Lecanemab in Early Alzheimer's Disease.

BACKGROUND: The accumulation of soluble and insoluble aggregated amyloid-beta (Aß) may initiate or potentiate pathologic processes in Alzheimer's disease. Lecanemab, a humanized IgG1 monoclonal antibody that binds with high affinity to Aß soluble protofibrils, is being tested in persons with early Alzheimer's disease. METHODS: We conducted an 18-month, multicenter, double-blind, phase 3 trial involving persons 50 to 90 years of age with early Alzheimer's disease (mild cognitive impairment or mild dementia due to Alzheimer's disease) with evidence of amyloid on positron-emission tomography (PET) or by cerebrospinal fluid testing. Participants were randomly assigned in a 1:1 ratio to receive intravenous lecanemab (10 mg per kilogram of body weight every 2 weeks) or placebo. The primary end point was the change from baseline at 18 months in the score on the Clinical Dementia Rating-Sum of Boxes (CDR-SB; range, 0 to 18, with higher scores indicating greater impairment). Key secondary end points were the change in amyloid burden on PET, the score on the 14-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog14; range, 0 to 90; higher scores indicate greater impairment), the Alzheimer's Disease Composite Score (ADCOMS; range, 0 to 1.97; higher scores indicate greater impairment), and the score on the Alzheimer's Disease Cooperative Study-Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS-MCI-ADL; range, 0 to 53; lower scores indicate greater impairment). RESULTS: A total of 1795 participants were enrolled, with 898 assigned to receive lecanemab and 897 to receive placebo. The mean CDR-SB score at baseline was approximately 3.2 in both groups. The adjusted least-squares mean change from baseline at 18 months was 1.21 with lecanemab and 1.66 with placebo (difference, -0.45; 95% confidence interval [CI], -0.67 to -0.23; P<0.001). In a substudy involving 698 participants, there were greater reductions in brain amyloid burden with lecanemab than with placebo (difference, -59.1 centiloids; 95% CI, -62.6 to -55.6). Other mean differences between the two groups in the change from baseline favoring lecanemab were as follows: for the ADAS-cog14 score, -1.44 (95% CI, -2.27 to -0.61; P<0.001); for the ADCOMS, -0.050 (95% CI, -0.074 to -0.027; P<0.001); and for the ADCS-MCI-ADL score, 2.0 (95% CI, 1.2 to 2.8; P<0.001). Lecanemab resulted in infusion-related reactions in 26.4% of the participants and amyloid-related imaging abnormalities with edema or effusions in 12.6%. CONCLUSIONS: Lecanemab reduced markers of amyloid in early Alzheimer's disease and resulted in moderately less decline on measures of cognition and function than placebo at 18 months but was associated with adverse events. Longer trials are warranted to determine the efficacy and safety of lecanemab in early Alzheimer's disease. (Funded by Eisai and Biogen; Clarity AD ClinicalTrials.gov number, NCT03887455.).

Change in Cerebrospinal Fluid Tau Microtubule Binding Region Detects Symptom Onset, Cognitive Decline, Tangles, and Atrophy in Dominantly Inherited Alzheimer's Disease.

OBJECTIVE: Identifying cerebrospinal fluid measures of the microtubule binding region of tau (MTBR-tau) species that reflect tau aggregation could provide fluid biomarkers that track Alzheimer's disease related neurofibrillary tau pathological changes. We examined the cerebrospinal fluid (CSF) MTBR-tau species in dominantly inherited Alzheimer's disease (DIAD) mutation carriers to assess the association with Alzheimer's disease (AD) biomarkers and clinical symptoms. METHODS: Cross-sectional and longitudinal CSF from 229 DIAD mutation carriers and 130 mutation non-carriers had sequential characterization of N-terminal/mid-domain phosphorylated tau (p-tau) followed by MTBR-tau species and tau positron emission tomography (tau PET), other soluble tau and amyloid biomarkers, comprehensive clinical and cognitive assessments, and brain magnetic resonance imaging of atrophy. RESULTS: CSF MTBR-tau species located within the putative "border" region and one species corresponding to the "core" region of aggregates in neurofibrillary tangles (NFTs) increased during the presymptomatic stage and decreased during the symptomatic stage. The "border" MTBR-tau species were associated with amyloid pathology and CSF p-tau; whereas the "core" MTBR-tau species were associated stronger with tau PET and CSF measures of neurodegeneration. The ratio of the border to the core species provided a continuous measure of increasing amounts that tracked clinical progression and NFTs. INTERPRETATION: Changes in CSF soluble MTBR-tau species preceded the onset of dementia, tau tangle increase, and atrophy in DIAD. The ratio of 4R-specific MTBR-tau (border) to the NFT (core) MTBR-tau species corresponds to the pathology of NFTs in DIAD and change with disease progression. The dynamics between different MTBR-tau species in the CSF may serve as a marker of tau-related disease progression and target engagement of anti-tau therapeutics. ANN NEUROL 2023;93:1158-1172.

