Comparative effectiveness of erenumab versus rimegepant for migraine prevention using matching-adjusted indirect comparison.

Aim: To compare the efficacy of erenumab versus rimegepant as preventive treatment for patients with episodic and chronic migraine using an anchor-based matching-adjusted indirect comparison. Methods: Patients from two phase II/III trials for erenumab (NCT02066415 and NCT02456740) were pooled and weighted to match on the baseline effect modifiers (age, sex, race, baseline monthly migraine days [MMDs], and history of chronic migraine [CM]) reported in the phase II/III trial for rimegepant (NCT03732638). Four efficacy outcomes were compared between the two erenumab regimens (70 mg and 140 mg) and rimegepant, including changes in MMDs from baseline to month 1 and month 3, changes in Migraine-Specific Quality of Life Questionnaire role function - restrictive domain score from baseline to month 3, and change in disability from baseline to Month 3. Results: Compared with rimegepant, erenumab 70 mg was associated with a statistically significant reduction in MMDs at month 3 (-0.90 [-1.76, -0.03]; p = 0.042) and erenumab 140 mg was associated with statistically significant reductions in MMDs at month 1 (-0.94 [-1.70, -0.19]; p = 0.014) and month 3 (-1.28 [-2.17, -0.40]; p = 0.005). The erenumab regimens also had numerical advantages over rimegepant for other efficacy outcomes. Conclusion: In the present study, we found that erenumab had a more favorable efficacy profile than rimegepant in reducing MMDs at month 1 and month 3 for migraine prevention. These results may help with decision-making in clinical practice and can be further validated in future clinical trials or real-world studies.

Serum tau protein elevation in migraine: a cross-sectional case-control study.

BACKGROUND: Migraine is a disorder associated with neuropeptide release, pain and inflammation. Tau protein has recently been linked to inflammatory diseases and can be influenced by neuropeptides such as CGRP, a key neurotransmitter in migraine. Here, we report serum concentrations of total-tau protein in migraine patients and healthy controls. METHODS: In this cross-sectional study, interictal blood samples from n = 92 patients with episodic migraine (EM), n = 93 patients with chronic migraine (CM), and n = 42 healthy matched controls (HC) were studied. We assessed serum total-tau protein (t-tau) and for comparison neurofilament light chain protein (NfL), glial fibrillary acidic protein (GFAP), and ubiquitin carboxy-terminal hydrolase L (UCH-L1) concentrations using the Neurology 4-plex kit, on a single molecule array HD-X Analyzer (Quanterix Corp Lexington, MA). Matched serum/cerebrospinal fluid (CSF) samples were used for post-hoc evaluations of a central nervous system (CNS) source of relevant findings. We applied non-parametric tests to compare groups and assess correlations. RESULTS: Serum t-tau concentrations were elevated in EM [0.320 (0.204 to 0.466) pg/mL] and CM [0.304 (0.158 to 0.406) pg/mL] patients compared to HC [0.200 (0.114 to 0.288) pg/mL] (p = 0.002 vs. EM; p = 0.025 vs. CM). EM with aura [0.291 (0.184 to 0.486 pg/mL); p = 0.013] and EM without aura [0.332 (0.234 to 0.449) pg/mL; p = 0.008] patients had higher t-tau levels than HC but did not differ between each other. Subgroup analysis of CM with/without preventive treatment revealed elevated t-tau levels compared to HC only in the non-prevention group [0.322 (0.181 to 0.463) pg/mL; p = 0.009]. T-tau was elevated in serum (p = 0.028) but not in cerebrospinal fluid (p = 0.760). In contrast to t-tau, all proteins associated with cell damage (NfL, GFAP, and UCH-L1), did not differ between groups. DISCUSSION: Migraine is associated with t-tau elevation in serum but not in the CSF. Our clinical study identifies t-tau as a new target for migraine research.

Real-world evidence data on the monoclonal antibody erenumab in migraine prevention: perspectives of treating physicians in Germany.

