Population pharmacokinetics and exposure-response analyses of safety (ARIA-E and isolated ARIA-H) of lecanemab in subjects with early Alzheimer's disease.

Lecanemab (Leqembi®) was recently approved by health authorities in the United States, Japan, and China to treat early Alzheimer's disease (AD), including patients with mild cognitive impairment (MCI) or mild dementia due to Alzheimer's disease upon confirmation of amyloid beta pathology. Extensively and sparsely sampled PK profiles from 1619 AD subjects and 21,929 serum lecanemab observations from two phase I, one phase II, and one phase III studies were well characterized using a two-compartment model with first-order elimination. The final PK model quantified covariate effects of body weight and sex on clearance and central volume of distribution, ADA-positive status, and albumin on clearance, and of Japanese ethnicity on central and peripheral volumes of distribution. Exposure to lecanemab was comparable between two lecanemab-manufacturing processes. However, none of the identified covariates in the model had a clinically relevant impact on model-predicted lecanemab Cmax or AUC at steady state following 10 mg/kg bi-weekly. Importantly, age, a well-recognized risk factor for AD, was not found to significantly affect lecanemab PK. The incidence of ARIA-E as a function of lecanemab exposure was modeled using a logit function with data pooled from 2641 subjects from the phase II and phase III studies, in which a total of 177 incidences of ARIA-E were observed. The probability of ARIA-E was significantly correlated with model-predicted Cmax and predicted to be higher in subjects homozygous for APOE4. The incidence of isolated ARIA-H was not associated with lecanemab exposure and was similar between placebo and lecanemab-treated subjects.

Population pharmacokinetic-pharmacodynamic modeling of serum biomarkers as predictors of tumor dynamics following lenvatinib treatment in patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC).

Lenvatinib is a receptor tyrosine kinase (RTK) inhibitor targeting vascular endothelial growth factor (VEGF) receptors 1-3, fibroblast growth factor (FGF) receptors 1-4, platelet-derived growth factor receptor-α (PDGFRα), KIT, and RET that have been implicated in pathogenic angiogenesis, tumor growth, and cancer. The primary objective of this work was to evaluate, by establishing quantitative relationships, whether lenvatinib exposure and longitudinal serum biomarker data (VEGF, Ang-2, Tie-2, and FGF-23) are predictors for change in longitudinal tumor size which was assessed based on data from 558 patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC) receiving either lenvatinib or placebo treatment. Lenvatinib PK was best described by a 3-compartment model with simultaneous first- and zero-order absorption and linear elimination from the central compartment with significant covariates (body weight, albumin <30 g/dL, ALP>ULN, RR-DTC, RCC, HCC subjects, and concomitant CYP3A inhibitors). Except for body weight, none of the covariates have any clinically meaningful effect on exposure to lenvatinib. Longitudinal biomarker measurements over time were reasonably well defined by a PK/PD model with common EC50, Emax, and a slope for disease progression for all biomarkers. Longitudinal tumor measurements over time were reasonably well defined by a tumor growth inhibition Emax model, which in addition to lenvatinib exposure, included model-predicted relative changes from baseline over time for Tie-2 and Ang-2 as having significant association with tumor response. The developed PK/PD models pave the way for dose optimization and potential prediction of clinical response.

Population pharmacokinetic-pharmacodynamic analyses of amyloid positron emission tomography and plasma biomarkers for lecanemab in subjects with early Alzheimer's disease.