Plasma pTau217 predicts continuous brain amyloid levels in preclinical and early Alzheimer's disease.

BACKGROUND: This study investigated the potential of phosphorylated plasma Tau217 ratio (pTau217R) and plasma amyloid beta (Aß) 42/Aß40 in predicting brain amyloid levels measured by positron emission tomography (PET) Centiloid (CL) for Alzheimer's disease (AD) staging and screening. METHODS: Quantification of plasma pTau217R and Aß42/Aß40 employed immunoprecipitation-mass spectrometry. CL prediction models were developed on a cohort of 904 cognitively unimpaired, preclinical and early AD subjects and validated on two independent cohorts. RESULTS: Models integrating pTau217R outperformed Aß42/Aß40 alone, predicting amyloid levels up to 89.1 CL. High area under the receiver operating characteristic curve (AUROC) values (89.3% to 94.7%) were observed across a broad CL range (15 to 90). Utilizing pTau217R-based models for low amyloid levels reduced PET scans by 70.5% to 78.6%. DISCUSSION: pTau217R effectively predicts brain amyloid levels, surpassing cerebrospinal fluid Aß42/Aß40's range. Combining it with plasma Aß42/Aß40 enhances sensitivity for low amyloid detection, reducing unnecessary PET scans and expanding clinical utility. HIGHLIGHTS: Phosphorylated plasma Tau217 ratio (pTau217R) effectively predicts amyloid-PET Centiloid (CL) across a broad spectrum. Integrating pTau217R with Aß42/Aß40 extends the CL prediction upper limit to 89.1 CL. Combined model predicts amyloid status with high accuracy, especially in cognitively unimpaired individuals. This model identifies subjects above or below various CL thresholds with high accuracy. pTau217R-based models significantly reduce PET scans by up to 78.6% for screening out individuals with no/low amyloid.

Acute Cognitive Effects of the Dual Orexin Receptor Antagonist Lemborexant Compared With Suvorexant and Zolpidem in Recreational Sedative Users.

PURPOSE/BACKGROUND: As part of a human abuse potential (HAP) study of lemborexant (LEM), the effects of therapeutic (LEM 10 mg), and supratherapeutic doses of LEM 20 mg and LEM 30 mg on cognition and psychomotor performance were compared with placebo (PBO) and supratherapeutic doses of zolpidem (ZOL) 30 mg and suvorexant (SUV) 40 mg. Subjects (n = 32) were healthy, nondependent, recreational sedative users able to discriminate the effects of both SUV and ZOL from PBO on subjective drug measures. METHODS/PROCEDURES: The human abuse potential study was a single-dose, randomized, double-blind, PBO-controlled, 6-way crossover study. Eligible subjects admitted to the treatment phase completed the choice reaction test (CRT) and divided attention test. The CRT included measurements of recognition reaction time (RRT) and motor reaction time. FINDINGS/RESULTS: Recognition reaction time and mean maximum change from baseline (CFB max ) scores were significantly increased (slower performance) versus PBO for all LEM doses (all P < 0.001), ZOL ( P < 0.001), and SUV ( P = 0.004), and LEM (all doses) was not statistically different from ZOL or SUV. Motor reaction time and mean CFB max versus PBO were significantly increased for all LEM doses (all P < 0.001), and ZOL ( P < 0.001) and SUV ( P < 0.001). All LEM doses showed significantly decreased (better performance) mean CFB max versus ZOL (all P < 0.001), but not SUV. Notably, all cognitive effects in the CRT and divided attention test were limited to the main treatment phase (up to 8 hours postdose). IMPLICATIONS/CONCLUSIONS: All active doses of LEM, ZOL, and SUV generally increased reaction time and reduced divided attention capabilities versus PBO. However, at therapeutic/supratherapeutic doses, LEM led to significantly less cognitive impairment than supratherapeutic doses of ZOL in some measures.

