Safety and Efficacy of Lemborexant in Patients With Irregular Sleep-Wake Rhythm Disorder and Alzheimer's Disease Dementia: Results From a Phase 2 Randomized Clinical Trial

BACKGROUND

Irregular sleep-wake rhythm disorder (ISWRD) is a common sleep disorder in individuals with Alzheimer's disease dementia (AD-D).

OBJECTIVES

This exploratory phase 2 proof-of-concept and dose-finding clinical trial evaluated the effects of lemborexant compared with placebo on circadian rhythm parameters, nighttime sleep, daytime wakefulness and other clinical measures of ISWRD in individuals with ISWRD and mild to moderate AD-D.

DESIGN

Multicenter, randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Sites in the United States, Japan and the United Kingdom.

PARTICIPANTS

Men and women 60 to 90 years of age with documentation of diagnosis with AD-D and Mini-Mental State Exam (MMSE) score 10 to 26.

INTERVENTION

Subjects were randomized to placebo or one of four lemborexant treatment arms (2.5 mg, 5 mg, 10 mg or 15 mg) once nightly at bedtime for 4 weeks.

MEASUREMENTS

An actigraph was used to collect subject rest-activity data, which were used to calculate sleep-related, wake-related and circadian rhythm-related parameters. These parameters included least active 5 hours (L5), relative amplitude of the rest-activity rhythm (RA) and mean duration of sleep bouts (MDSB) during the daytime. The MMSE and the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) were used to assess for changes in cognitive function.

RESULTS

Sixty-two subjects were randomized and provided data for circadian, daytime and nighttime parameters (placebo, n = 12; lemborexant 2.5 mg [LEM2.5], n = 12; lemborexant 5 mg [LEM5], n = 13, lemborexant 10 mg [LEM10], n = 13 and lemborexant 15 mg [LEM15], n = 12). Mean L5 showed a decrease from baseline to week 4 for LEM2.5, LEM5 and LEM15 that was significantly greater than with placebo (all p < 0.05), suggesting a reduction in restlessness. For RA, LS mean change from baseline to week 4 versus placebo indicated greater distinction between night and day with all dose levels of lemborexant, with significant improvements seen with LEM5 and LEM15 compared with placebo (both p < 0.05). The median percentage change from baseline to week 4 in MDSB during the daytime indicated a numerical decrease in duration for LEM5, LEM10 and LEM15, which was significantly different from placebo for LEM5 and LEM15 (p < 0.01 and p = 0.002, respectively). There were no serious treatment-emergent adverse events or worsening of cognitive function, as assessed by the MMSE and ADAS-Cog. Lemborexant was well tolerated. No subjects discontinued treatment.

CONCLUSIONS

This study provides preliminary evidence of the potential utility of lemborexant as a treatment to address both nighttime and daytime symptoms in patients with ISWRD and AD-D.

Baseline autoantibody profiles predict normalization of complement and anti-dsDNA autoantibody levels following rituximab treatment in systemic lupus erythematosus

B cells are thought to play a major role in the pathogenesis of systemic lupus erythematosus (SLE). Rituximab (RTX), a chimeric anti-CD20 mAb, effectively depletes CD20( +) peripheral B cells. Recent results from EXPLORER, a placebo-controlled trial of RTX in addition to aggressive prednisone and immunosuppressive therapy, showed similar levels of clinical benefit in patients with active extra-renal SLE despite effective B cell depletion. We performed further data analyses to determine whether significant changes in disease activity biomarkers occurred in the absence of clinical benefit. We found that RTX-treated patients with baseline autoantibodies (autoAbs) had decreased anti-dsDNA and anti-cardiolipin autoAbs and increased complement levels. Patients with anti-dsDNA autoAb who lacked baseline RNA binding protein (RBP) autoAbs showed increased complement and decreased anti-dsDNA autoAb in response to RTX. Other biomarkers, such as baseline BAFF levels or IFN signature status did not predict enhanced effects of RTX therapy on complement or anti-dsDNA autoAb levels. Finally, platelet levels normalized in RTX-treated patients who entered the study with low baseline counts. Together, these findings demonstrate clear biologic activity of RTX in subsets of SLE patients, despite an overall lack of incremental clinical benefit with RTX in the EXPLORER trial.

A phase I study of trastuzumab-MCC-DM1 (T-DM1), a first-in-class HER2 antibody-drug conjugate (ADC), in patients (pts) with HER2+ metastatic breast cancer (BC)

