BACKGROUND: Alzheimer 's disease is a progressive, irreversible, and fatal disease for which accumulation of amyloid beta is thought to play a key role in pathogenesis. Aducanumab is a human monoclonal antibody directed against aggregated soluble and insoluble forms of amyloid beta. OBJECTIVES: We evaluated the efficacy and safety of aducanumab in early Alzheimer's disease. DESIGN: EMERGE and ENGAGE were two randomized, double-blind, placebo-controlled, global, phase 3 studies of aducanumab in patients with early Alzheimer's disease. SETTING: These studies involved 348 sites in 20 countries. PARTICIPANTS: Participants included 1638 (EMERGE) and 1647 (ENGAGE) patients (aged 50-85 years, confirmed amyloid pathology) who met clinical criteria for mild cognitive impairment due to Alzheimer's disease or mild Alzheimer's disease dementia, of which 1812 (55.2%) completed the study. INTERVENTION: Participants were randomly assigned 1:1:1 to receive aducanumab low dose (3 or 6 mg/kg target dose), high dose (10 mg/kg target dose), or placebo via IV infusion once every 4 weeks over 76 weeks. MEASUREMENTS: The primary outcome measure was change from baseline to week 78 on the Clinical Dementia Rating Sum of Boxes (CDR-SB), an integrated scale that assesses both function and cognition. Other measures included safety assessments; secondary and tertiary clinical outcomes that assessed cognition, function, and behavior; and biomarker endpoints. RESULTS: EMERGE and ENGAGE were halted based on futility analysis of data pooled from the first approximately 50% of enrolled patients; subsequent efficacy analyses included data from a larger data set collected up to futility declaration and followed prespecified statistical analyses. The primary endpoint was met in EMERGE (difference of −0.39 for highdose aducanumab vs placebo [95% CI, −0.69 to −0.09; P=.012; 22% decrease]) but not in ENGAGE (difference of 0.03, [95% CI, −0.26 to 0.33; P=.833; 2% increase]). Results of biomarker substudies confirmed target engagement and dose-dependent reduction in markers of Alzheimer's disease pathophysiology. The most common adverse event was amyloid-related imaging abnormalities-edema. CONCLUSIONS: Data from EMERGE demonstrated a statistically significant change across all four primary and secondary clinical endpoints. ENGAGE did not meet its primary or secondary endpoints. A dose-and time-dependent reduction in pathophysiological markers of Alzheimer 's disease was observed in both trials.

Summary Lung nociceptors initiate cough and bronchoconstriction. To elucidate if these fibers also contribute to allergic airway inflammation we stimulated lung nociceptors with capsaicin and observed increased neuropeptide release and immune cell infiltration. In contrast, ablating Nav1.8+ sensory neurons or silencing them with QX-314, a charged sodium channel inhibitor that enters via large pore ion channels to specifically block nociceptors, substantially reduced ovalbumin or house dust mite-induced airway inflammation and bronchial hyperresponsiveness. We also discovered that IL-5, a cytokine produced by activated immune cells, acts directly on nociceptors to induce release of vasoactive intestinal peptide (VIP). VIP then stimulates CD4+ and resident innate lymphoid type 2 cells, creating an inflammatory signaling loop that promotes allergic inflammation. Our results indicate that nociceptors amplify pathological adaptive immune responses and that silencing these neurons with QX-314 interrupts this neuro-immune interplay, revealing a potential new therapeutic strategy for asthma.

Background Aducanumab is a human monoclonal antibody that selectively targets aggregated forms of Aβ, including soluble oligomers and insoluble fibrils. EMERGE and ENGAGE are two 18‐month, randomized, double‐blind, placebo‐controlled, global Phase 3 studies with identical design that evaluated the efficacy and safety of aducanumab in patients aged 50–85 years with early Alzheimer’s disease (MCI due to AD or mild AD dementia). Method Key inclusion criteria included positive amyloid PET, MMSE score of 24–30, CDR Global score of 0.5, and an RBANS‐DMI score ≤85. During the 18‐month placebo‐controlled period, patients were randomized 1:1:1 to low‐dose aducanumab, high‐dose aducanumab, or placebo, administered via IV infusion every 4 weeks. The primary endpoint for EMERGE and ENGAGE was change from baseline at Week 78 on the CDR‐SB. Secondary endpoints included change from baseline on MMSE, ADAS‐Cog13, and ADCS‐ADL‐MCI. Result Following pre‐planned futility analysis, analysis of the data from the final database lock showed that EMERGE met its primary endpoint, based on the pre‐specified statistical analysis plan. Patients treated with high dose aducanumab showed a significant reduction of clinical decline from baseline in CDR‐SB scores at 78 weeks (22% versus placebo, P = 0.01). ENGAGE did not meet its primary endpoint. However, data from patients in ENGAGE who achieved sufficient exposure to high dose aducanumab supported the findings of EMERGE. Conclusion EMERGE met its primary endpoint, based on the pre‐specified statistical analysis plan. Data from a subset of patients in ENGAGE support the results of EMERGE. The safety and tolerability profile of aducanumab in EMERGE and ENGAGE was consistent with previous studies of aducanumab.