BACKGROUND: Erenumab, the first-in-class fully human monoclonal antibody targeting the calcitonin gene-related peptide receptor, was shown to be efficacious and safe for the prophylactic treatment of migraine in adults in randomized clinical trials. Large-scale, real-world evidence in multi-centre settings is still needed to confirm these results. Erenumab patient profiles outside clinical trials and physicians' treatment patterns, as well as data from patients treated in Germany, a severely impacted population, are not published yet. METHODS: TELESCOPE was a multi-centre survey gathering real-world data from 45 German headache centres between July 2019 and December 2019. The project consisted of two parts. In the first part, treating physicians shared their experiences on current erenumab treatment with regard to patient profiles, treatment patterns and treatment responses. In the second part, a retrospective chart review was conducted of 542 migraine patients treated with erenumab for at least three months. Treatment responses focused on various aspects of patients' quality of life. RESULTS: The analysis of 542 patients' charts revealed that three-month treatment with erenumab significantly reduced monthly headaches, migraine and acute medication days. Furthermore, headache intensity and frequency were reduced in over 75 % and accompanying aura in 35 % of patients. The clinical global impression scale revealed a general improvement in 91 % of patients. According to the treating physicians' professional judgement, 83 % of patients responded to erenumab and 80 % were satisfied with the treatment. Physicians evaluated restricted quality of life, the number of monthly migraine days and previous, prophylactic treatments as the main components of the current patient profile for monoclonal antibody recipients. Based on the assessment of physicians, erenumab reduced migraine symptoms in 65 % and increased quality of life in more than 75 % of their patients. CONCLUSIONS: TELESCOPE confirms positive treatment responses with erenumab shown in clinical trials in a real-world multi-centre setting. The results show consistently positive experiences of physicians utilizing erenumab in clinical practice and underline that therapy with this monoclonal antibody is effective in migraine patients, particular in those, who have failed several prophylactic therapies.

The cGMP-Dependent Protein Kinase 2 Contributes to Cone Photoreceptor Degeneration in the Cnga3-Deficient Mouse Model of Achromatopsia.

Mutations in the CNGA3 gene, which encodes the A subunit of the cyclic guanosine monophosphate (cGMP)-gated cation channel in cone photoreceptor outer segments, cause total colour blindness, also referred to as achromatopsia. Cones lacking this channel protein are non-functional, accumulate high levels of the second messenger cGMP and degenerate over time after induction of ER stress. The cell death mechanisms that lead to loss of affected cones are only partially understood. Here, we explored the disease mechanisms in the Cnga3 knockout (KO) mouse model of achromatopsia. We found that another important effector of cGMP, the cGMP-dependent protein kinase 2 (Prkg2) is crucially involved in cGMP cytotoxicity of cones in Cnga3 KO mice. Virus-mediated knockdown or genetic ablation of Prkg2 in Cnga3 KO mice counteracted degeneration and preserved the number of cones. Analysis of markers of endoplasmic reticulum stress and unfolded protein response confirmed that induction of these processes in Cnga3 KO cones also depends on Prkg2. In conclusion, we identified Prkg2 as a novel key mediator of cone photoreceptor degeneration in achromatopsia. Our data suggest that this cGMP mediator could be a novel pharmacological target for future neuroprotective therapies.

ORCA study: real-world versus reading centre assessment of disease activity of neovascular age-related macular degeneration (nAMD).

BACKGROUND/AIMS: The prospective, non-interventional ORCA module of the OCEAN study (Observation of Treatment Patterns with Lucentis in Approved Indications) evaluated the qualiy of spectral domain-optical coherence tomography (SD-OCT) image interpretation and treatment decisions by clinicians in Germany and the impact on visual outcomes over 24 months in patients with neovascular age-related macular degeneration (nAMD). METHODS: 2286 SD-OCT scans of 205 eyes were independently evaluated by clinicians and reading centres (RCs) regarding signs of choroidal neovascularisation (CNV) activity, including presence of intraretinal fluid, subretinal fluid, and/or increase in pigment epithelial detachments. Agreement between clinicians and RCs was calculated. Treatment decisions by clinicians and the impact on treatment outcomes were evaluated. RESULTS: CNV activity was detected by RCs on 1578 scans (69.0%) and by clinicians on 1392 scans (60.9%), with agreement in 74.9% of cases. Of the 1578 scans with RC detected CNV activity, anti-vascular endothelial growth factor injections were performed by clinicians in only 35.5% (560/1578). In 19.7% of cases (311/1578), lack of treatment was justified by patients request, termination criteria or chronic cystoid spaces without other signs for CNV activity. In 44.8% of cases (707/1578) with RC detected CNV activity, clinicians claimed no treatment was necessary despite having correctly detected CNV activity in about 2/3 of these cases. In 34% of cases with presumed undertreatment, visual acuity declined in the following visit. CONCLUSION: Although broad agreement on CNV activity parameters was observed between clinicians and RCs, correct identification of CNV activity did not always lead to the initiation of (re-)treatment. To preserve vision over time, correct interpretation of SD-OCT scans and careful retreatment decisions are required. TRIAL REGISTRATION NUMBER: NCT02194803.