Lecanemab is a humanized immunoglobulin G1 monoclonal antibody that selectively binds to soluble Aß aggregate species, while demonstrating low affinity for Aß monomer. This article describes the population pharmacokinetic (PK) and PK/pharmacodynamic (PD) analyses for amyloid plaques, as measured using positron emission tomography (PET), and biomarkers of amyloid pathology as evidenced by Aß42/40 ratio and plasma p-tau181 following i.v. administration of lecanemab in subjects with early Alzheimer's disease. Lecanemab PKs were well-characterized with a two-compartment model with first-order elimination. Final PK model contained covariate effects of anti-drug antibody positive status, sex, body weight, and albumin on clearance. The time course of amyloid PET standard uptake ratio (SUVr), plasma Aß42/40 ratio, and p-tau181 were described using indirect response models with lecanemab exposure as a maximum effect function stimulating the reduction of SUVr, and as a linear function increasing Aß42/40 ratio and decreasing p-tau181 formation rates. PK/PD simulations show that 10 mg/kg biweekly dosing results in larger and faster decrease in SUVr and p-tau181 and increase in Aß42/40 ratio as compared to 10 mg/kg monthly dose. Furthermore, the PK/PD simulations showed that after treatment discontinuation the brain amyloid re-accumulation to baseline levels is slow with a recovery half-life of ~4 years, whereas plasma Aß42/40 ratio and p-tau181 return to baseline levels faster than amyloid. Given the relationship between changes in amyloid PET SUVr and soluble biomarkers, the developed PK/PD models can be used to inform lecanemab dose regimens in future clinical studies.

Lenvatinib dose, efficacy, and safety in the treatment of multiple malignancies.

INTRODUCTION: Lenvatinib is an oral multitargeted tyrosine kinase inhibitor that has shown efficacy and manageable safety across multiple cancer types. The recommended starting doses for lenvatinib differ across cancer types and indications based on whether it is used as monotherapy or as combination therapy. AREAS COVERED: This review covers clinical trials that established the dosing paradigm and efficacy of lenvatinib and defined its adverse-event profile as a monotherapy; or in combination with the mTOR inhibitor, everolimus; or the anti-PD-1 antibody, pembrolizumab; and/or chemotherapy. EXPERT OPINION: Lenvatinib has been established as standard-of-care either as a monotherapy or in combination with other anticancer agents for the treatment of radioiodine-refractory differentiated thyroid carcinoma, hepatocellular carcinoma, renal cell carcinoma, and endometrial carcinoma, and is being investigated further across several other tumor types. The dosing and adverse-event management strategies for lenvatinib have been developed through extensive clinical trial experience. Collectively, the data provide the rationale to start lenvatinib at the recommended doses and then interrupt or dose reduce as necessary to achieve required dose intensity for maximized patient benefit. The adverse-event profile of lenvatinib is consistent with that of other tyrosine kinase inhibitors, and clinicians are encouraged to review and adopt relevant symptom-management strategies.

Safety and efficacy of lenvatinib by starting dose based on body weight in patients with unresectable hepatocellular carcinoma in REFLECT.

BACKGROUND: REFLECT was an open-label, phase 3 study comparing the efficacy and safety of lenvatinib versus sorafenib in patients with unresectable hepatocellular carcinoma (uHCC). Based on phase 2 study (Study 202) results, body weight-based dosing for lenvatinib was used in REFLECT to minimize dose disruptions and modifications needed to address dose-related adverse events. This post hoc analysis of REFLECT data assessed lenvatinib efficacy and safety by body weight group. METHODS: The study randomly administered lenvatinib (n = 476) or sorafenib (n = 475) to patients with untreated (no prior systemic therapy) uHCC. Lenvatinib starting-dose data were stratified by body weight: patients weighing < 60 kg received 8 mg/day; patients weighing ≥ 60 kg received 12 mg/day. Overall survival (OS), progression-free survival (PFS), objective response rate, and safety were assessed. RESULTS: Survival outcomes and safety profiles appeared similar between the two body-weight-based lenvatinib starting-dose groups. Median OS for patients in the < 60 kg body weight group (n = 153) was 13.4 months [95% confidence interval (CI) 10.5-15.7] compared to 13.7 months (95% CI 12.0-15.6) in the ≥ 60 kg body weight group (n = 325). In both lenvatinib groups, PFS was 7.4 months (< 60 kg group: 95% CI 5.4-9.2; ≥ 60 kg group: 95% CI 6.9-9.0). Treatment-emergent adverse events (TEAEs) required dose modifications in 43.0% in the < 60 kg body weight group and 57.5% in the ≥ 60 kg body weight group. CONCLUSIONS: This exploratory analysis of data from REFLECT indicated that body weight-based lenvatinib dosing in patients with uHCC was successful in maintaining efficacy, with comparable rates of TEAEs and dose modifications in the two body weight groups. CLININCAL TRIAL: Trial registration ID: ClinicalTrials.gov # NCT01761266.

