Implications of therapy interruption on monthly migraine days and modified migraine disability assessment in patients treated with erenumab for chronic and episodic migraine: SQUARE study interim results.

BACKGROUND: There are limited real-world data in Switzerland examining the impact of erenumab, a fully human IgG2 monoclonal antibody targeting the calcitonin gene-related peptide (CGRP) receptor, on migraine-related quality of life. OBJECTIVE: This 18-month interim analysis of 172 patients with episodic or chronic migraine from the SQUARE study provides first prospective insights on the impact of mandatory erenumab treatment interruption, following Swiss-reimbursement requirements, in a real-world clinical setting in Switzerland. FINDINGS: Recruited patients receiving 70 or 140 mg erenumab underwent treatment interruption on average 11.2 months after therapy onset with a mean duration of 4 months. There were sustained improvements in mean monthly migraine days (MMD) and migraine disability (mMIDAS) during initial treatment with erenumab. Treatment interruption was associated with a temporary worsening of condition. Symptoms ameliorated upon therapy reuptake reaching improvements similar to pre-break within 3 months. CONCLUSIONS: Treatment interruption was associated with a temporary worsening of condition, which improved again after therapy restart.

Prevalence and Burden of Migraine in Switzerland: Cross-Sectional Study in ten Specialised Headache Centres from the BECOME Study.

INTRODUCTION: There is limited real-world evidence on the burden of migraine among patients with prior preventive treatment failure (PPTF). In the BECOME Swiss subanalysis, we aimed to assess current prevalence of PPTF in patients with migraine seen at specialised headache centres in Switzerland and burden of migraine in these patients. Furthermore, we assessed this burden in subgroups stratified by monthly migraine days (MMDs) and number of PPTFs. METHODS: BECOME was a prospective, multicentre, non-interventional two-part study conducted in 17 countries across Europe and Israel. This subanalysis includes patients visiting ten headache specialist centres in Switzerland. In part 1, patients visiting the centres over 3 months were screened by physicians for frequency of PPTF, MMD and other migraine characteristics. Patients with ≥ 1 PPTF and ≥ 4 MMDs were invited to take part in part 2. The primary endpoint was the proportion of patients with ≥ 1 PPTF (part 1). Other endpoints included proportion of patients specified by number of PPTF and MMD (part 1, part 2), and impact of migraine on patient-reported outcomes (PROs; part 2). RESULTS: Patients (1677) from ten Swiss centres were included in part 1, of which 855 (51.0%) reported ≥ 1 PPTF. One hundred fifty-five patients were included in part 2: 6.5% reported ≥ 4 PPTFs and 43.2% reported ≥ 15 MMDs. Mean EuroQoL 5 and EuroQoL visual analogue scale (EQ-VAS) were 0.8 ± 0.2 and 69.6 ± 20.2, respectively, suggesting a mild level of impairment in the daily functioning and self-reported health of the patients. Mean six-item Headache Impact Test (HIT-6) and modified Migraine Disability Assessment (mMIDAS) scores were 63.3 ± 6.5 and 22.7 ± 21.8, respectively, corresponding to severe migraine burden. Patients also reported impairment in work-related productivity and general activities (48.6 ± 22.8) but no associations of anxiety (7.2 ± 4.4) or depression (6.0 ± 4.4) with migraine were noted. Burden of migraine increased with increasing frequency of PPTF and MMD. CONCLUSIONS: Migraine-related quality of life, as well as work productivity are significantly affected in Swiss patients with migraine. Increasing migraine burden is associated with increasing migraine frequency and prior treatment failures.

Swiss QUality of life and healthcare impact Assessment in a Real-world Erenumab treated migraine population (SQUARE study): interim results.

BACKGROUND: The fully human monoclonal antibody erenumab, which targets the calcitonin gene-related peptide (CGRP) receptor, was licensed in Switzerland in July 2018 for the prophylactic treatment of migraine. To complement findings from the pivotal program, this observational study was designed to collect and evaluate clinical data on the impact of erenumab on several endpoints, such as quality of life, migraine-related impairment and treatment satisfaction in a real-world setting. METHODS: An interim analysis was conducted after all patients completed 6 months of erenumab treatment. Patients kept a headache diary and completed questionnaires at follow up visits. The overall study duration comprises 24 months. RESULTS: In total, 172 adults with chronic or episodic migraine from 19 different sites across Switzerland were enrolled to receive erenumab every 4 weeks. At baseline, patients had 16.6 ± 7.2 monthly migraine days (MMD) and 11.6 ± 7.0 acute migraine-specific medication days per month. After 6 months, erenumab treatment reduced Headache Impact Test (HIT-6™) scores by 7.7 ± 8.4 (p < 0.001), the modified Migraine Disability Assessment (mMIDAS) by 14.1 ± 17.8 (p < 0.001), MMD by 7.6 ± 7.0 (p < 0.001) and acute migraine-specific medication days per month by 6.6 ± 5.4 (p < 0.001). Erenumab also reduced the impact of migraine on social and family life, as evidenced by a reduction of Impact of Migraine on Partners and Adolescent Children (IMPAC) scores by 6.1 ± 6.7 (p < 0.001). Patients reported a mean effectiveness of 67.1, convenience of 82.4 and global satisfaction of 72.4 in the Treatment Satisfaction Questionnaire for Medication (TSQM-9). In total, 99 adverse events (AE) and 12 serious adverse events (SAE) were observed in 62 and 11 patients, respectively. All SAE were regarded as not related to the study medication. CONCLUSIONS: Overall quality of life improved and treatment satisfaction was rated high with erenumab treatment in real-world clinical practice. In addition, the reported impact of migraine on spouses and children of patients was reduced. TRIAL REGISTRATION: BASEC ID 2018-02,375 in the Register of All Projects in Switzerland (RAPS).