Abuse Potential of Lemborexant, a Dual Orexin Receptor Antagonist, Compared With Zolpidem and Suvorexant in Recreational Sedative Users.

BACKGROUND: Lemborexant (LEM) is a dual orexin receptor antagonist approved for the treatment of insomnia in adults in multiple countries including the the United States, Japan, Canada, Australia and several Asian countries. PROCEDURES: This was a randomized, single-dose, single-center, double-blind, active-control, 6-way crossover study to evaluate LEM abuse potential. The study assessed oral doses of LEM 10 mg (LEM10), 20 mg (LEM20), and 30 mg (LEM30) compared with placebo (PBO), zolpidem (ZOL) immediate release 30 mg, and suvorexant (SUV) 40 mg. Subjects were healthy, nondependent, recreational sedative users able to discriminate/like the effects of both SUV and ZOL from PBO during a qualification phase. RESULTS: Abuse potential endpoints were analyzed in qualified subjects who received and completed all treatments (n = 32). On the "at this moment" drug-liking visual analog scale (VAS), mean maximum (peak) effect (primary endpoint) values were 78.4, 80.5, and 83.6 for LEM10, LEM20, and LEM30, respectively, which were all significantly greater than PBO (57.8; all P > 0.05) but not different from SUV (76.1) or ZOL (78.3). Similarly, for secondary endpoints overall drug-liking VAS and take-drug-again VAS, mean maximum (peak) effect values for all LEM doses were significantly greater than PBO ( P > 0.05) but not different compared with ZOL or SUV. CONCLUSIONS: For all doses, LEM demonstrated abuse potential versus PBO and appeared to have a similar abuse potential profile to ZOL and SUV in this study population. Lemborexant was well tolerated. Lemborexant has been placed in Schedule IV, the same drug schedule as ZOL and SUV.

E2027 Cardiac Safety Evaluation With Concentration-Response Modeling of ECG Data to Inform Dose Selection in Studies in Patients With Dementia With Lewy Bodies.

BACKGROUND: E2027 is a novel, highly selective and potent inhibitor of phosphodiesterase 9 in development for dementia with Lewy bodies. Cardiac safety assessments for emerging agents are essential to avoid drug-induced QT interval prolongation, which may predispose individuals to potentially fatal ventricular arrhythmias. To evaluate the cardiac safety of E2027 and to inform dose selection for the phase 2 study of E2027 in dementia with Lewy bodies, we evaluated concentration-response modeling of pooled electrocardiogram data. PATIENTS AND METHODS: A post hoc concentration-QTc analysis evaluated potential QT effects using data from 2 randomized, double-blind studies in healthy subjects: a single ascending dose (SAD) study and a multiple ascending dose (MAD) study. Daily E2027 doses ranged from 5 to 1200 mg. RESULTS: A linear mixed-effects model was used to establish the relationship between plasma concentrations of E2027 and change from the baseline of QTcF (ΔQTcF). A significant but shallow relationship was observed in the estimated slope of the concentration-ΔQTcF: 0.002 ms/ng/mL (90% confidence interval: 0.0007-0.0031) with a small, nonsignificant treatment effect-specific intercept of -0.6 ms. Based on this pooled concentration-QTc analysis, an effect on the QTcF interval >10 ms can be excluded up to E2027 plasma concentrations of ∼3579 ng/mL, corresponding to a dose at least 4-fold larger than the 50 mg phase 2 dose. CONCLUSION: This pooled post hoc analysis evaluating cardiac safety of E2027 demonstrated that clinically concerning QTcF prolongation and related cardiac complications are highly unlikely with proposed E2027 doses planned for phase 2.

Phase 1 Single Ascending and Multiple Ascending Dose Studies of Phosphodiesterase-9 Inhibitor E2027: Confirmation of Target Engagement and Selection of Phase 2 Dose in Dementia With Lewy Bodies Trial.

