A Review of Approaches to Potentiate the Activity of Temozolomide against Glioblastoma to Overcome Resistance.

A glioblastoma (GBM) is one of the most aggressive, infiltrative, and treatment-resistant malignancies of the central nervous system (CNS). The current standard of care for GBMs include maximally safe tumor resection, followed by concurrent adjuvant radiation treatment and chemotherapy with the DNA alkylating agent temozolomide (TMZ), which was approved by the FDA in 2005 based on a marginal increase (~2 months) in overall survival (OS) levels. This treatment approach, while initially successful in containing and treating GBM, almost invariably fails to prevent tumor recurrence. In addition to the limited therapeutic benefit, TMZ also causes debilitating adverse events (AEs) that significantly impact the quality of life of GBM patients. Some of the most common AEs include hematologic (e.g., thrombocytopenia, neutropenia, anemia) and non-hematologic (e.g., nausea, vomiting, constipation, dizziness) toxicities. Recurrent GBMs are often resistant to TMZ and other DNA-damaging agents. Thus, there is an urgent need to devise strategies to potentiate TMZ activity, to overcome drug resistance, and to reduce dose-dependent AEs. Here, we analyze major mechanisms of the TMZ resistance-mediated intracellular signaling activation of DNA repair pathways and the overexpression of drug transporters. We review some of the approaches investigated to counteract these mechanisms of resistance to TMZ, including the use of chemosensitizers and drug delivery strategies to enhance tumoral drug exposure.

Zenker's peroral endoscopic myotomy for management of large Zenker's diverticulum.

BACKGROUND: Zenker's diverticulum peroral endoscopic myotomy (zPOEM) is a minimally invasive treatment strategy for Zenker's diverticulum, with excellent results for management of small-to-moderate Zenker's diverticulum. We evaluated its use in the management of large Zenker's diverticulum. METHODS: This was a retrospective multicenter cohort study across 11 international centers including adult patients with large Zenker's diverticulum ≥ 40 mm treated by zPOEM between March 2017 and March 2022. The primary outcome was clinical success (dysphagia score ≤ 1 without need for further intervention). Secondary outcomes included technical success (complete myotomy as intended), adverse events (AEs), and rate of recurrence. RESULTS: 83 patients (male 62.7 %, mean age 72.6 [SD 11.5] years) underwent zPOEM for treatment of large Zenker's diverticulum (median size 50 mm, interquartile range [IQR] 41-55 mm, range 40-80 mm). The zPOEM procedure was technically successful in 82 patients (98.8 %), with a mean procedure time of 48.7 (SD 23.2) minutes. Clinical success was achieved in 71 patients (85.5 %). Median (IQR) symptom scores improved significantly from baseline for dysphagia (2 2 3 vs. 0 [0-2]; P < 0.001), regurgitation (3 2 3 4 vs. 0 [0-0]; P < 0.001), and respiratory symptoms (2 [0-3] vs. 0 [0-0]; P < 0.001). Among patients achieving clinical success, only one recurrence (1.4 %) was recorded during a median follow-up of 12.2 months (IQR 3-28). Post-procedure AEs, all mild to moderate, occurred in four patients (4.8 %). CONCLUSION: This study demonstrated safe and effective use of zPOEM in the management of large Zenker's diverticulum.

Pharmacokinetics of Levetiracetam Seizure Prophylaxis in Severe Traumatic Brain Injury.

