Association between albumin-bilirubin grade and plasma trough concentrations of regorafenib and its metabolites M-2 and M-5 at steady-state in Japanese patients.

The aim of the present study was to determine whether the trough plasma concentrations (C0) of regorafenib and its metabolites, the N-oxide metabolite (M-2) and the desmethyl N-oxide metabolite (M-5), in 21 patients receiving regorafenib therapy were affected by albumin-bilirubin (ALBI) grade. Regorafenib was administered at dosages ranging from 40 to 160 mg once daily on a 3-week-on, 1-week-off cycle. C0 values of regorafenib and its major metabolites were measured by high-performance liquid chromatography on day 8 after treatment initiation. The C0 values of regorafenib and metabolites M-2 and M-5 were significantly lower in patients with ALBI grade 2 as compared with grade 1 (P = 0.023, 0.003 and 0.017, respectively). The total C0 of regorafenib and its metabolites was significantly higher in ALBI grade 1 patients relative to grade 2 (3.489 µg/mL vs. 1.48 µg/mL; P = 0.009). The median relative dose intensity (RDI) of patients categorized as ALBI grade 2 was significantly lower than that of grade 1 patients (21.9% vs. 62.9%; P = 0.006). In 15 colorectal cancer patients among the total 21 patients, patients with ALBI grade 2 (n = 9) had a significantly shorter median overall survival time than patients with grade 1 (n = 6; P = 0.013). Administering a low dose of regorafenib to patients with ALBI grade 2 reduces the RDI of regorafenib and lowers treatment efficacy, as an appropriate C0 of regorafenib is not maintained. Monitoring the C0 of regorafenib regularly is necessary to guide dose adjustment.

Effects of ABCB1 polymorphisms on the transport of ponatinib into the cerebrospinal fluid in Japanese Philadelphia chromosome-positive acute lymphoblastic leukaemia patients.

The effects of polymorphisms of ABCB1 and ABCG2 on the dose-adjusted plasma trough concentrations and cerebrospinal fluid (CSF)-to-plasma ratios of ponatinib were evaluated. Blood (C4 ) and CSF (CSF4 ) concentrations at 4 h after administration were determined. The median (95% confidence interval) CSF4 -to-C4 ratio of ponatinib in subjects homozygous for ABCB1 variants 1236T/T, 2677T/T + T/A or 3435T/T were significantly higher than that in a group of subjects with other genotypes (P = .026, .012 and .015, respectively). The median (95% confidence interval) CSF4 -to-C4 ratio of ponatinib in 4 patients with the combination of ABCB1 variants 1236T/T-2677T/T + T/A-3435T/T was 2.62% (1.42-3.42%); this ratio was significantly higher than that in subjects with other genotypes (1.08% [0.89-1.47%]; P = .006). The brain distribution of ponatinib was affected by ABCB1 polymorphisms and therefore seems to be modulated by P-glycoprotein at the blood-brain and blood-CSF barriers.

Impact of trough abiraterone level on adverse events in patients with prostate cancer treated with abiraterone acetate.

PURPOSE: We assessed the impact of plasma trough concentrations of abiraterone (ABI) and its metabolite Δ4-abiraterone (D4A) and related polymorphisms on adverse events (AEs) in patients with metastatic prostate cancer who received abiraterone acetate (AA). METHODS: This prospective study enrolled patients with advanced prostate cancer treated with AA between 2016 and 2021. Plasma trough concentrations of ABI and D4A were measured using high-performance liquid chromatography. The impact of HSD3B1 rs1047303, SRD5A2 rs523349, and cytochrome P450 family 3A member 4 rs2242480 polymorphisms on plasma concentrations of ABI and D4A and the incidence of AEs were also assessed. RESULTS: In 68 patients treated with AA, the median ABI and D4A concentrations were 18.1 and 0.94 ng/mL, respectively. The high plasma trough concentration of ABI (≥ 20.6 ng/mL) was significantly associated with the presence of any AE and its independent risk factor based on multivariable analysis (odds ratio, 7.20; 95% confidence interval (CI): 2.20-23.49). Additionally, a high plasma trough concentration of ABI was an independent risk factor of time to withdraw AA (hazard ratio, 4.89; 95% CI: 1.66-14.38). The risk alleles of three polymorphisms were not statistically associated with the ABI and D4A concentrations and the incidence of AEs. CONCLUSIONS: The plasma trough concentration of ABI is associated with the presence of AEs and treatment failure after AA administration. ABI concentration monitoring may be useful in patients with prostate cancer who received AA.