BACKGROUND: E2027 is a novel, highly selective and potent inhibitor of phosphodiesterase9 (PDE9) being evaluated as a treatment for dementia with Lewy bodies. METHODS: Phase 1, randomized, double-blind, single ascending dose (SAD, n=96) and multiple ascending dose (MAD, n=68) studies evaluated E2027 doses (5 to 1200 mg) in healthy subjects. The impact of age, race (Japanese/non-Japanese), and food on pharmacokinetics (PK)/pharmacodynamics were evaluated. Serial cerebrospinal fluid (CSF) samples were collected to assess the target engagement. RESULTS: E2027 PK profiles were biphasic (elimination half-life: ~30 hours. Approximately 3-fold accumulation was observed following multiple once-daily dosing. E2027 single doses of 50 to 400 mg resulted in mean maximum increases in CSF cyclic guanosine monophosphate ranging from 293% to 461% within 5.37 to 12.9 hours after dose administration to assess target engagement. Dose-response modelling of steady-state predose CSF cyclic guanosine monophosphate concentrations showed ≥200% increase from baseline is maintained with doses of ≥50 mg QD. The most common adverse events with E2027 were post-LP syndrome and back pain. PK profiles were similar between Japanese and non-Japanese. Higher exposure observed in fed versus fasted state was not considered clinically significant. PK exposure was higher in elderly subjects. CONCLUSIONS: S.E2027 was well-tolerated following single and multiple administration. E2027 achieved maximal and sustained target engagement at 50 mg QD, the dose selected for the phase 2 clinical trial.

Use of extended-release and immediate-release anti-seizure medications with a long half-life to improve adherence in epilepsy: A guide for clinicians.

Poor adherence to anti-seizure medications (ASMs) is associated with breakthrough seizures and potentially increased toxicity in patients with epilepsy. Extended-release (ER) drugs and immediate-release (IR) drugs with a long half-life (t1/2) that permit once-daily dosing (such as, perampanel, zonisamide, lamotrigine [IR, ER] and topiramate [ER]) have a number of advantages over short t1/2 ASMs that require multiple daily dosing. These advantages include simplification of dosing regimens, reduction in pill burden, and a decrease in the peak-to-trough fluctuations in serum drug concentration that may be associated with a decreased risk of adverse effects and seizures. Such properties have wider implications in improving patient adherence to treatment. This article is intended as a practical guide for clinicians that provides an overview of the features of ER ASMs and long t1/2 IR ASMs that are advantageous in the context of patient adherence and pharmacokinetic "forgiveness" (after missing a dose). In addition, we note that efforts to improve adherence should not depend solely on drug dosing regimens and drug pharmacokinetics, but should be part of a wider strategy that includes therapeutic drug monitoring, improved healthcare provider-patient dialogue, patient education, and the use of "reminder" technology.

Bioequivalence of perampanel fine granules and tablets in healthy Japanese subjects.

OBJECTIVE: Perampanel is an approved anti-seizure drug. A new formulation of perampanel fine granules (FG; 1% perampanel) has been developed for patients who are unable to take tablets. Bioequivalence between the 4-mg FG and tablet perampanel formulations, as well as their safety and tolerability, were assessed. MATERIALS AND METHODS: In this phase I, single-center, open-label, 2-period, 2-sequence, crossover, bioequivalence study (NCT03399734), healthy Japanese subjects were randomized to receive single doses of the 4-mg FG perampanel and 4-mg perampanel tablet (separated by a ≥ 6-week washout period). Plasma samples for perampanel concentration analysis were collected pre-dose and at intervals up to 168 hours post-dose. The maximum observed concentration (Cmax) and area under the concentration-time curve from time zero to 168 hours (AUC(0-168h)) were used to assess the bioequivalence of the two formulations. RESULTS: The 90% confidence intervals (CIs) for the geometric mean ratio of test/reference for Cmax and AUC(0-168h) were within the bioequivalence criteria of 80 - 125% (Cmax 90% CI 90.8%, 110%; AUC(0-168h) 90% CI 98.2%, 112%; N = 21). 10/24 (41.7%) subjects with FG experienced ≥ 1 treatment-emergent adverse event (TEAE). The events were mild in severity and resolved within 4 hours of onset. There were no deaths, severe TEAEs, serious AEs, or TEAEs leading to study-drug withdrawal. CONCLUSION: Bioequivalence of 4-mg FG and 4-mg tablet of perampanel was demonstrated. Both perampanel formulations were generally safe and well tolerated. These data suggest that perampanel FG may be a suitable alternative formulation for patients with epilepsy who have difficulties taking perampanel tablets.

A phase 1b/2, open-label, dose-escalation, and dose-confirmation study of eribulin mesilate in combination with capecitabine.