BACKGROUND: Drug pharmacokinetics (PK) are altered in neurocritically ill patients, and optimal levetiracetam dosing for seizure prophylaxis is unknown. OBJECTIVE: This study evaluates levetiracetam PK in critically ill patients with severe traumatic brain injury (sTBI) receiving intravenous levetiracetam 1000 mg every 8 (LEV8) to 12 (LEV12) hours for seizure prophylaxis. METHODS: This prospective, open-label study was conducted at a level 1 trauma, academic, quaternary care center. Patients with sTBI receiving seizure prophylaxis with LEV8 or LEV12 were eligible for enrollment. Five sequential, steady-state, postdose serum levetiracetam concentrations were obtained. Non-compartmental analysis (NCA) and compartmental approaches were employed for estimating pharmacokinetic parameters and projecting steady-state trough concentrations. Pharmacokinetic parameters were compared between LEV8 and LEV12 patients. Monte Carlo simulations (MCS) were performed to determine probability of target trough attainment (PTA) of 6 to 20 mg/L. A secondary analysis evaluated PTA for weight-tiered levetiracetam dosing. RESULTS: Ten male patients (5 LEV8; 5 LEV12) were included. The NCA-based systemic clearance and elimination half-life were 5.3 ± 1.2 L/h and 4.8 ± 0.64 hours. A one-compartment model provided a higher steady-state trough concentration for the LEV8 group compared with the LEV12 group (13.7 ± 4.3 mg/L vs 6.3 ± 1.7 mg/L; P = 0.008). Monte Carlo simulations predicted regimens of 500 mg every 6 hours, 1000 mg every 8 hours, and 2000 mg every 12 hours achieved therapeutic target attainment. Weight-tiered dosing regimens achieved therapeutic target attainment using a 75 kg breakpoint. CONCLUSION AND RELEVANCE: Neurocritically ill patients exhibit rapid levetiracetam clearance resulting in a short elimination half-life. Findings of this study suggest regimens of levetiracetam 500 mg every 6 hours, 1000 mg every 8 hours, or 2000 mg every 12 hours may be required for optimal therapeutic target attainment. Patient weight of 75 kg may serve as a breakpoint for weight-guided dosing to optimize levetiracetam therapeutic target attainment for seizure prophylaxis.

Brain pharmacokinetics and metabolism of the AMP-activated protein kinase selective inhibitor SBI-0206965, an investigational agent for the treatment of glioblastoma.

PURPOSE: Emerging evidence suggests that 5' Adenosine Monophosphate-Activated Protein Kinase (AMPK), a key regulator of cellular bioenergetics, is a novel target for the treatment of glioblastoma (GBM), a lethal brain tumor. SBI-0206965, an aminopyrimidine derivative, is a potent AMPK inhibitor being investigated for the treatment of GBM. Here we characterized the systemic and brain pharmacokinetics (PK) and hepatic metabolism of SBI-0206965. METHODS: We performed intracerebral microdialysis to determine brain partitioning of SBI-0206965 in jugular vein cannulated rats. We assessed systemic PK of SBI-0206965 in rats and C57BL/6 mice following oral administration. Employing human, mouse, and rat liver microsomes we characterized the metabolism of SBI-0206965. RESULTS: SBI-0206965 is quickly absorbed, achieving plasma and brain extracellular fluid (ECF) peak levels within 0.25 - 0.65 h. Based on the ratio of Cmax and AUC in brain ECF to plasma (corrected for protein binding), brain partitioning is ~ 0.6-0.9 in rats. However, the compound has a short elimination half-life (1-2 h) and low relative oral bioavailability (~ 0.15). The estimated in-vitro hepatic intrinsic clearance of SBI-0206965 in mouse, rat and human was 325, 76 and 68 mL/min/kg, respectively. SBI-0206965 metabolites included desmethylated products, and the metabolism was strongly inhibited by ketoconazole, a CYP3A inhibitor. CONCLUSION: SBI-0206965 has adequate brain permeability but low relative oral bioavailability which may be due to rapid hepatic metabolism, likely catalyzed by CYP3A enzymes. Our observations will facilitate further development of SBI-0206965, and/or other structurally related molecules, for the treatment of GBM and other brain tumors.

Impact of prior treatment on feasibility and outcomes of Zenker's peroral endoscopic myotomy (Z-POEM).