A microRNA signature of toxic extrasynaptic N-methyl-D-aspartate (NMDA) receptor signaling.

The cellular consequences of N-Methyl-D-Aspartate receptor (NMDAR) stimulation depend on the receptors' subcellular localization. Synaptic NMDARs promote plasticity and survival whereas extrasynaptic NMDARs mediate excitotoxicity and contribute to cell death in neurodegenerative diseases. The mechanisms that couple activation of extrasynaptic NMDARs to cell death remain incompletely understood. We here show that activation of extrasynaptic NMDARs by bath application of NMDA or L-glutamate leads to the upregulation of a group of 19 microRNAs in cultured mouse hippocampal neurons. In contrast, none of these microRNAs is induced upon stimulation of synaptic activity. Increased microRNA expression depends on the pri-miRNA processing enzyme Drosha, but not on de novo gene transcription. These findings suggest that toxic NMDAR signaling involves changes in the expression levels of particular microRNAs.

Real-World Data: Ranibizumab Treatment For Retinal Vein Occlusion In The OCEAN Study.

PURPOSE: The non-interventional OCEAN study (NCT02194803) evaluated frequency and monitoring of ranibizumab injections for retinal vein occlusion (RVO) in routine practice in Germany. METHODS: RVO patients (including branch and central RVO (BRVO/CRVO)) receiving ranibizumab were included. Best-corrected visual acuity (BCVA) testing, imaging and treatment were performed at the investigators' discretion and documented over 24 months. RESULTS: Overall, 744 RVO patients (27% BRVO, 16% CRVO, remaining unspecified RVO) were included. For 74% of patients, data were available for the 12-month visit and for 56% for the 24-month visit. Mean baseline BCVA was 52.0 Early Treatment for Diabetic Retinopathy Study (ETDRS) letters (BRVO: 55.9, CRVO: 43.9). BCVA improved rapidly within the first 3 months, reaching 64.3 letters at 12 months and 64.7 at 24 months. CRVO patients showed less improvement than those with BRVO. Patients received a median of 4 (5) injections over 12 (24) months, with 100% of patients receiving injections at baseline, 70% at Month 1 and 81% at Month 2. Overall, 40% of patients demonstrated a ≥15 letter increase within the first 3 months (42% BRVO, 46% CRVO). Patients with low initial BCVA (<50 letters) showed greater improvement than patients with higher baseline BCVA. Due to considerable loss to follow-up, the number of injections and optical coherence tomography (OCT) examinations were not associated with the change in BCVA. CONCLUSION: Patients with RVO in routine practice in Germany received fewer injections and fewer OCT examinations than in clinical trials. CRVO patients showed less and later improvement compared to BRVO patients.

Intravitreal Ranibizumab Therapy for Diabetic Macular Edema in Routine Practice: Two-Year Real-Life Data from a Non-interventional, Multicenter Study in Germany.

INTRODUCTION: The prospective, non-interventional OCEAN study examined the use of intravitreal ranibizumab injections for the treatment of diabetic macular oedema (DME) in a real-world setting in Germany. METHODS: Adults with DME receiving ≥ 1 ranibizumab (0.5 mg) injections were recruited by 250 ophthalmologists. Best-corrected visual acuity (VA) testing, imaging and treatments were performed according to the investigators' routine practice and documented over 24 months. RESULTS: The full analysis set included 1226 participants. Mean baseline VA was 60.6 [95% CI: 59.7; 61.5] Early Treatment Diabetic Retinopathy Study letters. VA improved by ≥ 15 letters in 21.5% and 23.5% of the participants at 12 months and 24 months, respectively. They received a mean number of 4.42 [95% CI: 4.30; 4.54] injections in the first year and 5.52 [95% CI: 5.32; 5.73] injections over 24 months, which was markedly lower than in clinical trials. Only 33.4% of the participants received an upload with four initial monthly injections as recommended by the German ophthalmologic societies. Time-to-event analyses that account for missing data inherent to a non-interventional study design demonstrated that participants receiving ≥ 7 injections in the first year had a faster response, but the duration of the response was shorter compared to the subgroups receiving 1-3 and 4-6 injections. Serious adverse events were reported for 143/1250 (11.4%) participants in the safety population. CONCLUSION: Under-treatment is a major problem of DME anti- vascular endothelial growth factor therapy under real life conditions. Despite fewer injections given compared to randomised controlled trials with a consequently reduced overall mean visual gain, a profound functional improvement (≥ 15 letters) was achieved over 2 years in 23.5% of eyes with DME. TRIAL REGISTRATION NUMBER: NCT02194803, ClinicalTrials.gov. FUNDING: Novartis Pharma GmbH, Nuremberg, Germany.