BACKGROUND: Capecitabine and eribulin are widely used as single agents in metastatic breast cancer (MBC) and have nonoverlapping toxicities. METHODS: In phase 1b (dose escalation), patients with advanced, treatment-refractory, solid tumours received eribulin mesilate intravenously in 21-day cycles according to schedule 1 (day 1) or schedule 2 (days 1, 8) with twice-daily oral capecitabine (1000 mg/m2 days 1-14). In phase 2 (dose confirmation), women with advanced/MBC and ≤3 prior chemotherapies received eribulin mesilate at the maximum tolerated dose (MTD) per the preferred schedule plus capecitabine. Primary objectives were MTD and dose-limiting toxicities (DLTs; phase 1b) and objective response rate (ORR; phase 2). Secondary objectives included progression-free survival (PFS), safety, and pharmacokinetics. RESULTS: DLTs occurred in 4/19 patients (schedule 1) and 2/15 patients (schedule 2). Eribulin pharmacokinetics were dose proportional, irrespective of schedule or capecitabine coadministration. The MTD of eribulin was 1.6 mg/m2 day 1 for schedule 1 and 1.4 mg/m2 days 1 and 8 for schedule 2. ORR in phase 2 (eribulin 1.4 mg/m2 days 1, 8 plus capecitabine) was 43% and median PFS 7.2 months. The most common treatment-related adverse events were neutropenia, leukopenia, alopecia, nausea, and lethargy. CONCLUSIONS: The combination of capecitabine and eribulin showed promising efficacy with manageable tolerability in patients with MBC.

Phase 1 dose-finding and pharmacokinetic study of eribulin-liposomal formulation in patients with solid tumours.

BACKGROUND: This phase 1 study examined the safety, tolerability, pharmacokinetics and preliminary efficacy of eribulin-liposomal formulation (eribulin-LF) in patients with advanced solid tumours. METHODS: Eligible patients with ECOG PS 0-1 were treated with eribulin-LF either on day 1 every 21 days (Schedule 1), or on days 1 and 15 every 28 days (Schedule 2). Doses ranged from 1.0 to 3.5 mg/m2, with dose escalation in a 3 + 3 design. The dose-expansion phase evaluated eribulin-LF in select tumour types. PRIMARY OBJECTIVES: maximum tolerated dose (MTD) and the recommended dose/schedule of eribulin-LF. RESULTS: Totally, 58 patients were enroled (median age = 62 years). The MTD was 1.4 mg/m2 (Schedule 1) or 1.5 mg/m2 (Schedule 2), the latter dose selected for the dose-expansion phase. Dose-limiting toxicity (DLTs) in Schedule 1: hypophosphatemia and increased transaminase levels. DLTs in Schedule 2: stomatitis, increased alanine aminotransferase, neutropenia and febrile neutropenia. The pharmacokinetic profile of eribulin-LF showed a similar half-life to that of eribulin (~30 h), but with a 5-fold greater maximum serum concentration and a 40-fold greater area-under-the-curve. Eribulin-LF demonstrated clinical activity with approximately 10% of patients in both schedules achieving partial responses. CONCLUSIONS: Eribulin-LF was well tolerated with a favourable pharmacokinetic profile. Preliminary evidence of clinical activity in solid tumours was observed.

Safety, pharmacokinetics, and preliminary efficacy of E6201 in patients with advanced solid tumours, including melanoma: results of a phase 1 study.

BACKGROUND: This phase 1 first-in-human study aimed to determine the maximum-tolerated dose (MTD), dose-limiting toxicities, and safety of E6201, and to establish recommended dosing in patients with advanced solid tumours, expanded to advanced melanoma. METHODS: Part A (dose escalation): sequential cohorts received E6201 intravenously (IV) over 30 min (once-weekly [qw; days (D)1 + 8 + 15 of a 28-day cycle]), starting at 20 mg/m2, increasing to 720 mg/m2 or the MTD. Part B (expansion): patients with BRAF-mutated or wild-type (WT) melanoma received E6201 320 mg/m2 IV over 60 minutes qw (D1 + 8 + 15 of a 28-day cycle) or 160 mg/m2 IV twice-weekly (D1 + 4 + 8 + 11 + 15 + 18 of a 28-day cycle; BRAF-mutated only). RESULTS: MTD in Part A (n = 25) was 320 mg/m2 qw, confirmed in Part B (n = 30). Adverse events included QT prolongation (n = 4) and eye disorders (n = 3). E6201 exposure was dose-related, with PK characterised by extensive distribution and fast elimination. One patient achieved PR during Part A (BRAF-mutated papillary thyroid cancer; 480 mg/m2 qw) and three during Part B (2 BRAF-mutated melanoma; 1 BRAF-WT melanoma; all receiving 320 mg/m2 qw). CONCLUSIONS: An intermittent regimen of E6201 320 mg/m2 IV qw for the first 3 weeks of a 28-day cycle was feasible and reasonably well-tolerated in patients with advanced solid tumours, including melanoma with brain metastases, with evidence of clinical efficacy.

