Georgina Meneses-Lorente

Effects of High-Density Lipoprotein Elevation With Cholesteryl Ester Transfer Protein Inhibition on Insulin Secretion

Rationale: High-density lipoprotein cholesterol elevation via cholesteryl ester transfer protein (CETP) inhibition represents a novel therapy for atherosclerosis, which also may have relevance for type 2 diabetes mellitus. Objective: The current study assessed the effects of a CETP inhibitor on postprandial insulin, ex vivo insulin secretion, and cholesterol efflux from pancreatic &bgr;-cells. Methods and Results: Healthy participants received a daily dose of CETP inhibitor (n=10) or placebo (n=15) for 14 days in a randomized double-blind study. Insulin secretion and cholesterol efflux from MIN6N8 &bgr;-cells were determined after incubation with treated plasma. CETP inhibition increased plasma high-density lipoprotein cholesterol, apolipoprotein AI, and postprandial insulin. MIN6N8 &bgr;-cells incubated with plasma from CETP inhibitor–treated individuals (compared with placebo) exhibited an increase in both glucose-stimulated insulin secretion and cholesterol efflux over the 14-day treatment period. Conclusions: CETP inhibition increased postprandial insulin and promoted ex vivo &bgr;-cell glucose-stimulated insulin secretion, potentially via enhanced &bgr;-cell cholesterol efflux.Rationale: High-density lipoprotein (HDL) cholesterol elevation via cholesteryl ester transfer protein (CETP) inhibition represents a novel therapy for atherosclerosis, which may also have relevance for type 2 diabetes. Objective: The current study assessed the effects of a CETP inhibitor (CETPi) on postprandial insulin, ex vivo insulin secretion and cholesterol efflux from pancreatic β-cells. Methods and Results: Healthy participants received a daily dose of CETPi (n=10) or placebo (n=15) for 14 days in a randomized, double-blind study. Insulin secretion and cholesterol efflux from MIN6N8 β-cells was determined following incubation with treated plasma. CETP inhibition increased plasma HDL cholesterol, apoAI and postprandial insulin. MIN6N8 β-cells incubated with plasma from CETPi-treated individuals (vs placebo) exhibited an increase in both glucose-stimulated insulin secretion (GSIS) and cholesterol efflux over the 14 day treatment period. Conclusions: CETP inhibition increased postprandial insulin and promoted ex vivo β-cell GSIS, potentially via enhanced β-cell cholesterol efflux.

Effects of HDL Elevation with CETP Inhibition on Insulin Secretion

Rationale: High-density lipoprotein cholesterol elevation via cholesteryl ester transfer protein (CETP) inhibition represents a novel therapy for atherosclerosis, which also may have relevance for type 2 diabetes mellitus. Objective: The current study assessed the effects of a CETP inhibitor on postprandial insulin, ex vivo insulin secretion, and cholesterol efflux from pancreatic &bgr;-cells. Methods and Results: Healthy participants received a daily dose of CETP inhibitor (n=10) or placebo (n=15) for 14 days in a randomized double-blind study. Insulin secretion and cholesterol efflux from MIN6N8 &bgr;-cells were determined after incubation with treated plasma. CETP inhibition increased plasma high-density lipoprotein cholesterol, apolipoprotein AI, and postprandial insulin. MIN6N8 &bgr;-cells incubated with plasma from CETP inhibitor–treated individuals (compared with placebo) exhibited an increase in both glucose-stimulated insulin secretion and cholesterol efflux over the 14-day treatment period. Conclusions: CETP inhibition increased postprandial insulin and promoted ex vivo &bgr;-cell glucose-stimulated insulin secretion, potentially via enhanced &bgr;-cell cholesterol efflux.Rationale: High-density lipoprotein (HDL) cholesterol elevation via cholesteryl ester transfer protein (CETP) inhibition represents a novel therapy for atherosclerosis, which may also have relevance for type 2 diabetes. Objective: The current study assessed the effects of a CETP inhibitor (CETPi) on postprandial insulin, ex vivo insulin secretion and cholesterol efflux from pancreatic β-cells. Methods and Results: Healthy participants received a daily dose of CETPi (n=10) or placebo (n=15) for 14 days in a randomized, double-blind study. Insulin secretion and cholesterol efflux from MIN6N8 β-cells was determined following incubation with treated plasma. CETP inhibition increased plasma HDL cholesterol, apoAI and postprandial insulin. MIN6N8 β-cells incubated with plasma from CETPi-treated individuals (vs placebo) exhibited an increase in both glucose-stimulated insulin secretion (GSIS) and cholesterol efflux over the 14 day treatment period. Conclusions: CETP inhibition increased postprandial insulin and promoted ex vivo β-cell GSIS, potentially via enhanced β-cell cholesterol efflux.