Epoxyeicosatrienoic acids (EETs) are cytochrome P450-epoxygenase-derived metabolites of arachidonic acid that act as endogenous signaling molecules in multiple biological systems. Here we have investigated the specific contribution of 5,6-EET to transient receptor potential (TRP) channel activation in nociceptor neurons and its consequence for nociceptive processing. We found that, during capsaicin-induced nociception, 5,6-EET levels increased in dorsal root ganglia (DRGs) and the dorsal spinal cord, and 5,6-EET is released from activated sensory neurons in vitro. 5,6-EET potently induced a calcium flux (100 nm) in cultured DRG neurons that was completely abolished when TRPA1 was deleted or inhibited. In spinal cord slices, 5,6-EET dose dependently enhanced the frequency, but not the amplitude, of spontaneous EPSCs (sEPSCs) in lamina II neurons that also responded to mustard oil (allyl isothiocyanate), indicating a presynaptic action. Furthermore, 5,6-EET-induced enhancement of sEPSC frequency was abolished in TRPA1-null mice, suggesting that 5,6-EET presynaptically facilitated spinal cord synaptic transmission by TRPA1. Finally, in vivo intrathecal injection of 5,6-EET caused mechanical allodynia in wild-type but not TRPA1-null mice. We conclude that 5,6-EET is synthesized on the acute activation of nociceptors and can produce mechanical hypersensitivity via TRPA1 at central afferent terminals in the spinal cord.

Objectives:To investigate the immune response to vaccinations in patients with relapsing forms of MS treated with delayed-release dimethyl fumarate (DMF) vs nonpegylated interferon (IFN).Methods:In this open-label, multicenter study, patients received 3 vaccinations: (1) tetanus-diphtheria toxoid (Td) to test T-cell–dependent recall response, (2) pneumococcal vaccine polyvalent to test T-cell–independent humoral response, and (3) meningococcal (groups A, C, W-135, and Y) oligosaccharide CRM197 conjugate to test T-cell–dependent neoantigen response. Eligible patients were aged 18–55 years, diagnosed with relapsing-remitting MS (RRMS), and either treated for ≥6 months with an approved dose of DMF or for ≥3 months with an approved dose of nonpegylated IFN. Primary end point was the proportion of patients with ≥2-fold rise in antitetanus serum IgG levels from prevaccination to 4 weeks after vaccination.Results:Seventy-one patients (DMF treated, 38; IFN treated, 33) were enrolled. The mean age was 45.3 years (range 27–55); 86% were women. Responder rates (≥2-fold rise) to Td vaccination were comparable between DMF- and IFN-treated groups (68% vs 73%). Responder rates (≥2-fold rise) were also similar between DMF- and IFN-treated groups for diphtheria antitoxoid (58% vs 61%), pneumococcal serotype 3 (66% vs 79%), pneumococcal serotype 8 (95% vs 88%), and meningococcal serogroup C (53% vs 53%), all p > 0.05. In a post hoc analysis, no meaningful differences were observed between groups in the proportion of responders when stratified by age category or lymphocyte count.Conclusions:DMF-treated patients mount an immune response to recall, neoantigens, and T-cell–independent antigens, which was comparable with that of IFN-treated patients and provided adequate seroprotection.ClinicalTrials.gov identifier:NCT02097849.Classification of evidence:This study provides Class II evidence that patients with RRMS treated with DMF respond to vaccinations comparably with IFN-treated patients.