Hypoperfusion intensity ratio and CBV index as predictive parameters to identify underlying intracranial atherosclerotic stenosis in endovascular thrombectomy.

BACKGROUND AND PURPOSE: Intracranial atherosclerotic stenosis (ICAS)-related large vessel occlusion (LVO) is difficult to diagnose before endovascular thrombectomy (EVT) in an emergency. We hypothesized that hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index reflect collateral flow and would be useful parameters to predict underlying ICAS. MATERIALS AND METHODS: Clinical and perfusion imaging parameters of patients receiving EVT for LVO were reviewed retrospectively. Patients were divided into ICAS and embolism groups with angiographical findings. The association between prespecified parameters and underlying ICAS were assessed using multivariable logistic regression analyses. Discriminative ability was assessed using receiver operating characteristic analysis. RESULTS: Among 238 consecutive patients, 47 satisfied the inclusion criteria, including 10 with ICAS-related LVO. In ROC analyses, HIR showed good discrimination with a cutoff value of 0.22 (area under the curve, 0.85; 95%CI, 0.75-0.96; sensitivity, 0.84; specificity, 0.80) for underlying ICAS. CBV index showed excellent discrimination with a cutoff value of 0.90 (area under the curve, 0.92; 95%CI, 0.81-0.98; sensitivity, 0.92; specificity, 0.79). Multivariable logistic regression analysis revealed that HIR ≤ 0.22 (OR, 22.5; 95%CI, 2.9-177.0; P = 0.003) and CBV index ≥ 0.9 (OR, 75.7; 95%CI, 5.8-994.0; P < 0.001) were significantly associated with underlying ICAS. CONCLUSION: HIR ≤ 0.22 and CBV index ≥ 0.9 were associated with underlying ICAS and may predict underlying ICAS before EVT.

Effects of CYP3A4/5 and ABC transporter polymorphisms on osimertinib plasma concentrations in Japanese patients with non-small cell lung cancer.

The effects of polymorphisms in CYP3A4 (20230G > A), CYP3A5 (6986A > G), ABCB1 (1236C > T, 2677G > T/A, 3435C > T), ABCG2 (421C > A), and ABCC2 (-24C > T) on the area under the concentration-time curve (AUC) of osimertinib in 23 patients with non-small cell lung cancer were investigated. Blood sampling was performed just prior to and at 1, 2, 4, 6, 8, 12, and 24 h after osimertinib administration at the steady-state on day 15 after beginning therapy. The osimertinib AUC0-24 was significantly correlated with age (P = 0.038), serum albumin (P = 0.002), and serum creatinine (P = 0.012). Additionally, there were significant differences in the AUC0-24 of osimertinib among the groups administered vonoprazan, histamine 2-receptor antagonists or esomeprazole, and no acid suppressants (P = 0.021). By contrast, there were no significant differences in the AUC0-24 of osimertinib between genotypes of CYP3A4/5 or ABC transporters. Furthermore, there were no significant differences in the AUC0-24 of osimertinib between patients with diarrhea, skin rash, or hepatotoxicity and those without these conditions. In multivariate analysis, only serum albumin value was an independent factor predicting the AUC0-24 of osimertinib. Analysis of CYP3A4/5 and ABC transporter polymorphisms before osimertinib therapy may not predict the efficacy or side effects of osimertinib. The lower serum albumin values were associated with an increase in the AUC0-24 of osimertinib; however, further studies are needed to assess the factors contributing to the interindividual variability of osimertinib pharmacokinetics.