Exposure-response analysis and simulation of lenvatinib safety and efficacy in patients with radioiodine-refractory differentiated thyroid cancer.

PURPOSE: Once-daily lenvatinib 24 mg is the approved dose for radioiodine-refractory differentiated thyroid cancer. In a phase 3 trial with lenvatinib, the starting dose of 24 mg was associated with a relatively high incidence of adverse events that required dose reductions. We used an exposure-response model to investigate the risk-benefit of different dosing regimens for lenvatinib. METHODS: A population pharmacokinetics/pharmacodynamics modeling analysis was used to simulate the potential benefit of lower starting doses to retain efficacy with improved safety. The seven lenvatinib regimens tested were: 24 mg; and 20 mg, 18 mg, and 14 mg, all with or without up-titration to 24 mg. Exposure-response models for efficacy and safety were created using a 24-week time course. RESULTS: The approved dose of lenvatinib at 24 mg, predicted the best efficacy. However, the lenvatinib dosing regimens of 14 mg with up-titration or 18 mg without up-titration potentially provides comparable efficacy (objective response rate at 24 weeks) and a better safety profile. CONCLUSIONS: Treatment with lenvatinib at starting doses lower than the approved once-daily 24 mg dose could provide comparable antitumor efficacy and a similar or better safety profile. Based on the results from this modeling and simulation study, a comparator dose of lenvatinib 18 mg without up-titration was selected for evaluation in a clinical trial.

Dose Finding of Lenvatinib in Subjects With Advanced Hepatocellular Carcinoma Based on Population Pharmacokinetic and Exposure-Response Analyses.

Hepatocellular carcinoma (HCC) accounts for up to 90% of primary liver cancer occurrences worldwide. Lenvatinib, a multikinase inhibitor, was approved in radioiodine-refractory differentiated thyroid cancer. In this phase 2 study (study 202), we aimed to identify the lenvatinib optimal dose for subjects with advanced HCC Child-Pugh class A. Pooled data from phase 1 studies in healthy adults and in subjects with mixed tumor types, and from study 202 in subjects with HCC, were analyzed using a population pharmacokinetic approach. The relationship between treatment-emergent adverse events leading to withdrawal or dose reduction during cycle 1 and lenvatinib exposure was explored by logistic regression analysis. A receiver operating characteristics analysis was used to investigate the best cutoff values of lenvatinib exposure and body weight to identify a high-risk group for early dose modification. The final pharmacokinetic model included body-weight effects on apparent clearance and volume. The relationship between the lenvatinib area under the plasma concentration-time curve (AUC) at steady state and body weight demonstrated an increase in AUC as body weight decreased in subjects with HCC. An exposure-response relationship was observed, with higher lenvatinib AUC and lower body weight resulting in earlier drug withdrawal or dose reduction. The best cutoff values for body weight and lenvatinib AUC were 57.8 kg and 2430 ng·h/mL, respectively, to predict the group at high risk for early drug withdrawal or dose reduction. We therefore recommend 12-mg and 8-mg starting doses for subjects ≥60 kg and <60 kg, respectively, in subjects with HCC Child-Pugh class A.

Clinical Pharmacokinetic and Pharmacodynamic Profile of Lenvatinib, an Orally Active, Small-Molecule, Multitargeted Tyrosine Kinase Inhibitor.