BACKGROUND: Zenker's peroral endoscopic myotomy (Z-POEM) is a novel procedure for the management of symptomatic Zenker's diverticulum. This study aims to report the technical feasibility and outcomes of Z-POEM in the management of Zenker's diverticulum after prior failed interventions. METHODS: Patients with persistent or recurrent symptoms after prior endoscopic and/or surgical intervention for Zenker's diverticulum were retrospectively included. The primary outcome was clinical success, defined as complete or near complete resolution of dysphagia (dysphagia score of 0 or 1) without the need for repeat endoscopic or surgical intervention during follow-up. RESULTS: Z-POEM was technically successful in 30/32 patients (93.8 %). Clinical success was achieved in 29/30 patients (96.7 %), and Z-POEM significantly reduced the median (interquartile range [IQR]) dysphagia score of patients from 2 (1 - 2) to 0 (0) (P < 0.001) over a median duration of follow up of 166 days (IQR 39 - 566). Four patients (12.5 %) had adverse events (two inadvertent mucosotomies and two leaks found on post-procedural esophagrams). CONCLUSION: Z-POEM is feasible, safe, and effective in the majority of patients with recurrent symptoms after prior surgical or endoscopic interventions.

Phosphoinositide 3-Kinase (PI3K) Reactive Oxygen Species (ROS)-Activated Prodrug in Combination with Anthracycline Impairs PI3K Signaling, Increases DNA Damage Response and Reduces Breast Cancer Cell Growth.

RIDR-PI-103 is a novel reactive oxygen species (ROS)-induced drug release prodrug with a self-cyclizing moiety linked to a pan-PI3K inhibitor (PI-103). Under high ROS, PI-103 is released in a controlled manner to inhibit PI3K. The efficacy and bioavailability of RIDR-PI-103 in breast cancer remains unexplored. Cell viability of RIDR-PI-103 was assessed on breast cancer cells (MDA-MB-231, MDA-MB-361 and MDA-MB-453), non-tumorigenic MCF10A and fibroblasts. Matrigel colony formation, cell proliferation and migration assays examined the migratory properties of breast cancers upon treatment with RIDR-PI-103 and doxorubicin. Western blots determined the effect of doxorubicin ± RIDR-PI-103 on AKT activation and DNA damage response. Pharmacokinetic (PK) studies using C57BL/6J mice determined systemic exposure (plasma concentrations and overall area under the curve) and T1/2 of RIDR-PI-103. MDA-MB-453, MDA-MB-231 and MDA-MB-361 cells were sensitive to RIDR-PI-103 vs. MCF10A and normal fibroblast. Combination of doxorubicin and RIDR-PI-103 suppressed cancer cell growth and proliferation. Doxorubicin with RIDR-PI-103 inhibited p-AktS473, upregulated p-CHK1/2 and p-P53. PK studies showed that ~200 ng/mL (0.43 µM) RIDR-PI-103 is achievable in mice plasma with an initial dose of 20 mg/kg and a 10 h T1/2. (4) The prodrug RIDR-PI-103 could be a potential therapeutic for treatment of breast cancer patients.

Diverticular per oral endoscopic myotomy (DPOEM) for esophageal diverticular disease: a systematic review and meta-analysis.

The traditional way to tackle Zenker's diverticulum (ZD) has been flexible endoscopic septum division (FESD). Recently, the concept of per oral endoscopic myotomy has been found useful for managing diverticular diseases of the esophagus and has been termed DPOEM. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of D-POEM in diverticular disease of the esophagus and to compare it with FESD. We systematically searched PubMed and Embase, for studies reporting clinical success, technical success and adverse events in D-POEM alone or D-POEM comparing with FESD. We computed pooled prevalence for D-POEM alone and risk ratio for D-POEM vs FESD using random effect method with inverse variance approach. Subgroup analysis for ZD, non-ZD and mixed diverticulum was conducted. Totally 19 studies including 341 patients were identified reporting on D-POEM. The pooled clinical, technical success and adverse event rates for D-POEM were 87.07%, 95.19% and 10.22%, respectively. The clinical success was significantly better than FESD while the technical success, adverse event rate, procedure time and length of hospital stay were comparable with FESD. The recurrence rate was negligible for D-POEM compared to FESD. On subgroup analysis by dividing into three groups of ZD, non-ZD and mixed, there was no difference between clinical, technical success and adverse event rate among the three groups. D-POEM is an effective and safe technique among both ZD and non-ZD patients and has better clinical success than FESD.