Coadministration of Dalcetrapib With Pravastatin, Rosuvastatin, or Simvastatin: No Clinically Relevant Drug‐Drug Interactions

Dalcetrapib targets cholesteryl ester transfer protein and increases high‐density lipoprotein cholesterol (HDL‐C) levels. It is in clinical development for the prevention of cardiovascular events and will likely be used in combination with standard of care, including statins. Three crossover studies in healthy males investigated the pharmacokinetic drug‐drug interaction potential of 900 mg dalcetrapib and statins: two 3‐period studies (dalcetrapib plus pravastatin or rosuvastatin) and a 2‐period study (dalcetrapib plus simvastatin). Effect on lipids and safety were secondary end points. The 900 mg dose investigated is higher than the 600 mg dose currently being investigated in Phase III. Coadministration of dalcetrapib with pravastatin, rosuvastatin, or simvastatin was not associated with significant increases in statin exposure except for a 26% increase in rosuvastatin Cmax (90% CI 1.088 to 1.468) but not AUC0–24 (90% CI0.931 to 1.085). Dalcetrapib AUC0–24 and Cmax were not significantly altered by coadministration with pravastatin, and were significantly lower when dalcetrapib was coadministered with rosuvastatin or simvastatin compared with dalcetrapib alone. The HDL‐C increase with dalcetrapib was not compromised by coadministration with statins, and reduction in low‐density lipoprotein cholesterol with dalcetrapib coadministered with statins was greater than with statins alone. Dalcetrapib alone and coadministered with statins was generally well tolerated.

First-in-Human Phase I Study of Lumretuzumab, a Glycoengineered Humanized Anti-HER3 Monoclonal Antibody, in Patients with Metastatic or Advanced HER3-Positive Solid Tumors.

Purpose: A first-in-human phase I study was conducted to characterize safety, efficacy, and pharmacokinetic (PK) and pharmacodynamic (PD) properties of lumretuzumab, a humanized and glycoengineered anti-HER3 monoclonal antibody, in patients with advanced cancer. Experimental Design: Twenty-five patients with histologically confirmed HER3-expressing tumors received lumretuzumab (100, 200, 400, 800, 1,600, and 2,000 mg) every two weeks (q2w) in 3+3 dose-escalation phase. In addition, 22 patients were enrolled into an extension cohort at 2,000 mg q2w. Results: There were no dose-limiting toxicities. Common adverse events (any grade) included diarrhea (22 patients, 46.8%), fatigue (21 patients, 44.7%), decreased appetite (15 patients, 31.9%), infusion-related reactions (13 patients, 27.7%), and constipation (10 patients, 21.3%). The peak concentration (Cmax) and area under the concentration–time curve up to the last measurable concentration (AUClast) of lumretuzumab increased more than dose proportionally from 100 mg up to 400 mg. Linear PK was observed with doses ≥400 mg q2w indicating target-mediated drug disposition saturation. Downregulation of HER3 membranous protein was observed in on-treatment tumor biopsies from 200 mg, and was maximal at and above 400 mg. An ex vivo assay demonstrated increased activation potential of peripheral NK lymphocytes with lumretuzumab compared with a non-glycoengineered anti-HER3 antibody. Ten patients (21.3%) had stable disease and remained on study at a median of 111 days (range, 80–225 days). Conclusions: Lumretuzumab was well tolerated and showed evidence of clinical activity. Linear serum PK properties and plateauing of PD effects in serial tumor biopsies indicate optimal biologically active doses of lumretuzumab from 400 mg onwards. Clin Cancer Res; 22(4); 877–85. ©2015 AACR.

