Challenges and complexities in designing cluster headache prevention clinical trials: A narrative review.

OBJECTIVE: To provide a review of challenges in clinical trials for the preventive treatment of cluster headache (CH) and highlight considerations for future studies. BACKGROUND: Current guidelines for preventive treatment of CH are largely based on off-label therapies supported by a limited number of small randomized controlled trials. Guidelines for clinical trial design for CH treatments from the International Headache Society were last issued in 1995. METHODS/RESULTS: Randomized controlled clinical trials were identified in the European and/or United States clinical trial registries with a search term of "cluster headache," and manually reviewed. Cumulatively, there were 27 unique placebo-controlled prevention trials for episodic and/or chronic CH, of which 12 were either ongoing, not yet recruiting, or the status was unknown. Of the remaining 15 trials, 5 were terminated early and 7 of the 10 completed trials enrolled fewer patients than planned or did not report the planned sample size. A systematic search of PubMed was also utilized to identify published manuscripts reporting results from placebo-controlled preventive trials of CH. This search yielded 16 publications, of which 7 were registered. Through critical review of trial data and published manuscripts, challenges and complexities encountered in clinical trials for the preventive treatment of CH were identified. For example, the excruciating pain associated with CH demands a suitably limited baseline duration, rapid treatment efficacy onset, and poses a specific issue regarding duration of investigational treatment period and length of exposure to placebo. In episodic CH, spontaneous remission as part of natural history, and the unpredictability and irregularity of cluster periods across patients present additional key challenges. CONCLUSIONS: Optimal CH trial design should balance sound methodology to demonstrate efficacy of a potential treatment with patient needs and the natural history of the disease, including unique outcome measures and endpoint timings for chronic versus episodic CH.

Tolerability and safety of galcanezumab in patients with chronic cluster headache with up to 15 months of galcanezumab treatment.

OBJECTIVE: The objective of the study was to assess the tolerability and safety of galcanezumab in patients with chronic cluster headache (CH) with up to 15 months of treatment. BACKGROUND: Chronic CH is a highly debilitating disease with a substantial and unmet medical need. METHODS: Patients were randomized to receive placebo or galcanezumab (300 mg) monthly for 12 weeks, followed by an optional 52-week open-label extension and 16-week posttreatment follow-up (washout). This is a secondary analysis and long-term follow-up of a previously conducted clinical trial. The safety analysis included patients who received galcanezumab at any time during the study. Outcomes included adverse events (AEs), discontinuations, laboratory values, vital signs, electrocardiograms (ECGs), and suicidality ratings. RESULTS: A total of 233 patients received at least one galcanezumab dose. The mean exposure was 341 days. Galcanezumab-treated patients were mostly male (n = 169/233; 72.5%) with a mean age of 44.9 (±10.9) years. Treatment-emergent adverse events (TEAEs) were reported by 185 patients (n = 185/233; 79.4%), 23 patients (n = 23/233; 9.9%) reported serious adverse events (SAEs), and 18 patients (n = 18/233; 7.7%) discontinued due to AEs. The SAE CH was reported by three patients. The most common TEAEs (>10%) were nasopharyngitis (n = 41/233; 17.6%) and injection site pain (n = 33/233; 14.2%). 27.5% of patients (n = 64/233) had TEAEs related to injection sites. Likely hypersensitivity events, including injection site rash, injection site urticaria, and injection site hypersensitivity were reported (n = 14/233; 6.0%). There were past histories of suicidal ideation (n = 55/237; 23.2%) and suicidal behavior (n = 9/236; 3.8%). During the study, 15 patients (n = 15/230; 6.5%), seven with previous history, reported suicidal ideation. One patient had a nonfatal suicide attempt during the open-label extension and an aborted attempt during the washout. There were no new safety findings compared with the placebo-controlled treatment period in laboratory values, vital signs, or ECGs. CONCLUSIONS: Galcanezumab 300 mg monthly had a favorable tolerability and safety profile in patients with chronic CH with up to 15 months of treatment.

Evaluation of Cardiovascular Outcomes in Adult Patients With Episodic or Chronic Migraine Treated With Galcanezumab: Data From Three Phase 3, Randomized, Double-Blind, Placebo-Controlled EVOLVE-1, EVOLVE-2, and REGAIN Studies.

OBJECTIVE: Blood pressure (BP), pulse, electrocardiogram (ECG), and clinical cardiovascular (CV) outcomes in patients with episodic or chronic migraine treated for up to 6 months with galcanezumab compared to placebo were evaluated. BACKGROUND: Calcitonin gene-related peptide, a potent microvascular vasodilator, has a hypothesized protective role in CV health. Increased CV risks have been reported in patients with migraine. METHODS: In 2 similarly designed episodic migraine 6-month studies and 1 chronic migraine 3-month study, data from patients randomized (1:1:2) to subcutaneous injection of galcanezumab 120 mg/month (following initial 240 mg loading dose) or 240 mg/month or placebo were pooled. Treatment comparisons for cardiovascular treatment-emergent adverse events (CV TEAE) and categorical and mean changes in BP, pulse, and ECG were evaluated using the Cochran-Mantel-Haenszel test. Mean changes from baseline in BP, pulse, and ECG were evaluated using the analysis of covariance model. RESULTS: Overall, among galcanezumab 120 mg (n = 705) and 240 mg (n = 730), and placebo (n = 1451) groups, the percentage of patients reporting ≥1 CV TEAE was low and was similar between the galcanezumab 120 mg (2.6%; odds ratio [OR] = 0.9; 95% confidence interval [CI]: 0.5,1.5) and galcanezumab 240 mg (3.3%; OR = 1.1; 95% CI: 0.7,1.9), and placebo (2.9%) groups. The frequency of any individual CV TEAE, broad or narrow term, was ≤1.4%. The CV-related serious adverse events that occurred in the galcanezumab 240 mg group (n = 3; acute myocardial infarction, pulmonary embolism, and transient ischemic attack) and placebo group (n = 3; pulmonary embolism, deep vein thrombosis, and myocardial infarction) were not considered treatment related. Four placebo- and 1 galcanezumab-treated patient discontinued due to a CV TEAE. Least squares mean and categorical changes from baseline in BP, pulse, and QT interval corrected using Fridericia's correction were similar across treatment groups. CONCLUSIONS: In this 6-month treatment trial, the percentages of galcanezumab- and placebo-treated patients that reported CV TEAEs or serious adverse events were low and similar between groups with few discontinuations. Thus, no clinically meaningful treatment group differences were observed for changes in BP, pulse, or ECG parameters. Additional longer-term studies in a broader and larger cohort are required to better characterize CV safety.