Phase 1 dose-finding study of metformin in combination with concurrent cisplatin and radiotherapy in patients with locally advanced head and neck squamous cell cancer.

BACKGROUND: The 5-year overall survival (OS) rate remains at 50% for patients with locally advanced head and neck squamous cell carcinoma (LAHNSCC), thereby underscoring the need for improved treatments. An antidiabetic agent, metformin, was found in retrospective studies to improve survival in patients with HNSCC. Therefore, the authors conducted a phase 1 dose escalation study combining metformin with chemoradiotherapy in patients with LAHNSCC. METHODS: Nondiabetic patients with LAHNSCC were enrolled in the current study to receive escalating doses of metformin and CRT based on the modified toxicity probability interval design. Metformin cohort doses included 2000 mg, 2550 mg, and 3000 mg daily in divided doses in addition to cisplatin (at a dose of 100 mg/m2 on days 1, 22, and 43) and standard radiotherapy (70 grays). Adverse events were categorized as per the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.03). RESULTS: Twenty patients were enrolled, 2 of whom withdrew consent. The median age of the patients was 56 years and the majority were male (83%), were white (88%), had p16-positive disease (72%), and were tobacco users (61%). The median length of metformin exposure was 28.5 days. The most common grade ≥3 toxicities were nausea (11%), vomiting (11%), mucositis (6%), acute kidney injury (17%), anemia (6%), and leukopenia (11%). Dose-limiting toxicities included diarrhea and acute kidney injury. After a median follow-up of 19 months, the 2-year overall survival and progression-free survival rates were 90% and 84%, respectively. No hypoglycemia events or lactic acidosis were observed. Cisplatin administration did not appear to affect metformin pharmacokinetics. The maximum tolerated dose for metformin could not be determined given the limited number of patients who tolerated metformin during chemoradiotherapy. CONCLUSIONS: To the authors' knowledge, the current study is the first phase 1 trial combining metformin with chemoradiotherapy. Rates of overall survival and progression-free survival were encouraging in this limited patient population, and warrant further investigation in a phase 2 trial.

An international study on the use of peroral endoscopic myotomy in the management of Zenker's diverticulum.

BACKGROUND AND AIMS: The novel use of peroral endoscopic myotomy (POEM) in the treatment of Zenker's diverticulum (ZD) was recently described in case reports. The aim of this study is to report a multicenter experience with the POEM technique in the management of ZD. METHODS: This is a multicenter international retrospective study involving 10 centers. The Zenker's POEM technique was performed using principles of submucosal endoscopy. RESULTS: Seventy-five patients (73.3 ± 1.2 years, 33 women) were included with a mean Charleson comorbidity index of 4 ± .2. The mean size of ZD was 31.3 ± 1.6 mm (range, 10-89). The overall technical success rate was 97.3% (73/75). There were 2 technical failures because of the inability to locate the septum and failed tunnel creation. Adverse events occurred in 6.7% (5/75): 1 bleed (mild) conservatively managed and 4 perforations (1 severe, 3 moderate). The mean procedure time was 52.4 ± 2.9 minutes, and mean length of hospital stay was 1.8 ± .2 days. Clinical success was achieved in 92% (69/75) with a decrease in mean dysphagia score from 1.96 to .25 (P < .0001). The median length of follow-up was 291.5 days (interquartile range, 103.5-436). At the 12-month follow-up, 1 patient reported symptom recurrence. CONCLUSIONS: Endoscopic management of ZD using the POEM technique is novel and feasible with promising efficacy and safety results. Long-term follow-up is needed to ensure durability of response. In addition, comparative studies with other treatment modalities are warranted.

Multicenter Evaluation of Clinical Efficacy and Safety of Per-oral Endoscopic Myotomy in Children.

