Published papers

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.

Background: Olaparib-induced anemia is a frequently occurring complication in patients with advanced ovarian cancer, fallopian tube cancer, or primary peritoneal cancer and is associated with a marked deterioration in patients’ health-related quality of life. This study aimed to clarify patient-specific risk factors for severe anemia in patients with advanced ovarian or breast cancer receiving olaparib monotherapy in a real-world setting. Methods: This multicenter, retrospective, observational study enrolled consecutively presenting patients with advanced ovarian or breast cancer who received olaparib monotherapy as maintenance or palliative treatment between April 2018 and December 2020 at three participating medical institutions in Japan. The primary endpoint was patient-associated risk factors underlying the onset of grade ≥3 anemia from olaparib treatment initiation to 90 days after treatment. Receiver operating characteristic curves were constructed and univariable and multivariable logistic regression analyses were performed to evaluate the association between patient-associated risk factors and grade ≥3 anemia. Results: Of 113 patients evaluated in this study, 32.7% (n = 37) had grade ≥3 anemia. Multivariable logistic regression analysis revealed that low baseline red blood cell (RBC) count (<3.3 × 106 cells/μL), low baseline hematocrit level (<35%), low baseline hemoglobin level (<11.6 g/dL), and breast cancer susceptibility (BRCA1/2) mutation were significantly associated with the onset of grade ≥3 anemia (adjusted odds ratio [OR], 3.39; 95% confidence interval [CI], 1.28–9.62; P = 0.017, adjusted OR, 3.63; 95% CI, 1.28–11.64; P = 0.021, adjusted OR, 3.89; 95% CI, 1.39–12.21; P = 0.014, and adjusted OR, 4.09; 95% CI, 1.55–11.67; P = 0.006, respectively). Conclusions: Our findings suggest that low baseline RBC count, low baseline hematocrit level, and low baseline hemoglobin level might be the patient-associated risk factors for severe anemia induced by olaparib monotherapy. Additionally, BRCA1/2 mutation was suggested to be a patient-related risk factor for anemia regardless of severity. Therefore, applying these patient-associated risk factors would help classify and screen patients at risk of severe anemia.

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.

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: Association between baseline medications plus neutrophil-to-lymphocyte ratio (NLR) and the effectiveness of immune checkpoint inhibitor (ICI) plus platinum doublet remains unknown, despite several reported prognostic models. We used real-world data to investigate whether baseline medications plus NLR predict survival outcomes in patients with advanced non-small-cell lung cancer (NSCLC) receiving ICI plus platinum doublet. Methods: This multicenter, retrospective, observational study conducted in Japan between December 2018 and March 2021 used real-world data of consecutive patients with advanced NSCLC who received ICI (pembrolizumab or atezolizumab) plus platinum doublet as first-line treatment. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The prognostic score for baseline medications plus NLR was weighted by regression β coefficients and used to categorize patients into good, intermediate, and poor prognoses groups. In addition, time-dependent receiver operating characteristic curve analyses and univariable and multivariable Cox proportional hazards models were constructed. Results: Overall, 241 patients were included. Poor prognosis was significantly associated with worse PFS (hazard ratio [HR]: 1.78; 95% confidence interval [CI]: 1.08-2.94; P = 0.025) and OS (HR: 3.59; 95% CI: 2.05-6.28; P < 0.001) than good prognosis. Harrell's C-index for this prognostic model was 0.648. Conclusions: Baseline medication plus NLR could predict progressively worse survival outcomes in patients with advanced NSCLC receiving ICI plus platinum doublet and could be used as a prognostic index for poor outcomes.

There is a lack of opportunities in Japan to engage in communication skills education about effective interactions between pharmacists and medical staff. This is despite the fact that current pharmacy education programs should be producing clinical experts in this area. Because of this, we delivered an educational program relating to building communication skills when working in a multidisciplinary team; 29 pharmacy students took part between May and November 2011. The program was based on two components: a lecture about communication skills by a facilitator (including “active listening”, “assertiveness” and “conflict management”), and a small group discussion (SGD) relating to decisions about opioid increases/rotation using a cancer pain case as an alternative opioid treatment. After the students finished the SGD, we distributed questionnaires to them and assessed outcomes using a five-grade Likert scale. As a result of the questionnaires, their mean understanding about opioid increasing and opioid rotation were 4.59 ± 0.68 and 4.48 ± 0.69, respectively. The mean implementation score of communication skills relating to “assertiveness” was 3.62 ± 0.94, which was significantly worse when compared with that of “active listening” (4.31 ± 0.60, P = 0.003). In addition, the mean satisfaction levels of the SGD group work and the overall educational program were 4.31 ± 0.81 and 4.38 ± 0.62, respectively. Care is required when interpreting the results given the study was limited to a single institution. However, these results suggest that this type of program may be useful for supporting pharmacy students to learn about communication skills. Improved skills should result in more effective communication, when pharmacists interact with medical staff.