Utility of Long-Term Cultured Human Hepatocytes as an in Vitro Model for Cytochrome P450 Induction

Cytochrome P450 (P450) induction may have considerable implications for drug therapy. Therefore, understanding the induction potential of a new chemical entity at an early stage in discovery is crucial to reduce the risk of failure in the clinic and help the identification of noninducing chemical structures. Availability of human viable tissue often limits evaluation of induction potential in human hepatocytes. A solution is to increase the time period during which the hepatocytes remain viable. In this study we have investigated the induction of several P450 isozymes in long-term cultured hepatocytes compared with short-term cultured hepatocytes from the same individuals. Short- and long-term cultured primary hepatocytes isolated from each individual were cultured in a 96-well format and treated for 24 h with a range of prototypical P450 inducers and Merck Research Laboratories compounds. CYP3A4, 1A1, 1A2, 2B6, and 2C9 mRNA levels were measured using quantitative real-time reverse transcriptase-polymerase chain reaction (TaqMan) from the same cultured hepatocyte wells. CYP3A4, 1A1, 1A2, 2B6, and 2C9 were shown to be inducible in long-term cultured hepatocytes. The -fold induction varied between donors, and between short- and long-term cultured hepatocytes from the same donor. However, this variability can be controlled by normalizing data from each hepatocyte preparation to a positive control. The use of long-term cultured hepatocytes on 96-well plates has proven to be sensitive, robust, and convenient for assessing P450 induction potential of new compound entities during the drug discovery process.

No clinically relevant drug–drug interactions when dalcetrapib is co-administered with atorvastatin

Objectives: Dalcetrapib, which targets cholesteryl ester transfer protein, is in clinical development for prevention of cardiovascular events and is likely to be used concomitantly with statins. Two studies investigated co-administration of dalcetrapib with atorvastatin and any effects of the timing of atorvastatin on the pharmacokinetics of dalcetrapib. Research design and methods: Two crossover studies were performed in healthy subjects: a two-period study of dalcetrapib 900 mg concurrently with atorvastatin (concurrent dosing study) and a three-period study of dalcetrapib 600 mg (dose chosen for Phase III) with atorvastatin concurrently or serially 4 h after dalcetrapib (interval dosing study). Main outcome measures: The primary pharmacokinetic end points were AUC0 – 24 and Cmax; lipid effects and tolerability were secondary end points. Results: In the concurrent study (n = 26), co-administration reduced dalcetrapib AUC0 – 24 and Cmax and caused small changes in AUC0 – 24 and Cmax of atorvastatin and its active metabolites. In the interval study (n = 52), serial and concurrent co-administration of atorvastatin resulted in similar reductions in dalcetrapib exposure that were comparable to those observed in the concurrent dosing study. Co-administration did not decrease the efficacy of dalcetrapib or atorvastatin and was generally well tolerated. Conclusions: These results indicate no clinically relevant interactions for co-administration of dalcetrapib with atorvastatin.

Effects of food intake on the pharmacokinetic properties of dalcetrapib: findings from three phase I, single-dose crossover studies in healthy volunteers.