OBJECTIVES: Per-oral endoscopic myotomy (POEM) is a recommended treatment modality for achalasia, but there is little published data for its use in children. The objective of the present study was to evaluate whether POEM is clinically effective and safe for children. METHODS: International multicenter retrospective study conducted in 14 tertiary centers that included consecutive children who underwent POEM between January 2012 and August 2018. Outcomes, such as clinical response were assessed whenever available. Adverse events and factors associated with clinical failure were also investigated. RESULTS: A total of 117 patients (mean ±â€ŠSD age: 14.2 ±â€Š3.7 years) underwent POEM for achalasia (type I, n = 36; type II n=66; type III, n=8). Among these, 30 (26%) were pretreated (botulinum injection and/or pneumatic dilatation). Mean ±â€ŠSD baseline Eckardt score was 7.5 ±â€Š2.0. Clinical success was achieved in 90.6% of cases (95%CI [83.8%;95.2%]) in the intention-to-treat analysis. The mean ±â€ŠSD Eckardt score post-POEM was 0.9 ±â€Š1.2 (P < 0.001). The mean duration of follow-up time 545 days (range: 100-1612). A total of 7 adverse events occurred (4 mucosotomies, 2 subcutaneous emphysema, 1 esopleural fistula). Gastroesophageal reflux symptoms were seen in 17 patients (15%); missing data for 10 patients (9%). There was a trend towards more frequent clinical failure in achalasia associated with genetic disorders (40% vs 8%, P = 0.069). CONCLUSIONS: POEM in pediatric patients appears to be effective and safe, although there was a trend towards more frequent clinical failure achalasia associated with genetic disorders. Further studies are needed to assess the long-term outcomes, especially the consequences of GERD.

Acylhydrazones as Antifungal Agents Targeting the Synthesis of Fungal Sphingolipids.

The incidence of invasive fungal infections has risen dramatically in recent decades. Current antifungal drugs are either toxic, likely to interact with other drugs, have a narrow spectrum of activity, or induce fungal resistance. Hence, there is a great need for new antifungals, possibly with novel mechanisms of action. Previously our group reported an acylhydrazone called BHBM that targeted the sphingolipid pathway and showed strong antifungal activity against several fungi. In this study, we screened 19 derivatives of BHBM. Three out of 19 derivatives were highly active against Cryptococcus neoformansin vitro and had low toxicity in mammalian cells. In particular, one of them, called D13, had a high selectivity index and showed better activity in an animal model of cryptococcosis, candidiasis, and pulmonary aspergillosis. D13 also displayed suitable pharmacokinetic properties and was able to pass through the blood-brain barrier. These results suggest that acylhydrazones are promising molecules for the research and development of new antifungal agents.

Retraction notice to "Long-term outcomes of per-oral endoscopic myotomy in patients with achalasia with a minimum follow-up of 2 years: an international multicenter study": [YMGE 85 (2017) 927-933].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted due to overlapping/duplicate material. Data from some patients from this study have previously been published in other journals without cross-referencing. Twenty patients overlap with a paper by Kumbhari et al.1 Thirty-five patients overlap with the study by Ngamruengphong et al.2.

Efficacy and Safety of Peroral Endoscopic Myotomy for Treatment of Achalasia After Failed Heller Myotomy.

BACKGROUND & AIMS: In patients with persistent symptoms after Heller myotomy (HM), treatment options include repeat HM, pneumatic dilation, or peroral endoscopic myotomy (POEM). We evaluated the efficacy and safety of POEM in patients with achalasia with prior HM vs without prior HM. METHODS: We conducted a retrospective cohort study of 180 patients with achalasia who underwent POEM at 13 tertiary centers worldwide, from December 2009 through September 2015. Patients were divided into 2 groups: those with prior HM (HM group, exposure; n = 90) and those without prior HM (non-HM group; n = 90). Clinical response was defined by a decrease in Eckardt scores to 3 or less. Adverse events were graded according to criteria set by the American Society for Gastrointestinal Endoscopy. Technical success, clinical success, and rates of adverse events were compared between groups. Patients were followed up for a median of 8.5 months. RESULTS: POEM was technically successful in 98% of patients in the HM group and in 100% of patients in the non-HM group (P = .49). A significantly lower proportion of patients in the HM group had a clinical response to POEM (81%) than in the non-HM group (94%; P = .01). There were no significant differences in rates of adverse events between the groups (8% in the HM group vs 13% in the non-HM group; P = .23). Symptomatic reflux and reflux esophagitis after POEM were comparable between groups. CONCLUSIONS: POEM is safe and effective for patients with achalasia who were not treated successfully by prior HM. Although the rate of clinical success in patients with prior HM is lower than in those without prior HM, the safety profile of POEM is comparable between groups.