Little information is available on the level of satisfaction of pharmacy students with pharmacist education before clinical pharmacy practice,although the current pharmacy education is rapidly changing to place more importance on nurturing clinical experts.In view of this,we performed a questionnaire survey to investigate deficiencies in pharmacist education that affected the satisfaction level of pharmacy students.A questionnaire was given to 59 pharmacy students between February 2007 and July 2008 and the responses were analyzed using categorical regression in order to objectively reflect the results in future pharmacist education.The survey revealed that pharmacist jobs that reduced the satisfaction level of pharmacy students included“making in-hospital pharmaceutical preparations”,“compliance management”,“clinical research coordination”,“drug purchasing management and stock control”,and“payment for injection drugs”,etc.,listed in order of degree of deficiency.Other items that influenced the satisfaction level were“nurturing medical professionals”,“team approach to medical treatment”,and“communication”.In this regard,75.4% of the pharmacy students responded that communication education between pharmacists and other medical staff was insufficient.The findings of our survey suggest that satisfaction level is a useful index to target in improving pharmacist education.

A retrospective study was carried out to compare the preventive effects of single and repeat treatment with dexamethasone (DEX) on delayed nausea and emesis in patients who had received carboplatin (CBDCA)-based combination chemotherapy. Sixty-four patients were evaluated. Efficacy was assessed using the nausea and emesis score, food intake score and the requirement for antiemetic medication. These forward scores were categorized as three-grade during the first 5 days after chemotherapy. Acute nausea and emesis were well controlled in both groups on day 1. Mean values of the nausea and emesis score on day 3 evening and the food intake score on day 4 morning in the repeat-treatment group was 1.31 ± 0.93 and 3.46 ± 1.03, respectively, which were significantly better when compared with the singletreatment group (2.00 ± 1.52; P = 0.028 and 2.79 ± 1.12; P = 0.018, respectively). Multivariate logistic regression analysis revealed that less frequent dispensing of antiemetic medication was significantly associated with the repeat-treatment group (adjusted odds ratio, 0.153; 95% confidence interval, 0.026-0.734; P = 0.018). These results suggest that repeat-dose DEX may be more effective than single-dose DEX for the prevention of delayed nausea and emesis after CBDCA-based combination chemotherapy.

There have so far been few reports of the pharmacokinetics of oxaliplatin in patients with renal impairment. This report describes the nephrotoxicity induced by repeated cycles of oxaliplatin in a Japanese colorectal cancer patient with moderate renal impairment(creatinine clearance(Ccr): 20-30mL/min). The patient was a 77-year-old male who had chronic renal impairment and received the modified FOLFOX6 repeated every 2 weeks. In cycle 8, the blood concentration of oxaliplatin(66 mg/m2)was measured as the platinum level to confirm the patient's safety. The serum ultrafiltrate concentrations of platinum were 800, 1, 000, 300, <200, and <200 ng/mLat 1, 2, 3 hr, 1 week, and 2 weeks after the start of infusion, respectively, which were closely comparable with the population pharmacokinetic data in Japanese patients with normal renal function. On the other hand, the serum creatinine value was gradually increased after cycle 6, resulting in a decrease of Ccr. The mean Ccr during day 1-59 and day 240-299were significantly different at 26. 5+/-2. 8(mean+/-SD)and 9. 6+/-1. 9mL/min, respectively. Consequently, the chemotherapy showed a complete response after 10 cycles, but the patient got dialysis on day 311. In conclusion, the repeated cycles of oxaliplatin cumulatively damaged the renal function in a Japanese patient with a moderate renal impairment.

Background and objective: Pertussis developed in Kagawa University Medical School and University Hospital in May 2007. To control the outbreak and prevent the infection of hospital inpatients, the Infection Control Team (ICT) carried out the prophylactic administration of erythromycin (EM) to hospital staff (1566 staff) who might be exposed to Bordetella pertussis. Methods: An oral dose of 1000 mg/day EM was given for 10 days. To assess compliance and estimate the frequency of adverse effect, the ICT conducted a questionnaire survey. Results and discussion: Of 942 respondents (response rate: 60.2%), 264 (28.0%) experienced some form of EM adverse effects, of which the most commonly reported involved digestive organ symptoms, e.g. diarrhoea (15.6%), stomachache (7.5%), nausea (3.6%), epigastric distress (2.1%) and abdominal distention (1.8%). More importantly, 246 participants (26.1%) stopped taking the EM before completing 10 days because of perceived adverse effects. Conclusion: These results indicate that EM appears to cause adverse effects more frequently than reported in the package insert in Japan. The prophylactic use of EM for pertussis infection is recognized in the guideline of the Centers for Disease Control and Prevention. However, this study suggests that attention should be paid to EM non-compliance during a pertussis outbreak, which could extend the duration of the outbreak and increase the number of affected patients.