Published papers

A 0.04% mitomycin C (MMC) ophthalmic solution is not commercially available and is prepared in hospitals as required. The physical properties and stability of the MMC ophthalmic solution have not been clarified because of a lack of data. This study aimed to assess the stability of the MMC ophthalmic solution under various storage conditions. The MMC ophthalmic solution was prepared by dissolving 2 mg of MMC in 5 mL of saline solution. Each batch of ophthalmic solution was stored under three conditions [cold/shaded light, room temperature/shaded light, and room temperature/scattered light (approximately 4000 lx)], and MMC concentration was determined using high-performance liquid chromatography on days 0, 1, 3, 5, 7, 14, and 21. The expiry date was calculated based on the results of the degradation analysis. pH measurements and bacterial culture tests were conducted for each storage condition. The MMC concentrations on day 21 under cold/shaded light, room temperature/shaded light, and room temperature/scattered light were 340, 287, and 227 µg/mL, respectively. MMC concentrations decreased over time, and the decrease was highest when the samples were stored at room temperature and exposed to light, and lowest under cold conditions and protected from light. The pH of MMC solutions was 5.8 after preparation, which increased to 6.9 with time under all storage conditions. Culture tests did not detect any bacteria under any storage conditions. The MMC ophthalmic solution was most stable under cold/shaded conditions, and our study clarifies its expiry date for clinical use.

Reports on the therapeutic drug monitoring (TDM) of second- and third-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer patients are limited and are required to improve the safety of EGFR-TKI therapy. Some EGFR-TKIs have active metabolites with similar or higher potency compared with the parent compounds; thus, monitoring the parent compound as well as its active metabolites is essential for truly effective TDM. In this study, we developed and validated a method that simultaneously quantifies second- and third-generation EGFR-TKIs (afatinib, dacomitinib, and osimertinib) and the active metabolites of osimertinib, AZ5104 and AZ7550, in the human serum using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The clinical application of the method was also evaluated. The analytes were extracted from a 100 μL serum sample using a simple protein precipitation method and analyzed using LC-MS/MS. Excellent linearity of calibration curves was observed at ranges of 2.5–125.0 ng/mL for afatinib, 2.5–125.0 ng/mL for dacomitinib, 4.0–800.0 ng/mL for osimertinib, 1.0–125.0 ng/mL for AZ5104, and 2.5–125.0 ng/mL for AZ7550. The precision and accuracy were below 14.9% and within ± 14.9% of the nominal concentrations, respectively. The mean recovery was higher than 94.7% and the coefficient of variation (CV) was lower than 8.3%. The mean internal-standard normalized matrix factors ranged from 94.6 to 111.9%, and the CVs were lower than 9.7%. This analytical method met the acceptance criteria of the U.S. Food and Drug Administration guidelines. The method was also successfully applied to the analysis of 45 clinical samples; it supports the efficient and valuable analysis for TDM investigations of EGFR-TKIs.

Pancreatic cancer is associated with a poor prognosis; thus, there is an urgent need to develop new and effective treatments. Ingenol mebutate (IM), which is isolated from the latex of Euphorbia peplus, was recently shown to be effective against pancreatic cancer cell lines; however, its mechanism of action has not been fully elucidated. In this study, we focused on the less drug-sensitive pancreatic cancer cell line Panc-1 and compared IM to commercially available anticancer drugs using cell survival assays. In addition, we aimed to identify novel biomolecules that may be involved in the mechanism of action of IM using RNA sequencing, western blotting, and inhibition assays. The IC50 values after 72 h of exposure to IM and SN-38, drugs to which the Panc-1 cells are most sensitive among the tested anticancer agents, were 43.1 ± 16.8 nM and 165 ± 37 nM, respectively. IM showed a cytostatic effect equal to or greater than that of the clinically used pancreatic cancer therapeutic drugs. RNA sequencing and protein expression analysis revealed that expression of stimulator of interferon genes (STING) increased at low IM concentration, whereas cell viability decreased. Co-exposure of IM and STING inhibitor, H-151, to Panc-1 or MIA PaCa-2 cell lines canceled the growth-inhibitory effects of IM alone. In conclusion, IM may have an efficacy comparable to that of existing pancreatic cancer therapeutic agents on the less drug-sensitive Panc-1 cell line and the immune-related molecule STING plays a role in the mechanism of action of IM.