A phase 1 study of eribulin mesylate (E7389), a novel microtubule-targeting chemotherapeutic agent, in children with refractory or recurrent solid tumors: A Children's Oncology Group Phase 1 Consortium study (ADVL1314).

BACKGROUND: Eribulin mesylate is a novel anticancer agent that inhibits microtubule growth, without effects on shortening, and promotes nonproductive tubulin aggregate formation. We performed a phase 1 trial to determine the dose-limiting toxicities (DLTs), maximum tolerated or recommended phase 2 dose (MTD/RP2D), and pharmacokinetics (PK) of eribulin in children with refractory or recurrent solid (excluding central nervous system) tumors. METHODS: Eribulin was administered intravenously on days 1 and 8 in 21-day cycles. Three dose levels (1.1, 1.4, and 1.8 mg/m2 /dose) were evaluated using the rolling six design with additional patients enrolled into a PK expansion cohort at the MTD. PK samples were obtained following the day 1, cycle 1 dose. RESULTS: Twenty-three patients, ages 3-17 (median 14) years were enrolled; 20 were evaluable for toxicity. DLTs occurred in 0/6 and 1/6 subjects at the 1.1 and 1.4 mg/m2 /dose, respectively. One subject at the 1.4 mg/m2 /dose had grade 4 neutropenia and grade 3 fatigue. At the 1.8 mg/m2 /dose, 2/5 subjects experienced dose-limiting (grade 4) neutropenia. Grade 3/4 non-DLTs included lymphopenia and hypokalemia, while low-grade toxicities included anorexia and nausea. No episodes of grade > 2 corrected QT interval prolongation or peripheral neuropathy were reported. Eribulin pharmacokinetic parameters were highly variable; the median elimination half-life was 39.6 (range 24.2-96.4) hr. A partial response was observed in one patient (Ewing sarcoma). CONCLUSIONS: Eribulin was well tolerated in children with refractory or recurrent solid tumors with neutropenia identified as the primary DLT. The RP2D of eribulin is 1.4 mg/m2 /dose on days 1 and 8 of a 21-day cycle.

A phase I, open-label, single-arm study for QT assessment of eribulin mesylate in patients with advanced solid tumors.

BACKGROUND: Several cancer therapies can prolong cardiac repolarization. This study assessed the potential of eribulin to affect cardiac repolarization in patients with advanced solid tumors. METHODS: In this Phase I, open-label, single-arm study, patients received eribulin mesylate (1.4 mg/m(2); Days 1 and 8 of a 21-day cycle). The primary objective was to assess the effect of eribulin on the QTcF pre- and post-infusion; QTcF and QTcNi were compared for ability to remove heart-rate dependence of the QT interval. Relationship between concentration of eribulin and ΔQTc was explored using linear mixed-effects analysis. Secondary objectives explored pharmacokinetics, safety, and tolerability. RESULTS: Twenty-six patients were enrolled. QTcNi was more effective than QTcF in correcting for heart-rate dependency of the QT interval. On Day 1, mean ΔQTcNi were ~0 at all timepoints. An apparent time-dependent increase in ΔQTc was observed: on Day 8, changes from baseline were larger and more variable, without clear relation to plasma levels of eribulin. Day 8 predose ΔQTcNi was 5 ms, post-infusion mean values ranged from 2 to 9 ms (largest mean ΔQTcNi at 6 h). No new or unexpected toxicities were reported. CONCLUSION: Eribulin demonstrated an acceptable safety profile and a minor prolongation of QTc not expected to be of clinical concern in oncology patients.

Pharmacokinetics of eribulin mesylate in patients with solid tumours receiving repeated oral rifampicin.

