Nobuo Mochizuki

Antifungal Activity of Micafungin in Serum

ABSTRACT We have evaluated the antifungal activity of micafungin in serum by using the disk diffusion method with serum-free and serum-added micafungin standard curves. Serum samples from micafungin-treated patients have been shown to exhibit adequate antifungal activity, which was in proportion to both the applied dose and the actual concentration of micafungin measured by high-performance liquid chromatography. The antifungal activity of micafungin in serum was also confirmed with the broth microdilution method.

TAS-102 plus bevacizumab for patients with metastatic colorectal cancer refractory to standard therapies (C-TASK FORCE): an investigator-initiated, open-label, single-arm, multicentre, phase 1/2 study

BACKGROUND In patients with heavily treated metastatic colorectal cancer, TAS-102-a combination of trifluridine and tipiracil-has shown a significant overall survival benefit compared with placebo. In preclinical models, TAS-102 plus bevacizumab has shown enhanced activity against colorectal cancer xenografts compared with that for either drug alone. In this phase 1/2 study, we assessed the activity and safety of TAS-102 plus bevacizumab. METHODS We did this investigator-initiated, open-label, single-arm, multicentre, phase 1/2 trial of TAS-102 plus bevacizumab in four cancer centres in Japan. Eligible patients were aged 20 years or older; had histologically confirmed unresectable, metastatic colorectal adenocarcinoma; were refractory or intolerant to fluoropyrimidine, irinotecan, oxaliplatin, anti-VEGF therapy, and anti-EGFR therapy (for tumours with wild-type KRAS); and had no previous treatment with regorafenib. Patients had to have an Eastern Cooperative Oncology Group performance status of 0 or 1. Using a dose de-escalation design in phase 1, the recommended phase 2 dose (RP2D) was determined for TAS-102 (35 mg/m2 given orally twice daily on days 1-5 and 8-12 in a 28-day cycle for level 1) plus bevacizumab (5 mg/kg, administered by intravenous infusion for 30 min every 2 weeks). In phase 2, patients received the RP2D. The primary endpoint was centrally assessed progression-free survival at 16 weeks, analysed in the first 21 patients to be enrolled and treated with the RP2D who had at least one imaging assessment. This study is completed and registered with the University Hospital Medical Information Network, number UMIN000012883. FINDINGS Between Feb 25, 2014, and July 23, 2014, we enrolled 25 patients with metastatic colorectal cancer: six patients in phase 1 and 19 patients in phase 2. The six patients who received TAS-102 at level 1 experienced no dose-limiting toxicities and this was deemed the RP2D. Nine of 21 patients who received the RP2D did not have a centrally assessed progression event; 16-week progression-free survival was 42·9% (80% CI 27·8-59·0). The most common grade 3 or worse adverse events as assessed in all 25 patients were neutropenia (18 [72%] patients), leucopenia (11 [44%]), anaemia (four [16%]), febrile neutropenia (four [16%]), and thrombocytopenia (three [12%]). Treatment-related serious adverse events were reported in three (12%) patients. No treatment-related deaths occurred. INTERPRETATION TAS-102 plus bevacizumab has promising activity with manageable safety, suggesting that this combination might become a potential treatment option for patients with metastatic colorectal cancer in a refractory setting. FUNDING Taiho Pharmaceutical.

Phase I trial of GBS-01 for advanced pancreatic cancer refractory to gemcitabine.