Comprehensive Analysis of Adverse Events Associated With Per Oral Endoscopic Myotomy in 1826 Patients: An International Multicenter Study.

OBJECTIVES: The safety of peroral endoscopic myotomy (POEM) is still debated since comprehensive analysis of adverse events (AEs) associated with the procedure in large multicenter cohort studies has not been performed. To study (1) the prevalence of AEs and (2) factors associated with occurrence of AEs in patients undergoing POEM. METHODS: Patients who underwent POEM at 12 tertiary-care centers between 2009 and 2015 were included in this case-control study. Cases were defined by the occurrence of any AE related to the POEM procedure. Control patients were selected for each AE case by matching for age, gender, and disease classification (achalasia type I and II vs. type III/spastic esophageal disorders). RESULTS: A total of 1,826 patients underwent POEM. Overall, 156 AEs occurred in 137 patients (7.5%). A total of 51 (2.8%) inadvertent mucosotomies occurred. Mild, moderate, and severe AEs had a frequency of 116 (6.4%), 31 (1.7%), and 9 (0.5%), respectively. Multivariate analysis demonstrated that sigmoid-type esophagus (odds ratio (OR) 2.28, P=0.05), endoscopist experience <20 cases (OR 1.98, P=0.04), use of a triangular tip knife (OR 3.22, P=0.05), and use of an electrosurgical current different than spray coagulation (OR 3.09, P=0.02) were significantly associated with the occurrence of AEs. CONCLUSIONS: This large study comprehensively assessed the safety of POEM and highly suggests POEM as a relatively safe procedure when performed by experts at tertiary centers with an overall 7.5% prevalence of AEs. Severe AEs are rare. Sigmoid-type esophagus, endoscopist experience, type of knife, and current used can be considered as predictive factors of AE occurrence.

Long-term outcomes of per-oral endoscopic myotomy in patients with achalasia with a minimum follow-up of 2 years: an international multicenter study.

BACKGROUND AND AIMS: Per-oral endoscopic myotomy (POEM) has shown promising safety and efficacy in short-term studies. However, long-term follow-up data are very limited. The aims of this study were to assess (1) clinical outcome of patients with a minimum post-POEM follow-up of 2 years and (2) factors associated with long-term clinical failure after POEM. METHODS: A retrospective chart review was performed that included all consecutive patients with achalasia who underwent POEM with a minimum follow-up of 2 years at 10 tertiary-care centers. Clinical response was defined by a decrease in Eckardt score to 3 or lower. RESULTS: A total of 205 patients (45.8% men; mean age, 49 years) were followed for a median of 31 months (interquartile range, 26-38 months). Of these, 81 patients (39.5%) had received previous treatment for achalasia before POEM. Clinical success was achieved in 98% (185/189), 98% (142/144), and 91% (187/205) of patients with follow-up within 6 months, at 12 months, and ≥24 months, respectively. Of 185 patients with clinical response at 6 months, 11 (6%) experienced recurrent symptoms at 2 years. History of previous pneumatic dilation was associated with long-term treatment failure (odds ratio, 3.41; 95% confidence interval, 1.25-9.23). Procedure-related adverse events occurred in 8.2% of patients and only 1 patient required surgical intervention. Abnormal esophageal acid exposure and reflux esophagitis were documented in 37.5% and 18% of patients, respectively. However, these rates are simply a reference number among a very selective group of patients. CONCLUSIONS: POEM is safe and provides high initial clinical success and excellent long-term outcomes. Among patients with confirmed clinical response within 6 months, 6% had recurrent symptoms by 2 years.