AIM: Eribulin mesylate is a non-taxane microtubule dynamics inhibitor that was recently approved for treatment of metastatic breast cancer. The aim of this study was to determine the effect of rifampicin, a CYP3A4 inducer, on the plasma pharmacokinetics of eribulin in patients with solid tumours. METHODS: An open-label, non-randomized phase I study was carried out. Patients received intravenous 1.4 mg m(-2) eribulin mesylate on days 1 and 15 and oral rifampicin 600 mg on days 9 to 20 of a 28 day cycle. Pharmacokinetic sampling for determination of eribulin plasma concentrations was performed up to 144 h following administration. AUC(0,∞) and C(max) for eribulin exposure without or with co-administration of rifampicin were subjected to an analysis of variance (anova) and corresponding 90% confidence intervals (CI) were calculated. Subsequently, patients were allowed to continue eribulin mesylate treatment with 1.4 mg m(-2) eribulin mesylate on days 1 and 8 of a 21 day cycle. Also the adverse event profile and anti-tumour activity were assessed. RESULTS: Fourteen patients were included and 11 patients were evaluable for pharmacokinetic analysis. Co-administration of rifampicin had no effect on single dose exposure to eribulin (geometric least square means ratio: AUC(0,∞) = 1.10, 90% CI 0.91, 1.34 and C(max) = 0.97, 90% 0.81, 1.17). The most common treatment-related grade ≥3 adverse events were grade 3 neutropenia (4/14, 29%), leucopenia and fatigue (both 3/14, 21%). CONCLUSIONS: These results indicate that eribulin mesylate may be safely co-administered with compounds that are CYP3A4 inducers.

Exposure-Response Analyses of Polysomnography and Subjective Sleep Efficacy End Points From the Phase 3 Trials of Lemborexant, a Dual Orexin Receptor Antagonist for the Treatment of Insomnia.

This report describes polysomnography and sleep diary exposure-response analyses from Study E2006-G000-304 (Study 304), a 1-month trial of 5- or 10-mg lemborexant, zolpidem, or placebo; and Study E2006-G000-303 (Study 303), a 6-month trial of 5- or 10-mg lemborexant or placebo. Studies 304 and 303 included 1006 (86%) and 956 (68%) (female) participants, respectively; >40% were ≥65 years, with individual lemborexant exposures derived from a previously described pharmacokinetic model. Linear mixed-effects analyses of polysomnography: latency to persistent sleep (LPS), sleep efficiency (SE), and wake after sleep onset (WASO) quantified the change from baseline given lemborexant exposure, time, and covariates, guided by consensus recommendations regarding clinical significance. A small impact of sex, body weight, and race was predicted for LPS and SE, irrespective of treatment. Effect of age on LPS was small; baseline SE was estimated to be 8% higher for a 50-year-old versus an 80-year-old, decreasing to 6% by 1 month. Baseline WASO was 13 minutes longer for Black versus White subjects, corresponding to a 5-minute lower change from baseline at the end of the study. For subjective end points, the statistically significant covariate effects for age, sex, and race were not deemed therapeutically relevant, likely reflecting physiologic sleep pattern changes across age and study subgroups. Both polysomnography and subjective analyses indicated clinically meaningful differences from baseline for both lemborexant treatments, with effects being greater for 10-mg versus 5-mg lemborexant, while indicating that covariate-specific lemborexant dose adjustments are not warranted.

ARIA in patients treated with lecanemab (BAN2401) in a phase 2 study in early Alzheimer's disease.

INTRODUCTION: Lecanemab is a humanized immunoglobulin G1 (IgG1) monoclonal antibody that preferentially targets soluble aggregated Aß species (protofibrils) with activity at amyloid plaques. Amyloid-related imaging abnormalities (ARIA) profiles appear to differ for various anti-amyloid antibodies. Here, we present ARIA data from a large phase 2 lecanemab trial (Study 201) in early Alzheimer's disease. METHODS: Study 201 trial was double-blind, placebo-controlled (core) with an open-label extension (OLE). Observed ARIA events were summarized and modeled via Kaplan-Meier graphs. An exposure response model was developed. RESULTS: In the phase 2 core and OLE, there was a low incidence of ARIA-E (<10%), with <3% symptomatic cases. ARIA-E was generally asymptomatic, mild-to-moderate in severity, and occurred early (<3 months). ARIA-E was correlated with maximum lecanemab serum concentration and incidence was higher in apolipoprotein E4 (ApoE4) homozygous carriers. ARIA-H and ARIA-E occurred with similar frequency in core and OLE. DISCUSSION: Lecanemab can be administered without titration with modest incidence of ARIA.

A combined physiologically-based pharmacokinetic and quantitative systems pharmacology model for modeling amyloid aggregation in Alzheimer's disease.