BACKGROUND Preclinical studies have reported that the relative bioavailability of dalcetrapib, a modulator of cholesteryl ester transfer protein (CETP) inhibitor activity, was ∼60% higher when administered in the fed state compared with the fasting state. OBJECTIVE This article reports on 3 studies conducted to assess the effects of food intake, timing of administration with respect to meals, and meal size and content on the relative bioavailability of dalcetrapib in healthy male subjects. METHODS Three Phase I studies were performed in healthy subjects: (1) a 2-period crossover study of a single dose of dalcetrapib 900 mg administered in the fed and fasting states (fed versus fasting study [1999]); (2) a 3-period crossover study of a single dose of dalcetrapib 600 mg administered after a light morning meal, a standard evening meal, and a light evening meal (meal timing/size study [2005]); and (3) a 4-period crossover study of a single dose of dalcetrapib 600 mg administered 30 minutes after a high-fat meal or a standard evening meal, and 30 minutes before or 3 hours after the latter (high-fat meal study [2007]). Blood samples for pharmacokinetic analyses (AUC(0-36) or AUC(0-∞), C(max)) were collected up to 36, 144, and 96 hours after study drug administration in the fed versus fasting, meal timing/size, and high-fat meal studies, respectively. CETP activity was measured using a radioisotopic method in the fed versus fasting study and a fluorometric method in the meal timing/size and high-fat meal studies. Tolerability was assessed using monitoring of adverse events, laboratory parameters, vital signs, and ECG. RESULTS Six men were enrolled in the fed versus fasting study (mean age, 37 years; mean body mass index [BMI], 23.6 kg/m(2)). Dalcetrapib exposure was increased by 64% (AUC(0-36)) and 126% (C(max)) after administration in the fed state. Eighteen men were enrolled in the analysis of the effects of meal timing and size on the properties of dalcetrapib (mean age, 30.5 years; mean BMI, 25.1 kg/m(2)). When dalcetrapib was administered after a light morning or a light evening meal, comparable values were found for mean dalcetrapib AUC(0-∞) (7400 and 7860 ng·h/mL, respectively) and C(max) (589 and 552 ng/mL), whereas administration after a standard evening meal was associated with increased AUC(0-∞) (14.3%-14.7%) and C(max) (25.5%-35.3%). Forty-nine men were included in the analysis in the high-fat meal study (mean age, 32.3 years; mean BMI, 23.9 kg/m(2)). Compared with administration after a standard evening meal, administration after a high-fat evening meal was associated with increased AUC(0-∞) (34.9%) and C(max) (43.7%). Between-treatment differences in exposure within each study also were reflected in apparent differences in CETP activity. All treatments were generally well tolerated. CONCLUSIONS Dalcetrapib exposure was increased in the fed state and, to a lesser extent, was dependent on the size and fat content of the meal. Exposure was independent of dosing time. Dalcetrapib was generally well tolerated.

Phase Ib study of lumretuzumab plus cetuximab or erlotinib in solid tumor patients and evaluation of HER3 and heregulin as potential biomarkers of clinical activity

Purpose: This study investigated the safety, clinical activity, and target-associated biomarkers of lumretuzumab, a humanized, glycoengineered, anti-HER3 monoclonal antibody (mAb), in combination with the EGFR-blocking agents erlotinib or cetuximab in patients with advanced HER3-positive carcinomas. Experimental Design: The study included two parts: dose escalation and dose extension phases with lumretuzumab in combination with either cetuximab or erlotinib, respectively. In both parts, patients received lumretuzumab doses from 400 to 2,000 mg plus cetuximab or erlotinib according to standard posology, respectively. The effect of HRG mRNA and HER3 mRNA and protein expression were investigated in a dedicated extension cohort of squamous non–small cell lung cancer (sqNSCLC) patients treated with lumretuzumab and erlotinib. Results: Altogether, 120 patients were treated. One dose-limiting toxicity (DLT) in the cetuximab part and two DLTs in the erlotinib part were reported. The most frequent adverse events were gastrointestinal and skin toxicities, which were manageable. The objective response rate (ORR) was 6.1% in the cetuximab part and 4.2% in the erlotinib part. In the sqNSCLC extension cohort of the erlotinib part, higher tumor HRG and HER3 mRNA levels were associated with a numerically higher disease control rate but not ORR. Conclusions: The toxicity profile of lumretuzumab in combination with cetuximab and erlotinib was manageable, but only modest clinical activity was observed across tumor types. In the sqNSCLC cohort, there was no evidence of meaningful clinical benefit despite enriching for tumors with higher HRG mRNA expression levels. Clin Cancer Res; 23(18); 5406–15. ©2017 AACR.