Effects of NR1I2 and ABCB1 Genetic Polymorphisms on Everolimus Pharmacokinetics in Japanese Renal Transplant Patients.

The purpose of this study was to evaluate the effects of NR1I2 (7635G>A and 8055C>T) and ABCB1 (1236C>T, 2677G>T/A, and 3435C>T) genetic polymorphisms on everolimus pharmacokinetics in 98 Japanese renal transplant patients. On day 15 after everolimus administration, blood samples were collected just prior to and 1, 2, 3, 4, 6, 9, and 12 h after administration. The dose-adjusted area under the blood concentration−time curve (AUC0-12) of everolimus was significantly lower in patients with the NR1I2 8055C/C genotype than in those with other genotypes (p = 0.022) and was significantly higher in male patients than female patients (p = 0.045). Significant correlations between the dose-adjusted AUC0-12 of everolimus and age (p = 0.001), aspartate transaminase (p = 0.001), and alanine transaminase (p = 0.005) were found. In multivariate analysis, aging (p = 0.008) and higher alanine transaminase levels (p = 0.032) were independently predictive of a higher dose-adjusted everolimus AUC0-12. Aging and hepatic dysfunction in patients may need to be considered when evaluating dose reductions in everolimus. In renal transplant patients, management using everolimus blood concentrations after administration may be more important than analysis of NR1I2 8055C>T polymorphism before administration.

Association between ABCC2 polymorphism and hematological toxicity in patients with esophageal cancer receiving platinum plus 5-fluorouracil therapy.

BACKGROUND: Platinum agents are taken up into cells by copper transporter (CTR) 1 (gene code: SLC31A1) and are excreted from cells by copper-transporting P-type adenosine triphosphatase (ATP7B) and multidrug resistance-associated protein (MRP) 2 (gene code: ABCC2). In addition, glutathione S transferase (GST) P1 is involved in the metabolism of platinum agents. The present study aimed to determine whether the rate of grade 3-4 hematological toxicity associated with platinum plus 5-fluorouracil (5-FU) therapy in 239 patients with esophageal cancer was affected by the SLC31A1 rs10981694A>C and rs12686377G>T, ATP7B rs9535828A>G, GSTP1 rs1695A>G, and ABCC2 -24C>T polymorphisms. METHODS: Chemotherapy consisted of protracted infusion of 5-FU (800 mg/m2/day) on days 1-5 and cisplatin or nedaplatin (80 mg/m2/day) on day 1. RESULTS: A total of 82 of 239 patients developed grade 3-4 hematological toxicity after chemotherapy. Univariate analysis showed that ABCC2 -24C/T + T/T genotypes (P = 0.038), radiation therapy (P = 0.013), baseline white blood cell count < 6000/µL (P = 0.003), and baseline neutrophil count < 3900/µL (P = 0.021) were statistically significant predictors of grade 3-4 hematological toxicity. Multivariate analysis revealed that ABCC2 -24C/T + T/T genotypes (P = 0.036), radiation therapy (P = 0.005), and baseline white blood cell count < 6000/µL (P < 0.001) were significant risk factors. CONCLUSIONS: We determined that ABCC2 -24C>T is significantly associated with grade 3-4 hematological toxicity after platinum plus 5-FU therapy. These findings might contribute to improved treatment strategies for patients with esophageal cancer.

Effects on monotherapy and reduction of antipsychotic drugs by clozapine therapy in Japanese patients with treatment-resistant schizophrenia.