Lenvatinib is a multikinase inhibitor that targets vascular endothelial growth factor (VEGF) receptors 1-3, fibroblast growth factor receptors 1-4, platelet-derived growth factor receptor-alpha, and RET and KIT proto-oncogenes. Lenvatinib is approved for the treatment of radioiodine-refractory differentiated thyroid cancer in the United States (US), European Union (EU), Canada, Japan, and Switzerland. It is also approved in combination with everolimus for the treatment of advanced renal cell carcinoma following ≥1 VEGF-targeted treatment in the US and EU. In addition, lenvatinib is under investigation for the treatment of hepatocellular carcinoma. As lenvatinib becomes more widely available, a better understanding of its pharmacokinetic profile has become increasingly important. Following oral administration, lenvatinib is absorbed rapidly and is metabolized extensively prior to excretion. This metabolism is mediated by multiple pathways, and several metabolites of lenvatinib have been identified. The effect of food intake on lenvatinib exposure has also been studied and was found to not significantly influence overall exposure to the drug. Exposure to lenvatinib is increased in patients with severe hepatic impairment, indicating that dose reduction must be considered for those patients. The findings summarized here indicate that the clinical pharmacokinetic and pharmacodynamic profile for lenvatinib are predictable, with a dose-independent absorption and elimination profile that supports once-daily administration, and has minimal effects due to mild or moderate renal or hepatic impairment or drug interactions.

Phase 2 study of lenvatinib in patients with advanced hepatocellular carcinoma.

BACKGROUND: Lenvatinib is an oral inhibitor of vascular endothelial growth factor receptor 1-3, fibroblast growth factor receptor 1-4, platelet-derived growth factor receptor alpha, RET, and KIT. This phase 2, single-arm, open-label multicenter study evaluated lenvatinib in advanced hepatocellular carcinoma (HCC). METHODS: Patients with histologically/clinically confirmed advanced HCC who did not qualify for surgical resection or local therapies received lenvatinib at a dosage of 12 mg once daily (QD) in 28-day cycles. The primary efficacy endpoint was time to progression (TTP) per modified Response Evaluation Criteria in Solid Tumors v1.1; secondary efficacy endpoints included objective response rate (ORR), disease control rate (DCR), and overall survival (OS). RESULTS: Between July 2010 and June 2011, 46 patients received lenvatinib at sites across Japan and Korea. The median TTP, as determined by independent radiological review, was 7.4 months [95 % confidence interval (CI): 5.5-9.4]. Seventeen patients (37 %) had partial response and 19 patients (41 %) had stable disease (ORR: 37 %; DCR: 78 %). Median OS was 18.7 months (95 % CI: 12.7-25.1). The most common any-grade adverse events (AEs) were hypertension (76 %), palmar-plantar erythrodysesthesia syndrome (65 %), decreased appetite (61 %), and proteinuria (61 %). Dose reductions and discontinuations due to AEs occurred in 34 (74 %) and 10 patients (22 %), respectively. Median body weight was lower in patients with an early (<30 days) dose withdrawal or reduction than in those without. CONCLUSIONS: Lenvatinib 12-mg QD showed clinical activity and acceptable toxicity profiles in patients with advanced HCC, but early dose modification was necessary in patients with lower body weight. Further development of lenvatinib in HCC should consider dose modification by body weight. TRIAL REGISTRATION ID: www.ClinicalTrials.gov NCT00946153.

Safety and Pharmacokinetics of Lenvatinib in Patients with Advanced Hepatocellular Carcinoma.

