Population Pharmacokinetics, Pharmacogenomics, and Adverse Events of Osimertinib and its Two Active Metabolites, AZ5104 and AZ7550, in Japanese Patients with Advanced Non-small Cell Lung Cancer: a Prospective Observational Study.

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.

Development and validation of a new liquid chromatography-tandem mass spectrometry assay for the simultaneous quantification of afatinib, dacomitinib, osimertinib, and the active metabolites of osimertinib in human serum.

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.

Lorlatinib-induced visual and auditory hallucinations: A case report.

Lorlatinib can cause visual and auditory hallucinations. And, it is necessary to keep in mind that hallucinations can persist even after discontinuation in patients who develop hallucinations while receiving lorlatinib.

Low-Dose Olanzapine Plus Granisetron and Dexamethasone for Carboplatin-Induced Nausea and Vomiting in Patients with Thoracic Malignancies: A Prospective Multicenter Phase II Trial.

BACKGROUND: Olanzapine is an inexpensive and durable agent for the treatment of chemotherapy-induced nausea and vomiting and is also superior to neurokinin-1 receptor antagonists in the control of nausea. This study aimed to investigate the efficacy and safety of a low dose of 5 mg olanzapine plus granisetron and dexamethasone for treatment of carboplatin (CBDCA)-induced nausea and vomiting in patients with thoracic malignancies. MATERIALS AND METHODS: We conducted a prospective, open-label, single-arm, multicenter, phase II trial in four centers in Japan. Registered patients were scheduled to receive area under the curve (AUC) ≥5 mg/mL per minute of CBDCA and had never received moderately to highly emetogenic chemotherapy. Patients received olanzapine 5 mg/day orally after supper for 4 days, in combination with granisetron and dexamethasone. Primary endpoint was complete response (CR; no emesis and no use of rescue medication) rate during the overall phase (0-120 hours). RESULTS: Between February 2018 and June 2020, 51 patients were enrolled, and 50 patients were evaluated. The CR rates in the overall (0-120 hours), acute (0-24 hours), and delayed phases (24-120 hours) were 94.0%, 100%, and 94.0%, respectively. No grade 3 or higher adverse effects of olanzapine were observed. CONCLUSION: Prophylactic antiemetic therapy with a low dose of 5 mg olanzapine plus granisetron and dexamethasone showed durable efficacy with an acceptable safety profile. This three-drug combination appears to be a reasonable treatment approach in patients with thoracic malignancies receiving an AUC ≥5 mg/mL per minute of CBDCA-based regimen. Clinical trial identification number: UMIN000031267. IMPLICATIONS FOR PRACTICE: The results of this phase II trial indicated that the prophylactic administration of low-dose of 5 mg olanzapine combined with granisetron and dexamethasone has promising activity with acceptable safety profile in patients with thoracic malignancy receiving high-dose carboplatin chemotherapy.

Factors Predicting the Therapeutic Response to Methotrexate in Japanese Patients with Rheumatoid Arthritis: A Hospital-Based Cohort Study.

Methotrexate (MTX) is used widely as a first-line drug for the treatment of rheumatoid arthritis (RA) worldwide. There are large interindividual differences in the therapeutic response to MTX, but it is not known which factors influence them. We therefore investigated predictive factors associated with the therapeutic response to MTX in a hospital-based cohort study. Japanese adult RA outpatients prescribed MTX were enrolled and their characteristics were collected from the electronic medical records. The European League Against Rheumatism (EULAR) response criteria were used as the response to MTX therapy. The observation period was 1 year after beginning MTX administration. Sixteen types of single-nucleotide polymorphisms were investigated using the real-time PCR method. Associations between the MTX response and patient characteristics were evaluated using the multivariate logistic regression model. Among 70 Japanese adult RA outpatients, 52 were classified as MTX responders. In multivariate analysis, patients with the solute carrier family 19 member 1 (SLC19A1) 80G>A A/A genotype had a better response than those with the A/G or G/G genotype, and patients with the C allele of γ-glutamyl hydrolase (GGH) 16T>C had a better response than those with the T/T genotype.This study showed that the therapeutic response to MTX in Japanese RA patients was associated with the genetic polymorphisms of SLC19A1 80G>A and GGH 16T>C in actual clinical practice.

