archangelo1 , S. Slater3 , S. Campbell3 , C. Brindley4 , S. Self5 , P. McKeown5 , S. Lavin5 , D. Hynes5 , M.V. Flores5 , A. Pedret-Dunn5 , B. Laffranchi6 . 1 Northern Institute for Cancer Research, University of Newcastle-upon-Tyne, Medical Oncology, Newcastle-upon-Tyne, United Kingdom; 2 Leeds Institute of Molecular Medicine and St James’s Institute of Oncology, Medical Oncology, Leeds, United Kingdom; 3 Beatson West of Scotland Cancer Centre, University of Glasgow, Medical Oncology, Glasgow, United Kingdom; 4 KinetAssist, Pharmacokinetics, Lanarkshire, United Kingdom; 5 e-Therapeutics plc, Development, Oxfordshire, United Kingdom; 6 Consultant, Clinical Oncology, Nice, France Background: ETS2101 is a synthetic cannabinoid with limited affinity to cannabinoid receptors 1 and 2, reducing its psychotropic potential in comparison to other cannabinoids. We report a phase I study of ETS2101– 001, exploring safety, tolerability and PK of ETS2101 in pts with advanced solid tumours. Material and Methods: Pts with advanced cancer, for whom there was no standard therapy, were enrolled in 3+3 pt cohorts at 3 centres in the UK. Dose escalation of ETS2101 was permitted in the absence of any doselimiting toxicities (DLTs) in n = 3 pts or 1 DLT in n = 6 pts. The primary objective was to establish the maximum tolerated dose (MTD) of ETS2101 as single agent in pts with advanced solid tumours. Results: At the time of data cut-off (17Apr15), recruitment was complete and 40 pts had received at least one dose of ETS2101, administered via a 3 h i.v. infusion once-weekly. Of these, 36 pts had either completed cycle (cy) 1 (3 weeks) of dosing, or were withdrawn during cy 1 due to DLTs. Eight dose levels were investigated: 2 mg/kg (n = 3), 3 mg/kg (n = 3), 6 mg/kg (n = 3), 12 mg/kg (n = 7), 15 mg/kg (n = 3), 22 mg/kg (n = 3), 30 mg/kg (n = 9), 36 mg/kg (n = 3). An additional 6 pts were recruited and dosed at the MTD (30 mg/kg). The 2 adverse events (AEs) deemed causally related and dose-limiting at the non-tolerated dose of 36 mg/mg were both Grade (G) 3 somnolence. At the MTD, the most common related-AEs were feelings of intoxication, tremor, diarrhoea, nausea and somnolence (all G1/2). Two pts dosed at the MTD experienced hypersensitivity reactions which were both attributed to the drug vehicle (Cremophor® EL), despite the administration of standard prophylactic medications. PK data at the MTD showed that geometric mean Cmax values of 28 and 32 mg/mL of ETS2101 were reached at 3 h post-dose following administration on days (D) 1 and 8, respectively. Exposures of 100 and 103 mg.h/mL were achieved on D1 and 8 respectively. Pt disease was assessed using RECIST v1.1 and 36 pts were evaluable for response. One pt achieved PR (oesophageal Ca). At the time of cut-off, of pts who had discontinued study drug, 5 showed SD after 4 cy (12 weeks) with one patient (pancreatic Ca) showing a TTP of 14 cy (42 weeks). The mean TTP was 11 weeks.