Background: Potential novel strategies for adverse event (AE) management of osimertinib therapy, including therapeutic drug monitoring and the use of biomarkers, have not yet been fully investigated. This study aimed to evaluate (1) the relationship between exposure to osimertinib, especially its active metabolites (AZ5104 and AZ7550), and AEs, and (2) the relationship between germline polymorphisms and AEs. Methods: We conducted a prospective, longitudinal observational study of 53 patients with advanced non-small cell lung cancer receiving osimertinib therapy from February 2019 to April 2022. A population pharmacokinetic model was developed to estimate the area under the serum concentration–time curve from 0 to 24 h (AUC0–24) of osimertinib and its metabolites. Germline polymorphisms were analyzed using TaqMan® SNP genotyping and CycleavePCR® assays. Results: There was a significant association between the AUC0–24 of AZ7550 and grade ≥ 2 paronychia (p = 0.043) or anorexia (p = 0.011) and between that of osimertinib or AZ5104 and grade ≥ 2 diarrhea (p = 0.026 and p = 0.049, respectively). Furthermore, the AUC0–24 of AZ5104 was significantly associated with any grade ≥ 2 AEs (p = 0.046). EGFR rs2293348 and rs4947492 were associated with severe AEs (p = 0.019 and p = 0.050, respectively), and ABCG2 rs2231137 and ABCB1 rs1128503 were associated with grade ≥ 2 AEs (p = 0.008 and p = 0.038, respectively). Conclusion: Higher exposures to osimertinib, AZ5104, and AZ7550 and polymorphisms in EGFR, ABCG2, and ABCB1 were related to higher severity of AEs; therefore, monitoring these may be beneficial for osimertinib AE management.

Study Objective: Establish methods for measuring cefmetazole (CMZ) concentrations conduct a pharmacokinetic/pharmacodynamic (PK/PD) analysis using unbound CMZ concentrations for extended-spectrum β-lactamase producing enterobacterales (ESBL-E) and investigate optimal dosing regimens for not undergoing hemodialysis (non-HD) and undergoing hemodialysis (HD) patients. Design: Prospective observational study. Patients: Included patients treated with CMZ who provided written informed consent and were admitted to the Tokyo Bay Urayasu Ichikawa Medical Center between August 2021 and July 2022. Measurements: Total and Unbound CMZ concentration was measured by high-performance liquid chromatography (HPLC) with solid-phase extraction and ultrafiltration. Setting: Determining the CMZ dosing regimen involved modified creatinine clearance (CLCR) with measured body weight (BW) using the Cockcroft–Gault equation. For non-HD patients, blood samples were collected during at least three points. For patients undergoing HD, 1 g was administered via intravenous infusion, or rapid intravenous injection after HD, or 30 min before the end of HD. Blood samples were collected before HD (pre-HD), and 1 and 3 h after starting HD and post-HD. All blood samples were collected at steady-state. Patient information was collected from electronic medical records. An unbound PK model was constructed for the non-HD patients. A nomogram was constructed using Monte Carlo simulations with a 90% probability of target attainment at 70% free time above the minimum inhibitory concentration (MIC). For the HD patients, a nomogram was used to determine the optimal dosing regimen for each HD schedule. Main Results: CMZ measurement methods were established. A model analysis of unbound PK in 37 non-HD patients incorporated creatinine clearance (CLCR) using the Cockcroft–Gault equation, albumin (ALB) for clearance and body weight (BW) for the volume of distribution. In Monte Carlo simulations, nomograms corresponding to the MIC (known and unknown) were generated for each covariate. Using the nomogram, non-HD patients with an ESBL-E MIC of 8 mg/L, a BW of 60 kg, an ALB of 25 g/L, and a CLCR of 60 mL/min required administration of 2 g every 6 h (1- and 3-h infusions). Unbound PK model parameters were calculated for 7 HD patients, and the optimal dosing regimens following PK/PD were determined for each HD schedule. In HD patients, the regimen after and during HD was established using a treatment that was effective up to an ESBL-E MIC of 4 mg/L. Conclusions: The nomogram for CMZ regimens established by PK/PD analysis of measured CMZ concentrations enables optimal CMZ dosing for ESBL-E-infected patients.