Risk factors for rhabdomyolysis with HMG-CoA reductase inhibitors identified using a postmarketing surveillance database in Japan
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OBJECTIVE: To investigate quantitatively the risk factors for rhabdomyolysis or related symptoms associated with HMG-CoA reductase inhibitors (statins), we used the lipid-lowering drug database (32,157 patients) developed by the RAD-AR Council, Japan, based on the postmarketing surveillance (PMS) data of pharmaceutical companies to perform a nested case-control study. MATERIALS AND METHODS: Of 26,849 patients taking statins, the case group was composed of 51 patients who experienced rhabdomyolysis or related symptoms while taking statins, and the control group was 1,020 patients randomly selected from patients who did not experience rhabdomyolysis or related symptoms while taking statins. Relevant factors that can be extracted from the database were: sex, age, body mass index (BMI), statin use duration, complications, concomitant medication, and clinical laboratory test values. RESULTS: Among those taking statins, 51 experienced rhabdomyolysis or related symptoms. Factors differing significantly between the two groups by univariate analysis were age, duration of statin intake, combination drugs (Ca antagonists, angiotensin II receptor blocker (ARB), cardiac drugs, benzodiazepines, mucoprotective drugs, insulin, α-glucosidase inhibitors), clinical laboratory results (high-density lipoprotein cholesterol (HDL-C), aspartate aminotransferase, alkaline phosphatase, total bilirubin), and complications (alcoholic hepatitis). Conditional multivariate logistic analysis of these factors yielded adjusted/odds ratios of 8.82 for the concomitant administration of an ARB and 3.45 for increased AST and 3.20 for increased total bilirubin levels. CONCLUSION: Risk factors for rhabdomyolysis or related symptoms associated with taking statins were combination with ARB and increases in AST or total bilirubin levels.
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Risk factors for abnormal hepatic enzyme elevation by methotrexate treatment in patients with rheumatoid arthritis: A hospital based-cohort study.

OBJECTIVES: Methotrexate (MTX) is used as first-line treatment of rheumatoid arthritis (RA) worldwide. Large interindividual differences in MTX effectiveness and safety occur, and the most frequent adverse reaction is hepatotoxicity, although the main cause remains unknown. We investigated factors associated with MTX-induced hepatic enzyme elevation in a hospital-based cohort study. METHODS: Study participants were 114 Japanese adult RA outpatients prescribed MTX. Sixteen types of single-nucleotide polymorphisms were investigated using real-time PCR. Patient characteristics were collected from the electronic medical records. The onset of MTX-induced abnormal hepatic enzyme elevation was defined according to deviation from normal liver enzyme reference values during treatment. The observation period was 1 year after beginning MTX. Associations between MTX-induced hepatic enzyme elevation and patient characteristics were evaluated using the multivariate logistic regression model. RESULTS: Thirty-two patients experienced MTX-induced abnormal hepatic enzyme elevation. In multivariate analysis, MTX dosage, estimated glomerular filtration rate (eGFR), and genetic polymorphisms of ABCB1 3435C>T and ATIC 347C>G were associated with abnormal hepatic enzyme elevation. CONCLUSIONS: MTX-induced abnormal hepatic enzyme elevation in Japanese RA patients was associated with dosage and eGFR as nongenetic factors, and with ABCB1 3435C>T and ATIC 347C>G as genetic factors in this hospital-based cohort study.

Genetic polymorphisms of enzyme proteins and transporters related to methotrexate response and pharmacokinetics in a Japanese population.

BACKGROUND: Methotrexate (MTX) is currently the anchor drug widely used worldwide in the treatment of rheumatoid arthritis (RA). However, the therapeutic response to MTX has been shown to vary widely among individuals, genders and ethnic groups. The reason for this has been not clarified but it is considered to be partially due to several mechanisms in the cellular pathway of MTX including single-nucleotide polymorphisms (SNPs). The purpose of this study was to investigate the allelic frequencies in different ethnic and/or population groups in the 10 polymorphisms of enzyme proteins and transporters related to the MTX response and pharmacokinetics including MTHFR, TYMS, RFC1, FPGS, GGH, ABCB1, ABCC2 and ABCG2 in unrelated healthy Japanese adults and patients with RA. METHODS: Ten polymorphisms, methylenetetrahydrofolate reductase (MTHFR) 1298, thymidylate synthase (TYMS) 3'-UTR, reduced folate carrier 1 (RFC1) 80 and-43, folypolyglutamyl synthase (FPGS) 1994, γ-glutamyl hydrolase (GGH) 452 and-401, the ABC transporters (ABCB1 3435, ABCC2 IVS23 + 56, ABCG2 914) of enzyme proteins and transporters related to MTX response and pharmacokinetics in 299 unrelated healthy Japanese adults and 159 Japanese patients with RA were investigated to clarify their contributions to individual variations in response and safety to MTX and establish personalized MTX therapy. SNPs were evaluated using real-time polymerase chain reaction (PCR). RESULTS: Comparison of allelic frequencies in our study with other ethnic/population groups of healthy adults and RA patients showed significant differences in 10 polymorphisms among healthy adults and 7 among RA patients. Allelic frequencies of MTHFR 1298 C, FPGS 1994A and ABCB1 3435 T were lower in Japanese than in Caucasian populations and those of ABCC2 IVS23 + 56 C and ABCG2 914A were higher in Japanese than in Caucasian/European populations in both healthy adults and RA patients. Allelic frequencies of MTHFR 1298 C, GGH-401 T, ABCB1 3435 T, and ABCG2 914A were higher in healthy Japanese adults than in an African population, and those of RFC1 80A, RFC1-43C and ABCC2 IVS23 + 56 C in healthy Japanese adults were lower than in Africans. However, no significant differences were seen in the distribution of allelic frequencies between healthy Japanese adults and RA patients. CONCLUSION: The variations in allelic frequencies in different ethnic and/or population groups in healthy adults and RA patients may contribute to individual variations in MTX response and toxicity.