Zr-89-Lumretuzumab PET Imaging before and during HER3 Antibody Lumretuzumab Treatment in Patients with Solid Tumors

Purpose: We evaluated biodistribution and tumor targeting of 89Zr-lumretuzumab before and during treatment with lumretuzumab, a human epidermal growth factor receptor 3 (HER3)–targeting monoclonal antibody. Experimental Design: Twenty patients with histologically confirmed HER3-expressing tumors received 89Zr-lumretuzumab and underwent positron emission tomography (PET). In part A, 89Zr-lumretuzumab was given with additional, escalating doses of unlabeled lumretuzumab, and scans were performed 2, 4, and 7 days after injection to determine optimal imaging conditions. In part B, patients were scanned following tracer injection before (baseline) and after a pharmacodynamic (PD)-active lumretuzumab dose for saturation analysis. HER3 expression was determined immunohistochemically in skin biopsies. Tracer uptake was calculated as standardized uptake value (SUV). Results: Optimal PET conditions were found to be 4 and 7 days after administration of 89Zr-lumretuzumab with 100-mg unlabeled lumretuzumab. At baseline using 100-mg unlabeled lumretuzumab, the tumor SUVmax was 3.4 (±1.9) at 4 days after injection. SUVmean values for normal blood, liver, lung, and brain tissues were 4.9, 6.4, 0.9 and 0.2, respectively. Saturation analysis (n = 7) showed that 4 days after lumretuzumab administration, tumor uptake decreased by 11.9% (±8.2), 10.0% (±16.5), and 24.6% (±20.9) at PD-active doses of 400, 800, and 1,600 mg, respectively, when compared with baseline. Membranous HER3 was completely downregulated in paired skin biopsies already at and above 400-mg lumretuzumab. Conclusions: PET imaging showed biodistribution and tumor-specific 89Zr-lumretuzumab uptake. Although, PD-active lumretuzumab doses decreased 89Zr-lumretuzumab uptake, there was no clear evidence of tumor saturation by PET imaging as the tumor SUV did not plateau with increasing doses. Clin Cancer Res; 23(20); 6128–37. ©2017 AACR.

Phase I trial of capecitabine rapidly disintegrating tablets and concomitant radiation therapy in children with newly diagnosed brainstem gliomas and high-grade gliomas

BACKGROUND We conducted a phase I study to estimate the maximum tolerated dose and describe the dose-limiting toxicities and pharmacokinetics of oral capecitabine rapidly disintegrating tablets given concurrently with radiation therapy to children with newly diagnosed brainstem or high-grade gliomas. METHODS Children 3-21 y with newly diagnosed intrinsic brainstem or high-grade gliomas were eligible for enrollment. The starting dose was 500 mg/m(2), given twice daily, with subsequent cohorts enrolled at 650 mg/m(2) and 850 mg/m(2) using a 3 + 3 phase I design. Children received capecitabine at the assigned dose daily for 9 wks starting from the first day of radiation therapy (RT). Following a 2-wk break, patients received 3 courses of capecitabine 1250 mg/m(2) twice daily for 14 days followed by a 7-day rest. Pharmacokinetic sampling was performed in consenting patients. Six additional patients with intrinsic brainstem gliomas were enrolled at the maximum tolerated dose to further characterize the pharmacokinetic and toxicity profiles. RESULTS Twenty-four patients were enrolled. Twenty were fully assessable for toxicity. Dose-limiting toxicities were palmar plantar erythroderma (grades 2 and 3) and elevation of alanine aminotransferase (grades 2 and 3). Systemic exposure to capecitabine and metabolites was similar to or slightly lower than predicted based on adult data. CONCLUSIONS Capecitabine with concurrent RT was generally well tolerated. The recommended phase II capecitabine dose when given with concurrent RT is 650 mg/m(2), administered twice daily. A phase II study to evaluate the efficacy of this regimen in children with intrinsic brainstem gliomas is in progress (PBTC-030).