This study aimed to clarify the optimal value for the unbound cefmetazole concentration to remain above the minimum inhibitory concentration (MIC) (fT≥MIC) for efficacy of de-escalation to cefmetazole in patients with bacteremic urinary tract infection by extended-spectrum β-lactamase-producing Escherichia coli. This double-center retrospective observational study was conducted at Tokyo Bay Urayasu Ichikawa Medical Center and Keio University Hospital from January 2012 to October 2022. Efficacy was determined via clinical evaluation (mortality rate, recurrence rate, vital changes) and bacteriological evaluation, and the optimal fT≥MIC was calculated via receiver operating characteristic curve analysis. As a result, the number of patients evaluated were 40 (35 and 5 in the treatment success and treatment failure groups, respectively). Univariate analysis showed that fT≥MIC, recurrence rate, and MIC for cefmetazole against bacteria were significantly different for the two groups (p<0.05). Receiver operating characteristic curve analysis showed that the optimal fT≥MIC indicating efficacy was 57% (area under the curve: 0.94, 95% confidence interval: 0.86–1.00, p=0.002). All patients with fT≥MIC ≥ 57% had successful treatment, whereas the frequency of treatment failure was high among those with fT≥MIC <57%. The optimal fT≥MIC for the clinical efficacy of de-escalation to cefmetazole in patients with bacteremic urinary tract infection by extended-spectrum β-lactamase-producing E. coli was fT≥MIC ≥ 57%. This finding would be useful for optimal dosing of cefmetazole.

Patient risk factors related to coagulopathy and bleeding when using cefmetazole (CMZ) have not yet been identified, and no models exist to predict side effects during CMZ treatment. Moreover, reports that examine which patients should be careful when using CMZ to ensure safety are lacking. Our objective was to understand risk factors for elevated international normalized ratio (INR) in patients using CMZ and to develop a predictive model for INR elevation using a risk score to enable safe administration of CMZ. This multicenter, retrospective, and observational study was conducted in Tokyo Bay Urayasu Ichikawa Medical Center and Keio University Hospital using data from patients being treated with CMZ. Patients were classified into INR-elevated or non-INR-elevated groups. Univariate and multivariate analyses were performed to calculate the adjusted odds ratios (aOR) and 95% confidence intervals (CI). The actual probability of an elevated INR and probability of an elevated INR predicted by the regression β coefficients were calculated and classified into four categories according to the risk score. Binomial logistic regression analysis revealed that liver disorder (aOR, 5.65; 95% CI, 1.69–18.91; risk scores, 2), nutritional risk (aOR, 6.32; 95% CI, 3.14–12.74; risk scores, 2), no-diabetes mellitus (aOR, 4.53; 95% CI, 1.34–15.26; risk scores, 2), and warfarin use (aOR, 98.44; 95% CI, 7.05–1375.50; risk scores, 5) were significantly associated with INR elevation. The predicted incidence probabilities of INR elevation were<5% (low risk), 5–<30% (medium risk), 30–<90% (high risk), and ≥ 90% (very high risk). The model validity showed a good fit (AUC, 0.79; 95% CI, 0.73–0.85, P<0.001). We identified risk factors that contribute to INR elevation and constructed a model to predict INR elevation using the risk score. Using this predictive model enables the appropriate use of CMZ in a safe manner.

Inhibiting body fat accumulation is important for the prevention of obesity. In Japan, three Kampo medicines are commonly used to treat obesity: bofutsushosan, boiogito, and daisaikoto. To compare the influences of these Kampo medicines on the intestinal microbiota, it is necessary to conduct a simultaneous investigation using the same mouse model under the same experimental conditions. C57BL/6J mice were divided into five groups: normal chow (NC), high-fat diet (HFD), HFD + 3% bofutsushosan extract (BTS), HFD + 3% boiogito extract (BOT), and HFD + 3% daisaikoto extract (DST). Epididymal white adipose tissue (WAT) weight, mesenteric WAT weight, serum triglyceride levels, and serum total cholesterol levels were measured. Additionally, total bacteria, alpha diversity, beta diversity, and bacterial composition in stool samples were measured. Body weight and epididymal WAT weight gain were significantly inhibited in the BTS-treated group and DST-treated group, but not in the BOT-treated group, compared with the HFD control group. Additionally, serum total cholesterol levels were significantly lower in the DST-treated group than in the HFD group. Specific intestinal bacteria, Clostridium sensu stricto 1, Erysipelatoclostridium, Roseburia, and the Lachnospiraceae NK4A136 group, were significantly changed in the Kampo-treated groups compared with the HFD group, and each of them was correlated with body weight gain, body fat rate, epididymal WAT weight, or mesenteric WAT weight. Our simultaneous investigation of BTS, BOT, and DST under the same conditions clearly demonstrated different changes in the intestinal microbiota and different effects on fat accumulation as well as their association among the three Kampo medicines.