WHAT IS KNOWN AND OBJECTIVE: The schizophrenia guidelines in Japan and many other countries describe clozapine as the first-choice drug for patients with treatment-resistant schizophrenia. However, there have been no reports to date on the effects of the introduction of clozapine on the prescription of other antipsychotics and concomitant drugs. METHODS: In this study, we retrospectively investigated the prescription of antipsychotics and concomitant drugs before vs 6 months after and 12 months after switching to clozapine. RESULTS AND DISCUSSION: Clozapine was introduced to 62 patients with treatment-resistant schizophrenia, and 51 patients continued on clozapine therapy. Six months after switching to clozapine, there was a significant decrease in the mean number of antipsychotic drugs (2.04 ± 0.75 vs 1.10 ± 0.30: p < 0.001) and in the mean chlorpromazine equivalent value (1024 ± 73 mg/day vs 781 ± 391 mg/day: p < 0.001) compared to before switching. Moreover, antipsychotic monotherapy increased from 24% to 90% after switching to clozapine. In addition, the number of concomitant benzodiazepines, anti-parkinson drugs and antidepressants also significantly decreased 6 and 12 months after switching to clozapine (p < 0.001 for benzodiazepines and anti-parkinson drugs, and p < 0.05 for antidepressants). WHAT IS NEW AND CONCLUSION: Our study suggests that switching to clozapine may reduce the use of antipsychotic combination therapy, and may also reduce the number of concomitant drugs.

Evaluation of the plasma concentration of ponatinib in a chronic myeloid leukaemia patient with ponatinib intolerance.

WHAT IS KNOWN AND OBJECTIVE: Some patients with chronic myeloid leukaemia (CML) cannot continue tyrosine kinase inhibitor (TKI) treatment due to intolerance associated with higher plasma concentration. CASE SUMMARY: A 76-year-old woman with chronic-phase CML who showed resistance/intolerance to pre-TKIs has been treated with ponatinib. A high ponatinib bioavailability was noted; therefore, we administered ponatinib 15 mg/3 d to avoid adverse events due to high exposure. Eventually, the patient achieved a major molecular response. WHAT IS NEW AND CONCLUSION: Monitoring of the ponatinib plasma concentration led to safe and effective CML management in a patient with higher drug bioavailability.

Results of a nationwide survey of Japanese pharmacists regarding the application of pharmacogenomic testing in precision medicine.

WHAT IS KNOWN AND OBJECTIVE: Pharmacogenomics (PGx) testing can be effective for supporting precision medicine. The purpose of this study was to assess the knowledge, attitude and practice behaviours of pharmacists in relation to such testing through a survey. We also aimed to identify potential obstacles to implementation of PGx testing by pharmacists and the characteristics of hospital pharmacists involved. METHODS: We performed a web-based survey regarding PGx in Japan. The survey contained a questionnaire related to PGx, which consisted of 30 items and was made accessible via the official Japanese Society of Pharmaceutical Health Care and Sciences (JSPHCS) website. The characteristics of hospital pharmacists associated with involvement in PGx testing were evaluated using univariate and multivariate analyses. RESULTS AND DISCUSSION: One thousand three-hundred and thirteen pharmacists responded to the survey. The results revealed that the majority of respondents recognized the role that germline PGx testing can play in determining individual drug responses and that pharmacists have embraced the potential of PGx testing to improve patient care. However, only 26% of pharmacists were involved in PGx testing. We also found that most respondents (81.0%) believed that the lack of insurance coverage for PGx testing was a major barrier to its clinical implementation. Hospital pharmacists involved in PGx testing included certified pharmacists in JSPHCS and pharmacists who had studied PGx in university; however, only 12.4% of pharmacists had received specific PGx-related education. WHAT IS NEW AND CONCLUSION: The findings of this survey highlight the necessity to increase the number of PGx tests covered by insurance, and the importance of effective education to inform and facilitate clinical implementation of PGx testing.

Effects of proprotein convertase subtilisin/kexin type 9 and nilotinib plasma concentrations on nilotinib-induced hypercholesterolaemia in patients with chronic myeloid leukaemia.