PURPOSE: To determine the maximum tolerable dose (MTD), safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of lenvatinib in patients with advanced hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: This multicenter, open-label, phase I, dose-escalation study included patients aged 20 to 80 years, refractory to standard therapy, and stratified by hepatic function measured using Child-Pugh (CP) scores: CP-A (score, 5-6) and CP-B (score, 7-8). Lenvatinib was administered continually once daily for 4-week cycles. MTD was defined as the maximum dose associated with ≤ 1 dose-limiting toxicity (DLT) occurring in cycle 1 among 6 patients. RESULTS: In total, 20 patients (9 in CP-A and 11 in CP-B) were enrolled. The MTD was 12 and 8 mg once daily in CP-A and CP-B, respectively; DLTs included proteinuria, hepatic encephalopathy, and hyperbilirubinemia. The most common grade 3 toxicities included hypertension in CP-A and hyperbilirubinemia in CP-B. Lenvatinib plasma concentration at 24 hours after administration (C24 h) for 12 mg once daily was higher in patients with HCC than in patients with other solid tumors shown in a previous phase I study, but C24 h for 25 mg once daily lenvatinib was comparable. After lenvatinib treatment, the number of circulating endothelial and c-Kit(+) cells decreased and the levels of interleukin (IL)-6, IL10, granulocyte-colony stimulating factor, and vascular endothelial growth factor increased (P < 0.05). Partial responses were observed in 3 patients and tumor shrinkage occurred in 14 patients. CONCLUSIONS: Lenvatinib (12 mg once daily) demonstrated preliminary efficacy with manageable toxicity and is the recommended dose for phase II studies in patients with HCC and CP-A.

Subgroup analysis of Japanese patients in a phase 3 study of lenvatinib in radioiodine-refractory differentiated thyroid cancer.

Lenvatinib significantly prolonged progression-free survival (PFS) versus placebo in patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC) in the phase 3 Study of (E7080) Lenvatinib in Differentiated Cancer of the Thyroid (SELECT) trial. This subanalysis evaluated the efficacy and safety of lenvatinib in Japanese patients who participated in SELECT. Outcomes for Japanese patients (lenvatinib, n = 30; placebo, n = 10) were assessed in relationship to the SELECT population (lenvatinib, n = 261; placebo, n = 131). The primary endpoint was PFS; secondary endpoints included overall survival, overall response rate, and safety. Lenvatinib PFS benefit was shown in Japanese patients (median PFS: lenvatinib, 16.5 months; placebo, 3.7 months), although significance was not reached, presumably due to sample size (hazard ratio, 0.39; 95% confidence interval, 0.10-1.57; P = 0.067). Overall response rates were 63.3% and 0% for lenvatinib and placebo, respectively. No significant difference was found in overall survival. The lenvatinib safety profile was similar between the Japanese and overall SELECT population, except for higher incidences of hypertension (any grade: Japanese, 87%; overall, 68%; grade ≥3: Japanese, 80%; overall, 42%), palmar-plantar erythrodysesthesia syndrome (any grade: Japanese, 70%; overall, 32%; grade ≥3: Japanese, 3%; overall, 3%), and proteinuria (any grade: Japanese, 63%; overall, 31%; grade ≥3: Japanese, 20%; overall, 10%). Japanese patients had more dose reductions (Japanese, 90%; overall, 67.8%), but fewer discontinuations due to adverse events (Japanese, 3.3%; overall, 14.2%). There was no difference in lenvatinib exposure between the Japanese and overall SELECT populations after adjusting for body weight. In Japanese patients with radioiodine-refractory differentiated thyroid cancer, lenvatinib showed similar clinical outcomes to the overall SELECT population. Some differences in adverse event frequencies and dose modifications were observed. Clinical trial registration no.: NCT01321554.

Dose-response relationships of rabeprazole 5, 10, 20, and 40 mg once daily on suppression of gastric acid secretion through the night in healthy Japanese individuals with different CYP2C19 genotypes.

