Association of the modified Glasgow prognostic score and prognostic nutritional index with duration of oral anamorelin administration in patients with cancer cachexia: a retrospective cohort study.

BACKGROUND: The modified Glasgow Prognostic Score (mGPS) and Prognostic Nutritional Index (PNI) are indicators of nutritional status in cancer patients; however, the effects of baseline mGPS and PNI on the duration of administration of the ghrelin receptor agonist anamorelin, which is used to treat cachexia in patients with cancer, are unclear. This study aimed to clarify the association of mGPS and PNI with the duration of oral anamorelin administration for patients who did not have beneficial effects from anamorelin. METHODS: The attending physician determined the duration of oral anamorelin administration based on discontinuation due to cancer progression, poor efficacy, adverse events, or death. RESULTS: The 12-week continuation rate of oral anamorelin was 30.4%. Univariate analysis revealed that an Eastern Cooperative Oncology Group performance status (ECOG-PS) of ≥2 (P < .001), concurrent chemotherapy (P = .002), albumin level (P = .005), C-reactive protein level (P = .013), and a mGPS of 2 (P = .014) were statistically significant predictors of the 12-week continuation rate of oral anamorelin. In the multivariate analysis, a mGPS of 2 remained a significant risk factor, and the ECOG-PS and concurrent chemotherapy had no effect on the association between the mGPS and 12-week continuation rate of oral anamorelin. CONCLUSION: Patients with a mGPS of 2, compared with mGPS of 0 or 1, are less likely to maintain oral anamorelin therapy, regardless of the ECOG-PS or concurrent chemotherapy. Therefore, it is necessary to consider initiating anamorelin administration at mGPS 0 or 1.

Overexposure to venetoclax is associated with prolonged-duration of neutropenia during venetoclax and azacitidine therapy in Japanese patients with acute myeloid leukemia.

PURPOSE: An observational study was conducted to evaluate the pharmacokinetics of venetoclax and its impact on the efficacy and safety for Japanese patients with acute myeloid leukemia (AML) treated with venetoclax and azacitidine therapy. METHODS: The association between the plasma concentration, after the first cycle of azacitidine and venetoclax therapy, and the efficacy and safety was evaluated in 33 patients with untreated or relapsed/refractory AML. RESULTS: Full dose of venetoclax was administered to all patients. Venetoclax treatment was 28 day long in 82% of patients; the relative dose intensity of azacitidine was 82%. Trough concentration was significantly higher among patients with complete remission (CR) and CR with incomplete hematologic recovery (CRi) than those with the morphologic leukemia-free state and partial remission, and no response groups (P = 0.01). Median duration of grade 3 neutropenia was 28 days (range 8-46 days). Area under the concentration-time curve (AUC0-24) was significantly higher among patients with protracted grade 3 neutropenia (≥ 28 days) than those with a shorter duration (< 28 days) (P = 0.03); multivariate analysis revealed that a higher AUC0-24 was a significant predictor of a longer duration of neutropenia (odds ratio 54.3, P = 0.007). CONCLUSION: Plasma concentrations of venetoclax were variable in Japanese patients with AML. Higher plasma concentrations were associated with CR/CRi and protracted grade 3 neutropenia. Therefore, it is essential to adjust the duration of venetoclax administration based on individual pharmacokinetic data to limit total drug exposure, reduce severe neutropenia, and achieve higher efficacy.

[Determination of Plasma Concentrations of Imatinib by a Novel Automated Analyzer Based on High-Performance Liquid Chromatography].

LM1010 HPLC is an emerging automated method designed for use in clinical settings. The aim of this study was to compare the analytical performance of LM1010 with the performance of traditional HPLC and LC-MS/MS in the measurement of plasma concentrations of imatinib. Seventy-eight plasma samples from 20 patients (14 men and 6 women) were collected. Plasma concentrations of imatinib in samples from the same patient were analyzed simultaneously using LM1010, HPLC and LC-MS/MS (LSI Medience Corporation). Strong correlations were seen in pairwise comparisons of results from the LM1010 and HPLC methods, the LM1010 and LC-MS/MS methods, and the LC-MS/MS and HPLC methods (Spearman's r=0.936, 0.906, and 0.953, respectively); however, the results from the LC-MS/MS method showed a positive proportional bias in comparison with the results from the LM1010 and HPLC methods, according to Deming analyses (slope=1.064 and 1.105, respectively). In Bland-Altman analyses, the LC-MS/MS method showed a positive mean bias of 98.6 and 112 ng/mL in comparison with the LM1010 and HPLC methods, respectively. Notably, results obtained using the LM1010 method were comparable to those using the HPLC method (positive mean bias=13.6 ng/mL; 95% confidence interval, -7.9-35.1 ng/mL). Biochemical parameters or drugs taken concomitantly with imatinib were not found to affect the bias of the LM1010 method. The LM1010 method can be applied to routine therapeutic drug monitoring of imatinib.

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.

Drug interaction between letermovir and voriconazole after allogeneic hematopoietic cell transplantation.

Letermovir has been approved for the prevention of cytomegalovirus (CMV) infection after allogeneic hematopoietic stem cell transplantation (HCT). Letermovir is a cytochrome P450 (CYP) 2C19 inducer. Voriconazole, which is a broad-spectrum triazole antifungal agent, is mainly metabolized by CYP2C19. Thus, voriconazole trough concentration may decrease due to the drug interaction between voriconazole and letermovir. This study aimed to clarify the effects of letermovir on voriconazole trough concentration in allogeneic HCT recipients. We retrospectively examined voriconazole trough concentration in 24 allogeneic HCT recipients who had letermovir for prevention of CMV infection. The median voriconazole C/D ratios significantly decreased after starting letermovir from 0.25 L/kg to 0.11 L/kg (p < 0.01), and increased after discontinuing letermovir from 0.15 L/kg to 0.24 L/kg (p = 0.02). The median fold change of voriconazole trough concentration during letermovir administration was 0.40. Our results suggest that voriconazole trough concentration decreases when voriconazole is combined with letermovir in allogeneic HCT recipients. Therefore, close therapeutic drug monitoring of voriconazole trough concentration is warranted in allogeneic HCT recipients after starting or discontinuing letermovir.

Negative feedback regulation of ErbB4 tyrosine kinase activity by ERK-mediated non-canonical phosphorylation.

ErbB4 receptor tyrosine kinase has four different isoforms that are classified based on variants in the extracellular juxtamembrane domain (JM-a and JM-b) and the C-terminal region (CYT-1 and CYT-2). Here, we used the JM-b/CYT-1 isoform to investigate the roles of serine/threonine phosphorylation in MEK-ERK-dependent feedback inhibition. TPA as an activator of the ERK pathway markedly induced ErbB4 phosphorylation at Thr-674, the conserved common feedback site in the intracellular JM domain, which resulted in the downregulation of tyrosine autophosphorylation. We also identified Ser-1026 as an ErbB4-specific ERK target site in the CYT-1 region. Moreover, double mutations (Thr-674/Ser-1026 to Ala) significantly upregulated ErbB4 activation, indicating that Thr-674 and Ser-1026 are cooperatively involved in negative feedback regulation. Given the fact that ErbB4 mutation is one of the most common genetic alterations in melanoma cells, we demonstrated that a typical oncogenic ErbB4 mutant was resistant to the negative feedback regulation to maintain a highly active status of tyrosine kinase activity. Together, these findings indicate that feedback mechanisms are key switches determining oncogenic potentials of ErbB receptor kinases.