Evaluation of Vancomycin Use in Late-Onset Neonatal Sepsis Using the Area Under the Concentration-Time Curve to the Minimum Inhibitory Concentration ≥400 Target.

AIM: To develop a vancomycin population pharmacokinetic model and assess the probability of attaining a pharmacodynamic target associated with clinical and microbiological success, a ratio of the 24-hour area under the concentration-time curve to the minimum inhibitory concentration (MIC) ≥ 400, in a 5-year clinical cohort of preterm and term neonatal patients with late-onset staphylococcal sepsis. METHODS: Therapeutic drug monitoring data were obtained from septic neonates with ≥1 vancomycin concentration(s) from January 2006 to September 2011. Only neonates with a postnatal age of >72 hours and a positive microbiological culture were included. Population pharmacokinetic model was developed using nonlinear mixed effects modeling (NONMEM 7.2). Eleven demographic characteristics were evaluated as covariates. Probabilities of achieving the pharmacodynamic target were evaluated. RESULTS: A 1-compartment model with first-order elimination was constructed from 528 vancomycin concentrations collected from 152 preterm and term neonates. Body weight, creatinine clearance (CL), and postmenstrual age were identified as significant covariates. Estimated vancomycin CL and volume of distribution for typical neonates were 0.068 ± 0.03 L·h·kg and 0.62 ± 0.13 L/kg, respectively. Coagulase-negative staphylococci (85.5%) and Staphylococcus aureus (14.5%) were the common pathogenic organisms. The distribution of vancomycin MIC breakpoints was composed of approximately 70% MIC breakpoint of ≤2 mcg/mL. Approximately 54% of neonates, with a median serum creatinine concentration of 0.44 mg/dL, achieved the target ratio of 24-hour area under the concentration-time curve to the MIC ≥ 400 with a median daily dose of 30 (interquartile range, 21-42) mg/kg. CONCLUSIONS: Body weight, creatinine CL, and postmenstrual age significantly influenced vancomycin CL. The current vancomycin doses are acceptable at MICs ≤1 mcg/mL because they are likely to achieve the pharmacodynamic target in the majority of neonatal patients, although higher doses may be considered for more resistant staphylococcal infections.

Safety, tolerability and pharmacokinetics of 2-pyridylacetic acid, a major metabolite of betahistine, in a phase 1 dose escalation study in subjects with ADHD.

Betahistine, a potent histamine H3 receptor antagonist, is being developed for the treatment of attention deficit hyperactivity disorder (ADHD) that manifests with symptoms such as hyperactivity, impulsivity and inattention. This study describes the pharmacokinetics of betahistine in ADHD subjects at doses higher than 50 mg. These assessments were made during a randomized, placebo-controlled, single blind, dose escalation study to determine the safety, tolerability and pharmacokinetics of once daily doses of 50 mg, 100 mg and 200 mg of betahistine in subjects with ADHD. Plasma levels of 2-pyridylacetic acid (2-PAA), a major metabolite of betahistine were quantified using a validated LC-MS/MS method and used for pharmacokinetic analysis and dose proportionality of betahistine. A linear relationship was observed in Cmax and AUC0-4 of 2-PAA with the betahistine dose (R2 0.9989 and 0.9978, respectively) and dose proportionality coefficients (ß) for the power model were 0.8684 (Cmax) and 1.007 (AUC0-4). A population pharmacokinetic model with first-order absorption of betahistine and metabolism to 2-PAA, followed by a first-order elimination of 2-PAA provides estimates of clearance that underscored the linear increase in systemic exposure with dose. There were no serious adverse events reported in the study, betahistine was safe and well tolerated at all the dose levels tested.

A multimodal drug-diet-immunotherapy combination restrains melanoma progression and metastasis.