Early Microglia Activation Precedes Photoreceptor Degeneration in a Mouse Model of CNGB1-Linked Retinitis Pigmentosa.

Retinitis pigmentosa (RP) denotes a family of inherited blinding eye diseases characterized by progressive degeneration of rod and cone photoreceptors in the retina. In most cases, a rod-specific genetic defect results in early functional loss and degeneration of rods, which is followed by degeneration of cones and loss of daylight vision at later stages. Microglial cells, the immune cells of the central nervous system, are activated in retinas of RP patients and in several RP mouse models. However, it is still a matter of debate whether activated microglial cells may be responsible for the amplification of the typical degenerative processes. Here, we used Cngb1-/- mice, which represent a slow degenerative mouse model of RP, to investigate the extent of microglia activation in retinal degeneration. With a combination of FACS analysis, immunohistochemistry and gene expression analysis we established that microglia in the Cngb1-/- retina were already activated in an early, predegenerative stage of the disease. The evidence available so far suggests that early retinal microglia activation represents a first step in RP, which might initiate or accelerate photoreceptor degeneration.

In Vivo Analysis of Disease-Associated Point Mutations Unveils Profound Differences in mRNA Splicing of Peripherin-2 in Rod and Cone Photoreceptors.

Point mutations in peripherin-2 (PRPH2) are associated with severe retinal degenerative disorders affecting rod and/or cone photoreceptors. Various disease-causing mutations have been identified, but the exact contribution of a given mutation to the clinical phenotype remains unclear. Exonic point mutations are usually assumed to alter single amino acids, thereby influencing specific protein characteristics; however, they can also affect mRNA splicing. To examine the effects of distinct PRPH2 point mutations on mRNA splicing and protein expression in vivo, we designed PRPH2 minigenes containing the three coding exons and relevant intronic regions of human PRPH2. Minigenes carrying wild type PRPH2 or PRPH2 exon 2 mutations associated with rod or cone disorders were expressed in murine photoreceptors using recombinant adeno-associated virus (rAAV) vectors. We detect three PRPH2 splice isoforms in rods and cones: correctly spliced, intron 1 retention, and unspliced. In addition, we show that only the correctly spliced isoform results in detectable protein expression. Surprisingly, compared to rods, differential splicing leads to lower expression of correctly spliced and higher expression of unspliced PRPH2 in cones. These results were confirmed in qRT-PCR experiments from FAC-sorted murine rods and cones. Strikingly, three out of five cone disease-causing PRPH2 mutations profoundly enhanced correct splicing of PRPH2, which correlated with strong upregulation of mutant PRPH2 protein expression in cones. By contrast, four out of six PRPH2 mutants associated with rod disorders gave rise to a reduced PRPH2 protein expression via different mechanisms. These mechanisms include aberrant mRNA splicing, protein mislocalization, and protein degradation. Our data suggest that upregulation of PRPH2 levels in combination with defects in the PRPH2 function caused by the mutation might be an important mechanism leading to cone degeneration. By contrast, the pathology of rod-specific PRPH2 mutations is rather characterized by PRPH2 downregulation and impaired protein localization.

Quick and reliable method for retina dissociation and separation of rod photoreceptor perikarya from adult mice.

A pure and abundant population of adult rod perikarya can be exploited in different studies concerning nuclear functions such as gene expression analyses which aim at elucidating the relationship between cell type and disease [1]. Sorting is based either on specific cell-surface markers or fluorescently labeled reporter proteins. Here, we describe a simple and reliable method for separation of rod photoreceptor perikarya without the use of staining procedures or transgenic mice. This method is limited, however, to sorting rod photoreceptors from adult mouse retina. Mature rods possess an inverted nuclear architecture which is determined by the optical functions of these nuclei [2]. The high backscatter of heterochromatin in the core of the nucleus can be used as a selection criterion for FAC-sorting by forward and sideward scatter. •The procedure for retina dissociation using the Papain Dissociation System (Wothington Biochemical Corporation) was optimized.•An easy to follow step-by-step protocol for retina dissociation was devised.•Rod perikarya were FAC-sorted by forward and sideward scatter based solely on the high backscatter of heterochromatin in their nuclei.