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Background: ADCs utilize tumor-specific and/or over-expressed surface antigens that undergo internalization to deliver highly potent anti-tumor agents via linkage to antigen-specific monoclonal antibodies (MoAbs). T-DM1 contains the humanized anti-HER2 MoAb trastuzumab (T) previously demonstrated to prolong survival in HER2+ BC to which a highly potent antimicrotubule drug (DM1) derived from maytansine has been chemically linked. Maytansine has been studied as a free drug with responses noted in breast and lung cancer pts; principal adverse events (AEs) were nausea, vomiting, diarrhea, and neuropathy. The MCC linker employed in T-DM1 provides a stable bond between T and DM1 that is designed to prolong exposure and reduce the toxicity of T-DM1 while maintaining activity; T-DM1 is the first ADC with an MCC linker in clinical trials. T-DM1 has activity in T-resistant HER2+ BC xenografts; its principal preclinical toxicities were reversible transaminase elevations, reversible decreases in platelets, and neuropathy. Methods: This ongoing first-in-human phase I study is evaluating the safety and pharmacokinetics (PK) of T-DM1 given IV q3 weeks to pts with HER2+ metastatic BC who have progressed on a T-containing regimen. Results: Seven pts (median age 58 (range 47–70); all PS 0–1; median number prior chemo regimens 6 (range 5–11)) have received 24 doses of T-DM1 at 5 dose levels (0.3–4.8 mg/kg). Related grade (gr) 1–2 AEs include elevations in hepatic transaminases (2 pts), fatigue (2 pts), anemia (1 pt), and thrombocytopenia (TCP, 1 pt). Related gr 3–4 AEs have been limited to rapidly reversible gr 4 TCP at 4.8 mg/kg (1 pt). There has been no cardiac toxicity. Consistent with preclinical modeling, dose dependent decrease in clearance was observed for T-DM1 across dose levels. One pt at 2.4 mg/kg has maintained an ongoing partial response for 6 cycles. Conclusions: At these initial doses, gr =2 AEs related to T-DM1 have been infrequent and manageable; gr 4 (dose-limiting) rapidly reversible TCP was seen at 4.8 mg/kg. T-DM1 PK is consistent with q3-week dosing. Objective tumor response has been observed. Enrollment is ongoing to determine the maximum tolerated dose of q3-week T-DM1.

No significant financial relationships to disclose.

Identification of predictive markers of clinical activity from a phase II trial of single agent pertuzumab (rhuMab 2C4), a HER dimerization inhibitor, in advanced ovarian cancer (OC)

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Background: Pertuzumab (P), a humanized HER2 antibody, represents a new class of targeted agents called HER dimerization inhibitors (HDIs). P inhibits dimerization of HER2 with EGFR, HER3 and HER4, and subsequently inhibits signaling through MAP and PI3 kinases. Interim data from a phase II trial suggested that P has activity in OC, especially in a subset of tumors with activated HER2 (Abstract #5051 ASCO 2005). Methods: 123 pts with relapsed OC were treated with P. Cohort 1 was treated with 840mg followed by 420mg and cohort 2 with 1050mg every 3 weeks. Fresh tissue biopsies were mandated from Cohort 1, and archival formalin fixed paraffin tissue (FFPET ) were obtained from both cohorts. Molecular expression studies from FFPET and fresh tissue were conducted. Results: From final data of 117 evaluable pts, 5 pts had objective partial responses (RR = 4.3%). Eight pts (6.8%) had SD for ≥ 6 months, and an additional 4 pts (3.4%) had SD with CA-125 reduction of ≥50%. Overall rate of activity = 14.5%. Of the 65 fresh tumor biopsies, 28 were evaluable and 8 (28.6%) were positive for phosphorylated HER2 (pHER2) by ELISA. Among pts who had pHER2 status determined, TTP was 20.9 weeks for pHER2+ pts (n=8), compared to 5.8 weeks for pHER2- (n = 20). Data from microarray expression profiling were analyzed with respect to pHER2 status from the same tumors. The expression levels of HER2, EGFR and HER3 in combination with the expression of certain HER ligands may be predictive of pHER2 status. We have extended these analyses to qRT-PCR from macrodissected FFPET of HER receptors and ligands. This was analyzed with respect to clinical outcome. Preliminary analyses of expression data suggest that HER receptors and ligands may be promising candidates for diagnostic markers. Updated data in 78 OC pts will be presented. Conclusions: Clinical activity was observed in 14.5% of pts with heavily pretreated OC (PRs, SD ≥ 6 months, and SD with CA-125 reductions of ≥50%). This study suggests that P may be active in OC, and that specific HER receptors and ligands may be promising diagnostics for identifying tumors responsive to P.

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A genetic screen for behavioral mutations that perturb dopaminergic homeostasis in mice

Disruption of dopaminergic (DA) systems is thought to play a central role in the addictive process and in the pathophysiology of schizophrenia. Although inheritance plays an important role in the predisposition to these disorders, the genetic basis of this is not well understood. To provide additional insight, we have performed a modifier screen in mice designed to identify mutations that perturb DA homeostasis. With a genetic background sensitized by a mutation in the dopamine transporter (DAT), we used random chemical mutagenesis and screened for mutant mice with locomotor abnormalities. Four mutant lines were identified with quantitatively elevated levels of locomotor activity. Mapping of mutations in these lines identified two loci that alter activity only when dopamine levels are elevated by a DAT mutation and thus would only have been uncovered by this type of approach. One of these quantitative trait loci behaves as an enhancer of DA neurotransmission, whereas the other may act as a suppressor. In addition, we also identified three loci which are not dependent on the sensitized background but which also contribute to the overall locomotor phenotype.

Power and sample size for ordered categorical data

We propose a new method for computing power and sample size for linear rank tests of differences between two ordered multinomial populations. The method is flexible in that it is applicable to any general alternative hypothesis and for any choice of rank scores. We show that the method, though asymptotic, closely approximates existing exact methods. At the same time it overcomes the computational limitations of the exact methods. This advantage makes our asymptotic approach more practical for sample size computations at the planning stages of a large study. We illustrate the method with data arising from both proportional and non-proportional odds models in the two ordered multinomial setting.