The Neurite Outgrowth Inhibitory Nogo-A-Δ20 Region Is an Intrinsically Disordered Segment Harbouring Three Stretches with Helical Propensity.

Functional recovery from central neurotrauma, such as spinal cord injury, is limited by myelin-associated inhibitory proteins. The most prominent example, Nogo-A, imposes an inhibitory cue for nerve fibre growth via two independent domains: Nogo-A-Δ20 (residues 544-725 of the rat Nogo-A sequence) and Nogo-66 (residues 1026-1091). Inhibitory signalling from these domains causes a collapse of the neuronal growth cone via individual receptor complexes, centred around sphingosine 1-phosphate receptor 2 (S1PR2) for Nogo-A-Δ20 and Nogo receptor 1 (NgR1) for Nogo-66. Whereas the helical conformation of Nogo-66 has been studied extensively, only little structural information is available for the Nogo-A-Δ20 region. We used nuclear magnetic resonance (NMR) spectroscopy to assess potential residual structural propensities of the intrinsically disordered Nogo-A-Δ20. Using triple resonance experiments, we were able to assign 94% of the non-proline backbone residues. While secondary structure analysis and relaxation measurements highlighted the intrinsically disordered character of Nogo-A-Δ20, three stretches comprising residues 561EAIQESL567, 639EAMNVALKALGT650, and 693SNYSEIAK700 form transient α-helical structures. Interestingly, 561EAIQESL567 is situated directly adjacent to one of the most conserved regions of Nogo-A-Δ20 that contains a binding motif for ß1-integrin. Likewise, 639EAMNVALKALGT650 partially overlaps with the epitope recognized by 11C7, a Nogo-A-neutralizing antibody that promotes functional recovery from spinal cord injury. Diffusion measurements by pulse-field gradient NMR spectroscopy suggest concentration- and oxidation state-dependent dimerisation of Nogo-A-Δ20. Surprisingly, NMR and isothermal titration calorimetry (ITC) data could not validate previously shown binding of extracellular loops of S1PR2 to Nogo-A-Δ20.

The sphingolipid receptor S1PR2 is a receptor for Nogo-a repressing synaptic plasticity.

Nogo-A is a membrane protein of the central nervous system (CNS) restricting neurite growth and synaptic plasticity via two extracellular domains: Nogo-66 and Nogo-A-Δ20. Receptors transducing Nogo-A-Δ20 signaling remained elusive so far. Here we identify the G protein-coupled receptor (GPCR) sphingosine 1-phosphate receptor 2 (S1PR2) as a Nogo-A-Δ20-specific receptor. Nogo-A-Δ20 binds S1PR2 on sites distinct from the pocket of the sphingolipid sphingosine 1-phosphate (S1P) and signals via the G protein G13, the Rho GEF LARG, and RhoA. Deleting or blocking S1PR2 counteracts Nogo-A-Δ20- and myelin-mediated inhibition of neurite outgrowth and cell spreading. Blockade of S1PR2 strongly enhances long-term potentiation (LTP) in the hippocampus of wild-type but not Nogo-A(-/-) mice, indicating a repressor function of the Nogo-A/S1PR2 axis in synaptic plasticity. A similar increase in LTP was also observed in the motor cortex after S1PR2 blockade. We propose a novel signaling model in which a GPCR functions as a receptor for two structurally unrelated ligands, a membrane protein and a sphingolipid. Elucidating Nogo-A/S1PR2 signaling platforms will provide new insights into regulation of synaptic plasticity.

Synthetic microRNA-mediated downregulation of Nogo-A in transgenic rats reveals its role as regulator of synaptic plasticity and cognitive function.

We have generated a transgenic rat model using RNAi and used it to study the role of the membrane protein Nogo-A in synaptic plasticity and cognition. The membrane protein Nogo-A is expressed in CNS oligodendrocytes and subpopulations of neurons, and it is known to suppress neurite growth and regeneration. The constitutively expressed polymerase II-driven transgene was composed of a microRNA-targeting Nogo-A placed into an intron preceding the coding sequence for EGFP, thus quantitatively labeling cells according to intracellular microRNA expression. The transgenic microRNA in vivo efficiently reduced the concentration of Nogo-A mRNA and protein preferentially in neurons. The resulting significant increase in long-term potentiation in both hippocampus and motor cortex indicates a repressor function of Nogo-A in synaptic plasticity. The transgenic rats exhibited prominent schizophrenia-like behavioral phenotypes, such as perseveration, disrupted prepulse inhibition, and strong withdrawal from social interactions. This fast and efficient microRNA-mediated knockdown provides a way to silence gene expression in vivo in transgenic rats and shows a role of Nogo-A in regulating higher cognitive brain functions.