The genetic landscape of cancer cells can lead to specific metabolic dependencies for tumor growth. Dietary interventions represent an attractive strategy to restrict the availability of key nutrients to tumors. In this study, we identified that growth of a subset of melanoma was severely restricted by a rationally designed combination therapy of a stearoyl-CoA desaturase (SCD) inhibitor with an isocaloric low-oleic acid diet. Despite its importance in oncogenesis, SCD underwent monoallelic co-deletion along with PTEN on chromosome 10q in about 47.5% of melanoma, and the other SCD allele was methylated, resulting in very low SCD expression. While this SCD deficient subset was refractory to SCD inhibitors, the subset of PTEN wildtype melanoma that retained SCD was sensitive. As dietary oleic acid could potentially blunt the effect of SCD inhibitors, a low-oleic acid custom diet was combined with SCD inhibitor. The combination reduced monounsaturated fatty acids and increased saturated fatty acids, inducing robust apoptosis and growth suppression and inhibiting lung metastasis with minimal toxicity in preclinical mouse models of PTEN wildtype melanoma. When combined with anti-PD1 immunotherapy, the SCD inhibitor improved T cell functionality and further constrained melanoma growth in mice. Collectively, these results suggest that optimizing SCD inhibitors with diets low in oleic acid may offer a viable and efficacious therapeutic approach for improving melanoma treatment.

A Phase 0/I Pharmacokinetic and Pharmacodynamics and Safety and Tolerability Study of Letrozole in Combination with Standard Therapy in Recurrent High-Grade Gliomas.

PURPOSE: High-grade gliomas (HGG) carry a poor prognosis, with glioblastoma accounting for almost 50% of primary brain malignancies in the elderly. Unfortunately, despite the use of multiple treatment modalities, the prognosis remains poor in this population. Our preclinical studies suggest that the presence of aromatase expression, encoded by CYP19A1, is significantly upregulated in HGGs. Remarkably, we find that letrozole (LTZ), an FDA-approved aromatase inhibitor, has marked activity against HGGs. PATIENTS AND METHODS: We conducted a phase 0/I single-center clinical trial (NCT03122197) to assess the tumoral availability, pharmacokinetics (PK), safety, and tolerability of LTZ in recurrent patients with HGG. Planned dose cohorts included 2.5, 5, 10, 12.5, 15, 17.5, and 20 mg of LTZ administered daily pre- and postsurgery or biopsy. Tumor samples were assayed for LTZ content and relevant biomarkers. The recommended phase 2 dose (R2PD) was determined as the dose that resulted in predicted steady-state tumoral extracellular fluid (ECF; Css,ecf) >2 µmol/L and did not result in ≥33% dose-limiting adverse events (AE) assessed using CTCAE v5.0. RESULTS: Twenty-one patients were enrolled. Common LTZ-related AEs included fatigue, nausea, musculoskeletal, anxiety, and dysphoric mood. No DLTs were observed. The 15 mg dose achieved a Css,ecf of 3.6 ± 0.59 µmol/L. LTZ caused dose-dependent inhibition of estradiol synthesis and modulated DNA damage pathways in tumor tissues as evident using RNA-sequencing analysis. CONCLUSIONS: On the basis of safety, brain tumoral PK, and mechanistic data, 15 mg daily is identified as the RP2D for future trials.

Solubilization of flurbiprofen into aptamer-modified PEG-PLA micelles for targeted delivery to brain-derived endothelial cells in vitro.

Novel aptamer-functionalized polyethylene glycol-polylactic acid (PEG-PLA) (APP) micelles were developed with the objective to target the transferrin receptor on brain endothelial cells. Flurbiprofen, a potential drug for therapeutic management of Alzheimer's disease (AD), was loaded into the APP micelles using the co-solvent evaporation method. Results indicated that 9.03% (w/w) of flurbiprofen was entrapped in APP with good retention capacity in vitro. Targeting potential of APPs was investigated using the transferring receptor-expressing murine brain endothelial bEND5 cell line. APPs significantly enhanced surface association of micelles to bEND5 cells as quantified by fluorescence spectroscopy. Most importantly, APPs significantly enhanced intracellular flurbiprofen delivery when compared to unmodified micelles. These results suggest that APP micelles may offer an effective strategy to deliver therapeutically effective flurbiprofen concentrations into the brain for AD patients.