Abstracts Conclusions: ETS2101 was generally safe and well tolerated in pts with solid tumours up to the MTD of 30 mg/kg i.v. once weekly, while 2/3 pts had a DLT at 36 mg/kg. Systemic exposure increased greater than dose proportionately up to the MTD of 30 mg/kg (for a dose doubling, systemic exposure was predicted to increase 2.5 to 2.6-fold). One PR (oesophageal Ca) and a notable stable disease (pancreatic Ca with a TTP of 42 weeks) have been reported. Further studies are being initiated. Conflict of interest: Ownership: S. Self owns stock in e-Therapeutics plc. D. Hynes owns stock in e-Therapeutics plc. M. V. Flores owns stock in e-Therapeutics plc. Board of Directors: S. Self is on the Board of Directors at e-Therapeutics plc. Other Substantive Relationships: S. Self, P. McKeown, S. Lavin, D. Hynes, A Pedret-Dunn and M. V. Flores are employees of e-Therapeutics plc and have future share options in e-Therapeutics plc. B. Laffranchi provides contractor services for e-Therapeutics plc. 313 POSTER Molecular mode of action of NKP-1339 − a clinically investigated ruthenium-based drug − involves Nrf2 translocation and ER-associated protein degradation in colon carcinoma cell lines L.S. Flocke1 , R. Trondl2 , L. Bamonti3 , M.A. Jakupec2 , B.K. Keppler2 . 1 Inorganic Chemistry, Chemistry, Vienna, Austria; 2 Inorganic Chemistry and Research Platform “Translational Cancer Therapy Research”, Chemistry, Vienna, Austria; 3 Analytical Chemistry, Chemistry, Vienna, Austria Background: NKP-1339 is a clinically investigated ruthenium compound, which shows promising results in solid tumors, such as non-small cell lung cancer, colorectal carcinoma, and most distinctive in gastrointestinal neuroendocrine tumors (Thompson et al., 2012). The ruthenium-indazole complex has been shown to bind albumin and transferrin within a few minutes (Bytzek et al., 2011), which could also lead to accumulation in tumor tissue via the enhanced permeability and retention (EPR) effect. Recent studies imply the ability to induce apoptosis via targeting GRP78. Material and Methods: ROS assay: Cells were stained with DCFHDA and exposed to different concentrations of NKP1339 in media containing different serum concentrations and fluorescence measured with a multimode microplate reader. Cellular uptake: The ruthenium uptake into colon cancer cells was examined for different serum concentrations by ICPMS measurement. Reverse-transcription quantitative polymerase chain reaction: Reversely transcribed cDNA levels were analyzed by EvaGreen® for the following ER stress key factor genes: GRP78, ATF4, IRE1a and CHOP as well as for XBP1 splicing by probes coupled to FAM and TET. Western blotting: Protein levels of GRP78, p-eIF2a, PERK, CHOP and the reference gene b-actin were analyzed by PAGE. Fluorescence microscopy: Cells were cultured on a cover slip, and Nrf2 translocation was investigated by immune fluorescence analysis. Results: Our investigations could show via ICP-MS measurements that NKP1339 uptake is increased in cells treated in media containing less FCS. Likewise it displays activity and induces reactive oxygen species (ROS) in a manner inversely dependent on serum concentration leading to a redox imbalance. Hereby it could be shown that the influence of serum proteins is multifaceted and significant. The redox imbalance leads to Nrf2 translocation into the nucleus which is known to induce antioxidant response element (ARE) gene translation. NKP-1339 was also shown to induce imbalance of the ER equilibrium, leading to a decrease of different proteins, e. g. GRP78, via a mechanism called ER-associated protein degradation (ERAD). Even though endoplasmic reticulum (ER) stress key factors were only mildly regulated on the mRNA basis, a significant upregulation of CHOP, p-eIF2a and PERK could be verified on protein level via Western blotting. Conclusion: In this study we revealed additional new underlying aspects of NKP-1339’s molecular mode of action. The role of ROS generation is highly serum-dependent, and ER imbalances support via the unfolded protein response, ER stress and ERAD the apoptotic pathway. Acknowledgment: This work was supported by the Mahlke nee´ Obermann Foundation. No conflict of interest.