WHAT IS KNOWN AND OBJECTIVE: The purpose of this study was to investigate the relationships among nilotinib plasma trough concentration (C0 ), low-density lipoprotein (LDL) cholesterol, and PCSK9 plasma concentration in 31 patients with chronic myeloid leukaemia. METHODS: Plasma concentrations of nilotinib and PCSK9 were measured by high-performance liquid chromatography and enzyme-linked immunosorbent assays, respectively. RESULTS AND DISCUSSION: LDL cholesterol concentrations at 1 month after nilotinib treatment were significantly increased compared with those before therapy. The mean C0 (±SD) of nilotinib at 1, 2, and 3 months after nilotinib treatment were 645 ± 516, 902 ± 623, and 951 ± 1088 ng/mL, respectively. Mean PCSK9 concentrations at 3 months after nilotinib treatment were significantly higher than those at the start of therapy (320 vs 257 ng/mL, respectively, P = .019). When the change rate in the PCSK9 concentration induced by nilotinib was classified with a cut-off value of +40%, the change rate in LDL cholesterol in patients with a change rate in PCSK9 of ≥40% was significantly higher than that in patients with a PCSK9 change rate of <40% (67.1% vs 38.0%, P = .043); however, there were no differences in mean nilotinib C0 . WHAT IS NEW AND CONCLUSION: Nilotinib may lead to hypercholesterolaemia by increasing plasma concentrations of PCSK9 after indirect inhibition of mammalian target of rapamycin (mTOR) complex 1. In addition, certain patients seem to have high sensitivity for nilotinib in a signalling cascade of the PI3K/Akt/mTOR pathway, despite low plasma concentrations of nilotinib. Consequently, nilotinib-induced hypercholesterolaemia could not be predicted based on the plasma concentration of nilotinib.

Tacrolimus concentrations after renal transplantation in a mother-neonate dyad: Maternal, neonatal and breast milk measurements.

WHAT IS KNOWN AND OBJECTIVE: We aim to add to the few reports on tacrolimus concentrations in breast milk and in maternal, umbilical vein and neonatal blood after maternal renal transplantation. CASE SUMMARY: In a 30-year-old pregnant woman, the tacrolimus concentration at delivery was the same in maternal, umbilical vein and neonatal blood. The breast milk/maternal blood tacrolimus ratio ranged from 0.40 to 0.64. WHAT IS NEW AND CONCLUSION: The maternal and neonatal blood tacrolimus concentrations at birth are equivalent; thus, one must assume that maternal tacrolimus concentrations directly affect the foetus and/or neonate. Tacrolimus is not detectable in the neonate 3 weeks after birth, suggesting that there is minimal transfer through breast milk.

Pre-hospital Diagnosis of Large Vessel Occlusion in Patients Being Transported by Helicopter.

BACKGROUND: During the helicopter transportation of patients suspected of large vessel occlusion (LVO), an accurate and rapid decision-making process is required. AIMS: We attempted to create an algorithm for the pre-hospital diagnosis of the presence of LVO in patients suspected of stroke using data from patients transported urgently by helicopter. METHODS: One hundred and sixty-five patients transported by helicopter were divided into two subgroups: a training dataset and a validation dataset. We extracted clinical information obtained on site, the unadjusted score of the National Institutes of Health Stroke Scale, and previously reported pre-hospital scales as an LVO screen. On the basis of the analyses of these factors, an algorithm was devised to predict the presence of LVO and its predictive accuracy was evaluated using the validation dataset. RESULTS: Ischemic stroke with LVO was diagnosed in 36 out of 121 cases (29.8%) in the training dataset and in 10 out of 44 cases (22.7%) in the validation dataset. Combining five factors (conjugate deviation, upper limb paresis, atrial fibrillation, Japan Coma Scale ≥ 200, and systolic blood pressure ≥ 180), an algorithm was created to classify cases into six groups with different likelihoods of LVO presence. The algorithm predicted correctly 6 out of 10 cases in the validation dataset. Furthermore, it definitively ruled out 17 out of 34 cases in the validation dataset. CONCLUSIONS: Using the newly created algorithm, emergency staff could easily and accurately distinguish patients suitable for urgent endovascular thrombectomy from patients with non-LVO or stroke mimics.