Antibody-mediated removal of aggregated ß-amyloid (Aß) is the current, most clinically advanced potential disease-modifying treatment approach for Alzheimer's disease. We describe a quantitative systems pharmacology (QSP) approach of the dynamics of Aß monomers, oligomers, protofibrils, and plaque using a detailed microscopic model of Aß40 and Aß42 aggregation and clearance of aggregated Aß by activated microglia cells, which is enhanced by the interaction of antibody-bound Aß. The model allows for the prediction of Aß positron emission tomography (PET) imaging load as measured by a standardized uptake value ratio. A physiology-based pharmacokinetic model is seamlessly integrated to describe target exposure of monoclonal antibodies and simulate dynamics of cerebrospinal fluid (CSF) and plasma biomarkers, including CSF Aß42 and plasma Aß42 /Aß40 ratio biomarkers. Apolipoprotein E genotype is implemented as a difference in microglia clearance. By incorporating antibody-bound, plaque-mediated macrophage activation in the perivascular compartment, the model also predicts the incidence of amyloid-related imaging abnormalities with edema (ARIA-E). The QSP platform is calibrated with pharmacological and clinical information on aducanumab, bapineuzumab, crenezumab, gantenerumab, lecanemab, and solanezumab, predicting adequately the change in PET imaging measured amyloid load and the changes in the plasma Aß42 /Aß40 ratio while slightly overestimating the change in CSF Aß42 . ARIA-E is well predicted for all antibodies except bapineuzumab. This QSP model could support the clinical trial design of different amyloid-modulating interventions, define optimal titration and maintenance schedules, and provide a first step to understand the variability of biomarker response in clinical practice.

Mass balance study of [¹4C]eribulin in patients with advanced solid tumors.

This mass balance study investigated the metabolism and excretion of eribulin, a nontaxane microtubule dynamics inhibitor with a novel mechanism of action, in patients with advanced solid tumors. A single approximately 2 mg (approximately 80 µCi) dose of [¹4C]eribulin acetate was administered as a 2 to 5 min bolus injection to six patients on day 1. Blood, urine, and fecal samples were collected at specified time points on days 1 to 8 or until sample radioactivity was ≤1% of the administered dose. Mean plasma eribulin exposure (627 ng · h/ml) was comparable with that of total radioactivity (568 ng Eq · h/ml). Time-matched concentration ratios of eribulin to total radioactivity approached unity in blood and plasma, indicating that unchanged parent compound constituted almost all of the eribulin-derived radioactivity. Only minor metabolites were detected in plasma samples up to 60 min postdose, pooled across patients, each metabolite representing ≤0.6% of eribulin. Elimination half-lives for eribulin (45.6 h) and total radioactivity (42.3 h) were comparable. Eribulin-derived radioactivity excreted in feces was 81.5%, and that of unchanged eribulin was 61.9%. Renal clearance (0.301 l/h) was a minor component of total eribulin clearance (3.93 l/h). Eribulin-derived radioactivity excreted in urine (8.9%) was comparable with that of unchanged eribulin (8.1%), indicating minimal excretion of metabolite(s) in urine. Total recovery of the radioactive dose was 90.4% in urine and feces. Overall, no major metabolites of eribulin were detected in plasma. Eribulin is eliminated primarily unchanged in feces, whereas urine constitutes a minor route of elimination.

Pharmacodynamics and pharmacokinetics of the novel PAR-1 antagonist vorapaxar (formerly SCH 530348) in healthy subjects.

PURPOSE: The aim of our study was to evaluate the pharmacology of vorapaxar (SCH 530348), an oral PAR-1 antagonist, in healthy volunteers. METHODS AND RESULTS: In two randomized, placebo-controlled studies, subjects received either single ascending doses of vorapaxar (0.25, 1, 5, 10, 20, or 40 mg; n = 50), multiple ascending doses of vorapaxar (1, 3, or 5 mg/day for 28 days; n = 36), a loading dose (10 or 20 mg) followed by daily maintenance doses (1 mg) for 6 days (n = 12), or placebo. Single 20- and 40-mg doses of vorapaxar completely inhibited thrombin receptor activating peptide (TRAP)-induced platelet aggregation (>80% inhibition) at 1 h and sustained this level of inhibition for ≥72 h. Multiple doses yielded complete inhibition on Day 1 (5 mg/day) and Day 7 (1 and 3 mg/day). Adverse events were generally mild, transient, and unrelated to dose. CONCLUSION: Vorapaxar provided rapid and sustained dose-related inhibition of platelet aggregation without affecting bleeding or clotting times.