PURPOSE: This study was designed to investigate the antisecretory activity of rabeprazole administered once daily in doses of 5, 10, 20, and 40 mg and different cytochrome P450 2C19 (CYP2C19) genotypes on gastric pH in healthy individuals. Additional objectives were delineating the nighttime from the daytime effect and determining the relationships between the pharmacokinetics and pharmacodynamics of rabeprazole. METHODS: Eight individuals of each of the three genotypes of CYP2C19-homozygous extensive metabolizers (homo-EMs), heterozygous EMs (hetero-EMs), and poor metabolizers (PMs)-were recruited. Twenty-four individuals received a once-daily dose, with dosing interval 24 h of 5, 10, 20, or 40 mg rabeprazole for 5 days in a 4-period crossover fashion. Twenty-four-hour intragastric pH and plasma rabeprazole concentrations were determined on day 5. RESULTS: A dose-dependent increase in median pH and in pH 4 holding time was observed across all CYP2C19 genotypes. When rabeprazole was increased from 20 mg to 40 mg, the differences and 95% confidence intervals (CIs) of nighttime pH 4 holding time between 40 mg and 20 mg in homo-EMs, hetero-EMs, and PMs were 8.0% (-5.0% -21.0%), 28.7% (15.7% -41.6%), and 16.9% (3.9% -29.9%), respectively. The relationship between the area under the plasma concentration-time curve up to the last time point at which rabeprazole was quantifiable (AUC(0-t)) and the pH 4 holding time could be described using a sigmoid maximum effect (E(max)) model. CONCLUSIONS: Our data demonstrate that increasing rabeprazole dose up to 40 mg once daily results in an increasing pharmacodynamic effect, which is most apparent for the control of nocturnal gastric acid secretion.

Pharmacokinetic and pharmacodynamic profiling of cefepime in plasma and peritoneal fluid of abdominal surgery patients.

This study was conducted to characterise the pharmacokinetics and pharmacodynamics of cefepime in plasma and peritoneal fluid (PF). One gram of cefepime was administered to eight laparotomy patients and plasma and PF samples were collected at the end of 0.5 h infusion and every hour for 6 h. Drug concentrations were determined, analysed by population pharmacokinetic modelling and used for a Monte Carlo simulation with minimum inhibitory concentration (MIC) data. The maximum concentration in PF was two-thirds of the value in plasma; however, the concentrations were higher in PF than in plasma at 0.68 h post dose. The probabilities of attaining the pharmacodynamic target (65% of the time above the MIC) were 92-99% in plasma (90% fraction unbound) and 93-100% in PF against Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae with a regimen of 1 g every 12 h. However, 1 g every 8 h or 2 g every 12 h was required for values of 94-95% in plasma and 95-96% in PF against Pseudomonas aeruginosa. These results demonstrate that the pharmacodynamic exposures in PF were almost identical to those estimated from plasma data and provided a pharmacokinetic/pharmacodynamic rationale for the dosing regimen for surgical intra-abdominal infections.

Pharmacokinetic and pharmacodynamic properties of lafutidine after postprandial oral administration in healthy subjects: comparison with famotidine.

Lafutidine, a histamine H(2)-receptor antagonist, inhibits gastric acid secretion during the daytime, however, the relationship between the plasma concentration and the drug response remains unclear. The aim of this study was to compare the pharmacokinetic and pharmacodynamic properties of lafutidine and famotidine following postprandial oral administration. After a lafutidine tablet (10 mg), famotidine tablet (20 mg), or water only (control) was administered, blood samples were taken and intragastric pH was measured. The plasma concentrations of lafutidine and famotidine were determined by HPLC, and the median intragastric pH values per 30 min were used as the degrees of gastric acid suppression. Data were analyzed based on a one-compartment pharmacokinetic model and a sigmoid E(max) pharmacodynamic model. Lafutidine plasma concentrations rapidly increased after administration; famotidine required some time to increase the plasma concentrations, requiring an absorption lag time in the pharmacokinetic model. Between the plasma concentration and DeltapH (the difference in intragastric pH by the drug vs. control), lafutidine showed an anticlockwise hysteresis loop which indicated equilibration delay between the plasma concentration and effect site, requiring an effect site compartment in the pharmacodynamic model; famotidine showed more parallel relationship. These results indicated that the pharmacokinetic and pharmacodynamic properties of lafutidine after postprandial oral administration were different from those of famotidine at least 4.5 h after dosing.