S59 314 POSTER Phase 1 study of abemaciclib, a CDK 4 and 6 inhibitor, as a single agent for Japanese patients with advanced cancer S. Kondo1 , N. Yamamoto1 , K. Tamura1,2 , Y. Tanabe1,2 , S. Iwasa1 , A. Shimomura1 , Y. Shibasaki3 , K. Ogasawara3 , K. Turner-Jones4 , J. Mori3 , H. Asou3 , E. Michael Chan5 , Y. Fujiwara1 . 1 National Cancer Center Hospital, Department of Experimental Therapeutics, Tokyo, Japan; 2 National Cancer Center Hospital, Department of Breast and Medical Oncology, Tokyo, Japan; 3 Eli Lilly Japan K.K., Medicines Development Unit-Japan, Hyogo, Japan; 4 Eli Lilly and Company, Global PK/PD and Pharmacometrics, Indianapolis, USA; 5 Eli Lilly and Company, CDK 4/6 product team, Indianapolis, USA Background: Abemaciclib (LY2835219) is a small molecule inhibitor of cyclin dependent kinases 4 and 6 that has shown single agent clinical activity against multiple human tumors including lung cancer, breast cancer, and mantle cell lymphoma (Shapiro et al, ASCO 2013; Goldman et al, ASCO 2014; Patnaik et al, ASCO 2014; Tolaney et al, SABCS 2014; Morschhauser et al, ASH 2014). This study (NCT02014129) evaluated safety, pharmacokinetics (PK) and antitumor activity of abemaciclib in Japanese patients (pts) with advanced cancer up to maximum tolerated dose (MTD) as established in the previous phase 1 study (NCT01394016). Methods: Pts received abemaciclib at one of 3 dose levels (100, 150 or 200 mg) orally every 12 hours (Q12H) until disease progression or meeting any discontinuation criteria. Dose escalation was designed to proceed in cohorts of 3 or 6 pts until either 33% of pts in one cohort experienced dose-limiting toxicity (DLT) or the planned highest dose level was reached. Eligibility included ECOG performance status 1 and advanced cancer for which prior standard therapies had failed. Safety was assessed by CTCAE v4.03. The PK parameter estimates were computed using standard noncompartmental analysis methods. Antitumor activity was evaluated using RECIST v1.1. Results: A total of 12 Japanese pts started treatment with abemaciclib: 3 at 100 mg, 3 at 150 mg and 6 at 200 mg Q12H. The most common possibly related treatment-emergent adverse events (TEAEs) occurring in 5 pts were diarrhoea (75% for all grades, 8% G3), blood creatinine increased (75%, 0%), white blood cell decreased (42%, 33%), and decreased appetite (42%, 0%). Diarrhoea occurred in all 6 pts treated with 200mg Q12H; however, these events were manageable and no pts discontinued study treatment due to diarrhoea. One pt treated at 200 mg Q12H experienced DLT due to nausea (G2) which required dose omission. No deaths or possibly related G4/5 TEAEs were reported. The PK profile of abemaciclib was characterized by slow absorption (median Tmax ranging from 5 to 6 hours postdose) and mean terminal half-life between 16 and 22 hours. No relationship was detected between QTcF intervals and abemaciclib plasma concentrations. Conclusions: Abemaciclib showed tolerability and acceptable safety as a single agent for Japanese pts with advanced cancer up to MTD (200 mg Q12H). Antitumor activity is under investigation and updated data will be presented at the meeting. Conflict of interest: Ownership: Yuko Shibasaki, Ken Ogasawara and Joji Mori are employees of Eli Lilly Japan K.K. Hiroya Asou was an employee of Eli Lilly Japan K.K. Kellie Turner-Jones and Edward Michael Chan are employees of Eli Lilly and Company. Kellie TurnerJones and Edward Michael Chan have stock ownership of Eli Lilly and Company. Advisory Board: Yutaka Fujiwara is an advisory boad member of Novartis Pharmaceuticals Japan. Corporate-sponsored Research: Noboru Yamamoto received research funding for clinical trials from Chugai Pharmaceutical CO., Ltd, Eli Lilly Japan, TAIHO PHARMA, Eisai Co., Ltd, Quintiles, Astellas, Bristol-Myers Squibb, Novartis Pharmaceuticals Japan, Daiichi-Sankyo, Pfizer, Takeda Pharmaceutical CO., Ltd and Boehringer Ingelheim. Satoru Iwasa received research funding for clinical trials from Eli Lilly Japan. Yutaka Fujiwara received research funding for clinical trials from AstraZeneca and Eli Lilly Japan. 315 POSTER Impact of acid-reducing agents (ARAS) on the pharmacokinetics of palbociclib, a weak base with ph-dependent solubility, under differing food intake conditions W. Sun1 , K.J. Klamerus1 , L.M. Yuhas2 , S. Pawlak3 , A. Plotka4 , M. O’Gorman5 , M. Kosa6 , D. Wang1 . 1 Pfizer Inc, Clinical Pharmacology, San Diego, USA; 2 Pfizer Inc, Pharmaceutical Science, Groton, USA; 3 Pfizer Inc, Pfizer Clinical Research Unit, New Haven, USA; 4 Pfizer Inc, Statistics, Collegeville, USA; 5 Pfizer Inc, Clinical Pharmacology, Groton, USA; 6 Formerly Pfizer Inc, Clinical Pharmacology, San Diego, USA Background: Bioavailability of weakly basic drugs with pH-dependent solubility may be reduced when coadministered with ARAs, potentially