GBS‐01, an extract from the fruit of Arctium lappa L. is an orally administered drug rich in arctigenin, which has been reported to exert antitumor activity by attenuating the tolerance of cancer cells to glucose deprivation. We investigated the maximum tolerated dose of GBS‐01 based on the frequency of the dose‐limiting toxicities (DLTs) and pharmacokinetics in patients with advanced pancreatic cancer refractory to gemcitabine. GBS‐01 was given orally at escalating doses from 3.0 g (containing 1.0 g burdock fruit extract) to 12.0 g q.d. A DLT was defined as a grade 4 hematological toxicity and grade 3 or 4 non‐hematological toxicity appearing during the first 28 days of treatment. Fifteen patients (GBS‐01 dose level 1 [3.0 g], three patients; dose level 2 [7.5 g], three patients; and dose level 3 [12.0 g], nine patients) were enrolled. None of the patients at any of the three dose levels showed any sign of DLTs. The main adverse events were increased serum γ‐glutamyl transpeptidase, hyperglycemia, and increased serum total bilirubin; however, all the toxicities were mild. Of the 15 patients, 1 showed confirmed partial response and 4 patients had stable disease. The median progression‐free and overall survival of the patients were 1.1 and 5.7 months, respectively. The pharmacokinetic study revealed a high bioavailability of arctigenin and rapid conjugation of the drug with glucuronic acid. The recommended dose of GBS‐01 was 12.0 g q.d, and favorable clinical responses were obtained. This trial was registered at UMIN‐CTR (http://www.umin.ac.jp/ctr/index-j.htm), identification number UMIN000005787.

Liquid chromatographic method for the determination of sirolimus in blood using electrochemical detection

Therapeutic drug monitoring of sirolimus (rapamycin) is important for immunosuppressive therapy in solid organ transplantation. We have developed a simple and reliable method for determining blood concentrations of sirolimus using reversed-phase HPLC with electrochemical detection (ECD). The E(2) potential was set at +900 mV. The potential of guard cell was set at +950 mV and that of the E(1) cell at +400 mV. The method was linear for a concentration range of 1-50 ng/mL when 0.5 mL blood was used. The correlation coefficients of all standard curves were greater than or equal to 0.999. The limit of detection was 0.5 ng/mL. The inter-assay precision ranged from 3.22 to 7.48%, and the coefficient of variation (CV) for a quality control sample at 10 ng/mL was 7.48% with a bias of 8.4% from the target value. The intra-assay precision ranged from 0.72 to 3.71%, and the CV for a quality control sample at 10 ng/mL was 0.72% with a bias of 6.8% from the target value. In a solid organ transplant recipient, trough concentrations of sirolimus were well within the analytic range of the HPLC/ECD procedure. The method described here is suitable for management of sirolimus therapy in solid organ transplantation.

A simple and reliable method for determining plasma concentration of dehydroxymethylepoxyquinomicin by high performance liquid chromatography with mass spectrometry

We have developed a simple and reliable method for determining plasma concentration of dehydroxymethylepoxyquinomicin (DHMEQ), a new low molecular weight NF-kappaB inhibitor, using high performance liquid chromatography with mass spectrometry (LC-MS). An experiment of mass spectrometry with electrospray ionization in the negative ionization mode was performed to detect ion transitions at m/z 260.05 [M-H](-) for DHMEQ and 240.29 for mefenamic acid as an internal standard. The samples were purified using liquid-liquid extraction with ethyl acetate. The method yielded a standard curve which was linear for the concentration range of 0.1-125 ng/mL when 0.05 mL plasma was used. The correlation coefficients of all standard curves were greater than or equal to 0.999. The limit of detection was 50 pg/mL (signal/noise >3). Daily fluctuation of plasma standard curve was small. The intra- and inter-assay precision ranged from 2.84 to 4.76% (n=6) and 2.91 to 7.03% (n=6), respectively. The LC-MS technique described provides a simple and reliable liquid chromatographic method for the determination of DHMEQ level and for use in studies involving pharmacokinetics.