Background: Dasatinib, nilotinib, and bosutinib, second-generation tyrosine kinase inhibitors (TKIs), and ponatinib, a third-generation TKI, are approved pharmaceuticals used in the treatment of chronic myeloid leukemia (CML). Although liquid chromatography-tandem mass spectrometry assays for simultaneous quantification of the four TKIs in human serum have been reported in the literature, a high-performance liquid chromatography (HPLC) assay that simultaneously quantifies these compounds has not yet been developed. This study aims to establish and validate an efficient HPLC analytical method using a photodiode array (PDA) detector for the simultaneous quantification of the four TKIs. Methods: Calibration standards were prepared by serial dilution of serum samples containing the four TKIs, followed by solid-phase extraction. The four TKIs were eluted in order within 10 min using a binary HPLC gradient system. Results: The calibration ranges were 2–500 ng/ml for dasatinib, 100–5000 ng/ml for nilotinib, and 10–500 ng/ml for bosutinib and ponatinib. Intra-day and inter-day precision and accuracy values were found to be in accordance with the U.S. Food and Drug Administration guidelines. The recovery rates were 92.9%–96.0%, 80.7%–86.1%, 91.6%–99.0%, and 86.4%–92.6% for dasatinib, nilotinib, bosutinib, and ponatinib, respectively. Conclusion: To the best of our knowledge, this is the first report of an HPLC-PDA analytical method that allows efficient simultaneous quantification of the four TKIs in the serum of patients with CML. We believe that the method developed herein can improve the efficiency of therapeutic drug monitoring in patients with CML in clinical practice.

We aimed to clarify whether various antipsychotics ameliorate cisplatin-induced pica behavior in mice using a drug repositioning approach. Mice were administered cisplatin (12.5 mg/kg, i.p.) with or without olanzapine (1 mg/kg, i.p.), asenapine (4 mg/kg, i.p.), mirtazapine (5 mg/kg, i.p.) or standard three-drug antiemetics (granisetron [0.5 mg/kg, i.p.], fosaprepitant [25 mg/kg, i.p.], and dexamethasone [3 mg/kg, i.p.]). Kaolin, food, and water intake, and spontaneous motor activity on the day before and seven consecutive days after the cisplatin administration were measured using a telemetry system. At the primary endpoint, kaolin intake was significantly higher at day three in the cisplatin group than in the pre-treatment and saline groups (p < 0.05). Additionally, kaolin intake was not significantly higher in cisplatin with olanzapine, asenapine, and mirtazapine groups for seven days than in the pre-treatment group. At the secondary endpoint, cisplatin decreased the food and water intake, and spontaneous motor activity in a time-dependent manner. Three antipsychotics failed to improve the cisplatin-induced decrease in food and water intake, and spontaneous motor activity. The findings suggest that prophylactic administration of antipsychotics besides olanzapine may improve cisplatin-induced nausea and vomiting in a delayed phase and de-escalate standard 3-drug antiemetics.

Background: Nivolumab and pembrolizumab are the standard treatments for patients with advanced non-small-cell lung cancer (NSCLC). While there are reports on several inflammatory indices and the prognosis of patients with cancer, no study has combined baseline medication with the neutrophil-to-lymphocyte ratio (NLR) to predict clinical outcomes. This study investigated the efficacy of baseline medications plus NLR to predict the effectiveness of nivolumab and pembrolizumab in a real-world clinical setting. Methods: We conducted a single-center retrospective observational study of consecutive patients with advanced NSCLC who received nivolumab or pembrolizumab as first-line, second-line, or beyond treatment between December 2015 and November 2018 at the National Cancer Center Hospital in Japan. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. The drug-based prognostic score for baseline medications plus NLR was weighed based on the regression β coefficients. The multivariable Cox proportional hazard model was used to assess the association between the prognostic score-stratified groups and survival outcomes. Results: In total, 259 patients were evaluated in this study. A prognostic score calculated from the baseline medications plus NLR was used to categorize the patients into good (score 0), intermediate (scores 1–2), and poor (scores 3–6) -prognosis groups. The multivariable Cox proportional hazard model revealed a significant association between the poor-prognosis group and reduced OS. The hazard ratio of OS was 1.75 (95% confidence interval: 1.07–2.99; P = 0.031). In contrast, no association between these prognosis groups and PFS was observed. Conclusions: The findings suggest that the baseline medications with nivolumab or pembrolizumab plus NLR could lead to progressively shorter survival outcomes in patients with advanced NSCLC and could be used as a prognostic index for poor outcomes. However, to ascertain the clinical application of these findings, these concomitant medications need further validation in a large-scale multicenter study.