ABCG2 C421A polymorphisms affect exposure of the epidermal growth factor receptor inhibitor gefitinib.

ATP-binding castle protein G2 (ABCG2) is thought to inhibit the activities of certain gefitinib transporters, thereby affecting drug pharmacokinetics. The C421A polymorphism affects the function and expression of ABCG2 on the cell membrane. Previous studies have shown that proton-pump inhibitors (PPIs) inhibit gefitinib absorption, as well as the function of ABCG2. We evaluated the plasma concentrations of gefitinib in patients with and without the ABCG2 C421A polymorphism, who were or were not taking PPIs. In total, 61 patients with advanced epidermal-growth-factor-positive non-small-cell lung cancer were enrolled in this study. They were treated with gefitinib at a dose of 250 mg per day. Plasma gefitinib concentration and ABCG2 C421A status were determined after 2 weeks. The patients were divided into CC- and CA/AA genotype groups. We compared the trough and peak gefitinib levels and the area under the curve (AUC) values for 24-h gefitinib concentrations. We also compared these parameters among four groups distinguished according to the presence or absence of the polymorphism and PPI use. The mean trough gefitinib level and AUC value for 24-h gefitinib concentration were significantly lower in the CA/AA group compared to the CC group (mean trough level: 333.2 vs. 454.5 ng/mL, respectively, P = 0.021; AUC: 9949.9 vs. 13,085.4 ng・h/mL, respectively, P = 0.034). Among patients taking PPIs, the mean trough gefitinib level was significantly lower in the CA/AA group than the CC group (220.1 vs. 340.5 ng/mL, respectively, P = 0.033). The CA/AA-type of ABCG2 C421A polymorphism may be associated with lower gefitinib plasma concentrations.

Therapeutic drug monitoring of regorafenib and its metabolite M5 can predict treatment efficacy and the occurrence of skin toxicities.

BACKGROUND: Regorafenib is a multiple tyrosine kinase inhibitor, and the use of this drug is approved for the treatment of cancers that are resistant to chemotherapy, which include advanced colorectal cancer, gastrointestinal stromal tumor, and hepatocellular carcinoma. However, the drug causes adverse events, including skin toxicities that require dose modification in approximately 75% of cases. At present, the blood concentration of regorafenib is not assessed in clinical settings; thus, we recently developed a method that can assess the blood concentration of the drug using high-performance liquid chromatography. METHODS: We measured the trough blood concentrations (Ctrough) of regorafenib and its metabolites (M2 and M5) in 14 and 4 patients with advanced colorectal cancer and gastrointestinal stromal tumor, respectively, using high-performance liquid chromatography. Then, the correlation between the Ctrough and therapeutic outcomes of regorafenib was analyzed. RESULTS: In patients who were receiving regorafenib 40-160 mg/day, the Ctrough values of regorafenib, M2, and M5 were 318-9467, 34-3594, and 38-3796 ng/mL, respectively. The difference in the values was significant. Although the specific factors influencing this difference were not elucidated, the Ctrough of regorafenib was extremely lower in some patients, even though the drug was administered at a standard dose, which may explain the lower response rate. Moreover, the Ctrough value of M5 was significantly correlated to the incidence of skin toxicities, which is the most frequent cause of dose modification. CONCLUSIONS: The use of regorafenib may not be suitable in patients with a low Ctrough value. To prevent skin toxicities, the Ctrough value of M5 should be monitored.

Effects of STAT3 polymorphisms and pharmacokinetics on the clinical outcomes of gefitinib treatment in patients with EGFR-mutation positive non-small cell lung cancer.