BACKGROUND AND PURPOSESelective nociceptor fibre block is achieved by introducing the cell membrane impermeant sodium channel blocker lidocaine N-ethyl bromide (QX-314) through transient receptor potential V1 (TRPV1) channels into nociceptors. We screened local anaesthetics for their capacity to activate TRP channels, and characterized the nerve block obtained by combination with QX-314. EXPERIMENTAL APPROACHWe investigated TRP channel activation in dorsal root ganglion (DRG) neurons by calcium imaging and patch-clamp recordings, and cellular QX-314 uptake by MS. To characterize nerve block, compound action potential (CAP) recordings from isolated nerves and behavioural responses were analysed. KEY RESULTSOf the 12 compounds tested, bupivacaine was the most potent activator of ruthenium red-sensitive calcium entry in DRG neurons and activated heterologously expressed TRPA1 channels. QX-314 permeated through TRPA1 channels and accumulated intracellularly after activation of these channels. Upon sciatic injections, QX-314 markedly prolonged bupivacaine's nociceptive block and also extended (to a lesser degree) its motor block. Bupivacaine's blockade of C-, but not A-fibre, CAPs in sciatic nerves was extended by co-application of QX-314. Surprisingly, however, this action was the same in wild-type, TRPA1-knockout and TRPV1/TRPA1-double knockout mice, suggesting a TRP-channel independent entry pathway. Consistent with this, high doses of bupivacaine promoted a non-selective, cellular uptake of QX-314. CONCLUSIONS AND IMPLICATIONSBupivacaine, combined with QX-314, produced a long-lasting sensory nerve block. This did not require QX-314 permeation through TRPA1, although bupivacaine activated these channels. Regardless of entry pathway, the greatly extended duration of block produced by QX-314 and bupivacaine may be clinically useful.

Background: In phase 3 trials, delayed-release dimethyl fumarate (DMF; also known as gastroresistant DMF) demonstrated efficacy in relapsing-remitting multiple sclerosis (MS). Gastrointestinal (GI) events were associated with DMF treatment. The single-arm, open-label MANAGE study examined the incidence, severity, duration, and management of GI events in adults with relapsing MS initiating DMF treatment in clinical practice in the United States shortly after marketing approval. Patients and Methods: Patients (N = 233) took DMF for up to 12 weeks and recorded information regarding GI events using an eDiary and numerical rating scales. Results: Overall, 54.1% of patients used symptomatic therapy and had GI symptoms. The incidence of GI events was highest in the first month of treatment. The duration of GI events varied by event type, and severity was generally mild to moderate. Decreased severity was seen in patients treated with antacids, bismuth subsalicylate, acid-secretion blockers, antidiarrheals, and antiemetics. Less than 10% of patients were using symptomatic therapy for GI events by week 12 of DMF treatment. A modest reduction in severe GI events was observed in patients who regularly took DMF with food compared with patients who did not. The incidence of GI-related events was comparable in patients with or without a history of GI abnormalities and in patients who did or did not use alcohol or tobacco. Conclusions: Gastrointestinal events associated with DMF are generally transient, mild to moderate in severity, and manageable. Symptomatic therapy and dosing with food may mitigate these events.

Objective The radiologically isolated syndrome (RIS) represents the earliest detectable pre‐clinical phase of multiple sclerosis (MS). This study evaluated the impact of therapeutic intervention in preventing first symptom manifestation at this stage in the disease spectrum. Methods We conducted a multi‐center, randomized, double‐blinded, placebo‐controlled study involving people with RIS. Individuals without clinical symptoms typical of MS but with incidental brain MRI anomalies consistent with central nervous system (CNS) demyelination were included. Within 12 MS centers in the United States, participants were randomly assigned 1:1 to oral dimethyl fumarate (DMF) 240 mg twice daily or placebo. The primary endpoint was the time to onset of clinical symptoms attributable to a CNS demyelinating event within a follow‐up period of 96 weeks. An intention‐to‐treat analysis was applied to all participating individuals in the primary and safety investigations. The study is registered at http://clinicaltrials.gov, NCT02739542 (ARISE). Results Participants from 12 centers were recruited from March 9, 2016, to October 31, 2019, with 44 people randomized to dimethyl fumarate and 43 to placebo. Following DMF treatment, the risk of a first clinical demyelinating event during the 96‐week study period was highly reduced in the unadjusted Cox proportional‐hazards regression model (hazard ratio [HR] = 0.18, 95% confidence interval [CI] = 0.05–0.63, p = 0.007). More moderate adverse reactions were present in the DMF (34 [32%]) than placebo groups (19 [21%]) but severe events were similar (DMF, 3 [5%]; placebo, 4 [9%]). Interpretation This is the first randomized clinical trial demonstrating the benefit of a disease‐modifying therapy in preventing a first acute clinical event in people with RIS. ANN NEUROL 2023;93:604–614