Preliminary study for predicting better methotrexate efficacy in Japanese patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammatory status, joint destruction, disability, and pain. Methotrexate (MTX) has been confirmed to reduce disease activity and delay or stabilize the development of bone erosions. However, major drawbacks are that patients show great interindividual variability in response to MTX and the unpredictable occurrence of side effects. A strategy for personalized MTX treatment to predict its efficacy and toxicity has not yet been determined. To establish personalized MTX therapy in Japanese patients with rheumatoid arthritis, we performed a preliminary study for predicting better methotrexate efficacy including single-nucleotide polymorphisms (SNPs) for MTX-related transporters/enzymes. METHODS: Disease control status (good or poor) was judged by the number of Disease Activity Scores (DAS28) of <2 for 6-12 months. The response index R was calculated by the improved area under the curve (AUC) of the DAS28 score for 0-3 or 0-6 months by dividing the cumulative dose of MTX during 0-3 or 0-6 months, respectively. Genotyping of alleles of RFC1 80G > A, RFC1 -43 T > C, FPGS 1994G > A, GGH 401C > T, MTHFR 1298A > C, and TYMS 3'-UTR (-6/+6) was performed using the real-time PCR system. RESULTS: Seven of 21 patients were judged as good responders in terms of disease control, and the remainder as poor responders. For 0-3 months after starting MTX administration, the median cumulative dose and improved DAS28 AUC in the good and poor response groups were 96.0 mg and 25.4 and 118.0 mg and 23.4, respectively. For 0-6 months, the median cumulative dose and improved DAS28 AUC in the good and poor response groups were 192.0 mg and 51.0 and 214.0 mg and 47.6, respectively. Statistically significant differences between the 2 groups in the 0-6-month period were observed in DAS28 AUC improvement and index R. A slight tendency for a correlation between G/G genotypes and A allele genotypes in RFC1 80 genotypes was observed, although it did not reach statistical significance. CONCLUSION: This study suggested that aggressive RA treatment with MTX from the early period of administration is necessary to obtain a good response after 6 months, although no SNPs predicting a better treatment response to MTX were identified.

Sex Differences in mRNA Expression of Reduced Folate Carrier-1, Folypolyformyl Glutamate Synthase, and γ-Glutamyl Hydrolase in a Healthy Japanese Population.

Sex differences in the prevalence of autoimmune diseases such as rheumatoid arthritis (RA) are well known, but little is known about those differences in relation to therapeutic response. Reduced folate carrier-1 (RFC-1), folypolyformyl glutamate synthase (FPGS), and γ-glutamyl hydrolase (GGH) are important transporters and enzymes that convert methotrexate (MTX) in the body. This study investigated the sex differences in mRNA expression of RFC-1, FPGS, and GGH in 190 unrelated healthy Japanese people. The genotypes and mRNA expression were determined using the real-time PCR method. Significant differences between men and women were observed in RFC-1, FPGS, and GGH mRNA expression. The mRNA expression of FPGS and GGH was greater in women than that in men, but the expression of RFC-1 was less in the former than the latter. In stratified analysis by genotype, significant differences in sex-specific mRNA expression were observed in G/G of FPGS, C/C of GGH 452, and C/C of GGH -401. All showed greater mRNA expression in women than in men. In the 5 single-nucleotide polymorphisms RFC-1 80G>A, RFC-1 -43T>C, FPGS 1994G>A, GGH 452C>T, and GGH -401C>T examined, the FPGS 1994 G/G (1.46-fold), GGH 452 C/C (2.16-fold), and GGH -401 C/C (2.68-fold) genotypes showed significantly higher mRNA expression in women than in men. Healthy Japanese adults in this study showed sex-specific differences in mRNA expression that differed among RFC-1, FPGS, and GGH. Therefore, the relationship between genetic polymorphisms and mRNA expression including sex differences might contribute to the variation in the efficacy/toxicity of MTX in patients with RA.