WHAT IS KNOWN AND OBJECTIVE: We investigated the correlations among signal transducer and activator of transcription 3 (STAT3) rs4796793C >G polymorphism, gefitinib pharmacokinetics and clinical responses in Japanese patients with non-small cell lung cancer receiving gefitinib therapy. METHODS: Forty-five patients were enrolled in this study. Plasma trough concentrations (C0 ) of gefitinib at the steady-state were measured by high-performance liquid chromatography. RESULTS AND DISCUSSION: Patients having a gefitinib C0 of at least ≥200 ng/mL had significantly longer PFS than patients having a C0 of <200 ng/mL (median [95% confidence interval (CI)] PFS: 11.0 [8.2-13.7] and 5.3 [0.0-12.0] months, respectively, P = .042). There were no significant differences in PFS between patients with STAT3 rs4796793C/C and G alleles; however, patients with STAT3 rs4796793C/C having a gefitinib C0 of ≥ 200 ng/mL had significantly longer progression-free survival (PFS) and overall survival (OS) than those with a C0 of <200 ng/mL (median [95% CI] PFS: 11.4 [4.1-18.6] and 3.0 [0.0-7.0] months, respectively, P = .008; median [95% CI] OS: 20.6 [7.4-33.7] and 12.6 [10.1-15.1] months, respectively, P = .042). In patients with the STAT3 rs4796793G allele, there were no significant differences in PFS and OS between the two gefitinib C0 groups. In addition, there were no significant differences in PFS or OS according to smoking, presence of proton pump inhibitor combination, or onset of side effects. WHAT IS NEW AND CONCLUSION: Clinical outcomes of gefitinib in patients with the STAT3 rs4796793C/C genotype depended on plasma concentrations of gefitinib. In addition to information regarding EGFR mutations, the STAT3 rs4796793C >G polymorphism and gefitinib C0 may be potential predictors of clinical outcomes after beginning of gefitinib therapy.

Drug interactions between warfarin and lenvatinib in a patient with the CYP2C9*1/*3 and VKORC1-1639G/A genotype.

WHAT IS KNOWN AND OBJECTIVE: Lenvatinib inhibits CYP2C8. (S)-Warfarin is metabolized to (S)-7-hydroxywarfarin by CYP2C9 and (S)-4'-hydroxywarfarin by CYP2C8. Here, we report drug interactions between warfarin and lenvatinib in a patient with CYP2C9*1/*3. CASE SUMMARY: The patient was administered warfarin. His international normalized ratio (INR) was 1.92 before lenvatinib administration. On day 8 after beginning 12 mg/day lenvatinib, plasma trough concentrations of lenvatinib and (S)-warfarin were 33.3 ng/mL and 0.67 µg/mL, respectively. On day 10, his INR increased to 3.48. WHAT IS NEW AND CONCLUSION: Lenvatinib-dependent (S)-warfarin inhibition could involve CYP2C9 and CYP2C8. After initiating warfarin plus lenvatinib, INR assays are necessary.

[Management using the plasma concentration of tyrosine kinase inhibitors for the treatment of chronic myelogenous leukemia: an update].

Imatinib, nilotinib, dasatinib, bosutinib, and ponatinib are tyrosine kinase inhibitors used to treat chronic myeloid leukemia (CML). Therapeutic drug monitoring (TDM) and target concentration intervention (TCI) are novel strategies that use concentration-controlled dosing (CCD) to attain a faster and more profound clinical response in patients with CML. The target plasma trough concentration (C0) of imatinib is 1,000 ng/ml to obtain a higher major molecular response (MMR) rate. Target nilotinib and bosutinib C0 of 900 and 62 ng/ml, respectively, are recommended to attain a better response, whereas a target ponatinib C0 of 21.3 ng/ml has been proposed to obtain a better response and decrease the risk of adverse events, such as vascular toxicity. Approaches for these four TKIs involve the use of TCI with specific target concentrations rather than TDM with a therapeutic range. Conversely, for dasatinib, a lower C0 of <4.33 ng/ml is the maximum toxic concentration recommended to avoid pleural effusion. Therefore, precision dosing using CCD of TKIs for CML could maximize the clinical benefit and minimize toxicity.