Change in plasma lactate concentration during arctigenin administration in a phase I clinical trial in patients with gemcitabine-refractory pancreatic cancer

Arctigenin is evaluated for antitumor efficacy in patients with pancreatic cancer. It has an inhibitory activity on mitochondrial complex I.Therefore, plasma lactate level of patients after arctigenin administration was evaluated for biomarker of clinical response and/or adverse effect. Plasma lactate level in 15 patients enrolled in a Phase I clinical trial of GBS-01 rich in arctigenin was analyzed by colorimetric assay. Statistical analyses for association of plasma lactate and clinical responses, pharmacokinetics of arctigenin, and background factors of each patient by multivariate and univariate analyses.In about half of the patients, transient increase of lactate was observed. Correlation between plasma lactate level and pharmacokinetic parameters of arctigenin and its glucuronide conjugate, and clinical outcome was not detected. Regarding to the determinant of lactate level, only slight association with liver function test was detected. Plasma lactate level is primary determined by reutilization rather than production for antitumor effect and dose not serve as a biomarker. Arctigenin, inhibition of mitochondrial complex I, plasma lactate concentration, phase I clinical trial of GBS-01, Cori cycle.

Abstract CT213: Arctigenin, an antiausterity agent shows high safety and promising clinical response in phase I clinical trial in patient with gemcitabine-refractory pancreatic cancer

Cancer microenvironment is characterized by severe hypoxia and nutrient deprivation, especially glucose. Cancer depends largely on glycolysis for energy production (Warburg effect), therefore tumor hypoxia is mainly caused by poor blood supply despite vigorous angiogenesis. Severe tumor hypoxia and glucose deprivation promote tumor progression and affects tumor behavior especially resistance to anticancer drugs. We have focused on the invention of agents that cancel cancer cells9 ability to tolerate poor oxygen and glucose supply (antiausterity) and found many agents including kigamicin, pyrvinium pamoate, and arctigenin. Because antitumor activity and safety profile were excellent in preclinical test, arctigenin was chosen for the first compound for clinical trial. Arctigenin is rich in fruit of Arctinum lappa which is filed in Japanese Pharmacopoeia, we have invented an extraction method to enrich arctigenin (GBS-01, Kracie Pharma, Ltd.) and used in clinical trial. GBS-01 contained arctigenin about 10% in weight. Pancreatic cancer is characterized for its hypovascularity and severe hypoxia in cancer tissue has been reported and, in addition, only limited benefit of chemotherapy has been achieved so far. Patients, material and design of trial: Pancreatic cancer patients refractory to gemcitabine were selected for the phase I clinical trial of GBS-01. Primary endpoint of the trial was determination of recommended dose by assessing DLT in dose escalation study from 1 g/day to 4 g/day, corresponding to 100 mg to 400 mg arctigenin/day. GBS-01 administration was continued until either unacceptable adverse effcts or evident progression of the cancer appeared. Pharmacokinetic study was also carried out as a secondary endpoint. Results:Fifteen patients were enrolled and three patients were not evaluated because of early stopping due to progression of the disease. Results: Among 12 patients evaluated, no DLT was observed. No serious adverse effects on bone marrow, liver and kidney function was observed. Pharmacokinetic study revealed that arctigenin is efficiently absorbed and rapidly conjugated with glucuronic acid. Serum concentration of arctgenin glucuronide was about 100 to several hundreds higher than that of arctigenin, indicating glucuronidation in the first pass. Urinary secretion of arctigenin and its glucuronide was more than half of administered dose in more than half of patients, indicating high bioavailability. Regarding clinical tumor response, partial response was observed in one patient at 2.5 g/day (level 2) for 2 months followed by 2four months stable disease (SD) and SD was observed in other four patients. Median progression free survival was 1.05 months and median overall survival was 5.68 months.Conclusion: Arctigenin showed high bioavailability, high safety profile, and promising clinical responses. Citation Format: Hiroyasu Esumi, Satoshi Owada, Rumi Fujioka, Katsuya Tsuchihara, Atsushi Ohtsu, Aihiro Sato, Masafumi Ikeda, Nobuo Mochizuki, Satoshi Kishino, Takanori Kawashima, Satoshi Yomoda. Arctigenin, an antiausterity agent shows high safety and promising clinical response in phase I clinical trial in patient with gemcitabine-refractory pancreatic cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT213. doi:10.1158/1538-7445.AM2014-CT213