Curcumin analog, GO-Y078, overcomes resistance to tumor angiogenesis inhibitors.

Tumor angiogenesis inhibition is one of the most potent strategies in cancer chemotherapy. From past clinical studies, inhibition of the vascular endothelial growth factor pathway successfully treats malignant tumors. However, vascular endothelial growth factor inhibitors alone cannot cure tumors. Moreover, resistance to small molecule inhibitors has also been reported. Herein, we show the antiangiogenic potential of a newly synthesized curcumin analog, GO-Y078, that possibly functions through inhibition of actin stress fiber formation, resulting in mobility inhibition; this mechanism is different from that of vascular endothelial growth factor inhibition. In addition, we examined the detailed mechanism of action of the antiangiogenesis potential of GO-Y078 using human umbilical venous epithelial cells resistant to angiogenesis inhibitors (HUVEC-R). GO-Y078 inhibited the growth and mobility of HUVEC-R at 0.75 µmol/L concentration. Expression analyses by microarray and RT-PCR showed that expressions of genes including that of fibronectin 1 were significantly suppressed. Among these genes, fibronectin 1 is abundantly expressed and, therefore, seems to be a good target for GO-Y078. In a knockdown experiment using Si-oligo of fibronectin 1 (FN1), FN1 expression was decreased to half of that in mock experiments as well as GO-Y078. Knockdown of FN1 resulted in the suppression of HUVEC-R growth at 24 hours after treatment. Fibronectin is a key molecule contributing to angiogenesis that could be inhibited by GO-Y078. Thus, resistance to vascular endothelial growth factor inhibition can be overcome using GO-Y078.

Phase II Clinical Trial of Lenalidomide and Dexamethasone Therapy in Japanese Elderly Patients With Newly Diagnosed Multiple Myeloma to Determine Optimal Plasma Concentration of Lenalidomide.

BACKGROUND: The authors conducted a phase II clinical trial of lenalidomide and dexamethasone combination therapy in Japanese elderly patients with newly diagnosed multiple myeloma to evaluate its safety and efficacy and to determine whether safety and efficacy correlate with the plasma concentration of lenalidomide. METHODS: Forty patients received oral lenalidomide on days 1-21 of a 28-day cycle in addition to weekly doses of dexamethasone. Plasma concentrations of lenalidomide were measured, and the area under the concentration-time curve from 0 to 24 hours (AUC0-24) of lenalidomide was predicted using a formula the authors previously reported in this journal. RESULTS: The median age was 75.5 years. Twenty-one patients had renal impairment severe enough to require dose adjustment of lenalidomide. The median initial doses of lenalidomide and dexamethasone were 12.5 and 20 mg, respectively. The overall response rate was 68.6%, and the 2-year overall survival rate was 88.5%. There was no correlation between the response rate and plasma concentration of lenalidomide. Grade 3-4 adverse events (AEs) were observed in 57.5% of patients. The AUC0-24 of lenalidomide was significantly higher in patients with grade 3-4 AEs than in those who did not suffer from AEs (median = 4852.0 versus 2464.9 ng·h·mL, P = 0.027). Receiver-operating characteristic curve analysis showed that the AUC0-24 of lenalidomide was a good predictor of grade 3-4 AEs, with an area under the receiver-operating characteristic curve of 0.758 (95% confidence interval, 0.572-0.943, P = 0.027). The cutoff value for best prediction of grade 3-4 AEs was 2613.5 ng·h·mL (sensitivity 86.7%, specificity 54.5%). Multivariate logistic analysis confirmed the significance of this cutoff value. CONCLUSIONS: These data suggest that overexposure to lenalidomide could contribute to toxicity. Furthermore, the predicted cutoff value of AUC0-24 can be clinically used to prevent severe AEs.