Effect of age on pharmacokinetics, efficacy, and safety of galcanezumab treatment in adult patients with migraine: results from six phase 2 and phase 3 randomized clinical trials.

BACKGROUND: Migraine clinical profile may change with age, making it necessary to verify that migraine treatments are equally safe and effective in older patients. These analyses evaluated the effects of patient age on the pharmacokinetics (PK), efficacy, and safety of galcanezumab for prevention of migraine. METHODS: Analyses included efficacy data from three double-blind phase 3 clinical trials: two 6-month studies in episodic migraine (EVOLVE-1, EVOLVE-2: N = 1773) and one 3-month study in chronic migraine (REGAIN:N = 1113). Patients were randomized 2:1:1 to placebo, galcanezumab 120 mg, or galcanezumab 240 mg. Safety and PK data included additional phase 2 and phase 3 trials for a larger sample size of patients > 60 years (range = 18-65 for all studies). Subgroup analyses assessed efficacy measures, adverse event (AE) occurrence, and cardiovascular measurement changes by patient age group. Galcanezumab PK were evaluated using a population analysis approach, where age was examined as a potential covariate on apparent clearance (CL/F) and apparent volume of distribution (V/F) of galcanezumab. RESULTS: Numbers of baseline monthly migraine headache days were similar across age groups. There were no statistically significant treatment-by-age group interactions for any efficacy measures, except in episodic migraine studies where older patients appeared to have a larger reduction than younger patients in the number of monthly migraine headache days with acute medication use. Age (18-65) had a minimal effect on CL/F, and no effect on V/F. Galcanezumab-treated patients ≥60 years experienced no clinically meaningful increases in blood pressure and no increased frequency in treatment-emergent AEs, discontinuations due to AEs, serious adverse events (SAEs) overall, or cardiovascular SAEs, compared to age-matched placebo-treated patients. CONCLUSIONS: Age (up to 65 years) does not affect efficacy in migraine prevention and has no clinically meaningful influence on galcanezumab PK to warrant dose adjustment. Furthermore, older galcanezumab-treated patients experienced no increases in frequency of AEs or increases in blood pressure compared with age-matched placebo-treated patients. TRIAL REGISTRATIONS: EVOLVE-1 (NCT02614183, registered 23 November 2015), EVOLVE-2 (NCT02614196, 23 November 2015), REGAIN (NCT02614261, 23 November 2015), ART-01 (NCT01625988, 20 June 2012, ), I5Q-MC-CGAB (NCT02163993, 12 June 2014, ), I5Q-MC-CGAJ (NCT02614287, 23 November 2015, ), all retrospectively registered.

Effects of Galcanezumab on Health-Related Quality of Life and Disability in Patients with Previous Failure of 2-4 Migraine Preventive Medication Categories: Results from a Phase IIIb Randomized, Placebo-Controlled, Multicenter Clinical Trial (CONQUER).

BACKGROUND AND OBJECTIVES: Patients with migraine and prior preventive treatment failures have a significant burden on quality of life and disability. The CONQUER study evaluated the effects of galcanezumab on patient functioning, disability, and health status in episodic or chronic migraine with a previous failure of two to four migraine preventive medication categories. METHODS: Patients with two to four preventive migraine treatment category failures received galcanezumab 120 mg/month (240-mg loading dose) or placebo subcutaneously, for 3 months (double-blind period). In the 3-month open-label period, all patients received galcanezumab irrespective of the treatment received in the double-blind period. Changes in Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQ), Migraine Disability Assessment (MIDAS), and European Quality of Life-5 Dimensions-5 Levels (EQ-5D-5L) scores were assessed. RESULTS: A total of 462 patients were randomized to receive galcanezumab (N = 232) or placebo (N = 230). At month 3, improvement in the MSQ Role-Function-Restrictive score from baseline was significantly greater for galcanezumab (23.19 ± 1.34) vs placebo (10.66 ± 1.33) [p ≤ 0.0001]. Significant improvements in remaining MSQ domains and total MSQ scores were observed (p < 0.0001) during the double-blind period. MIDAS total scores were significantly (p ≤ 0.0001) reduced with galcanezumab (- 21.10 + 3.32) vs placebo (- 3.30 + 3.28). EQ-5D-5L visual analog scale scores improved for galcanezumab (3.40 + 1.31) vs placebo (- 0.09 + 1.29; p = 0.028). During the open-label period, quality of life continued to improve for galcanezumab, with patients previously assigned to placebo reaching similar results. During both study periods, similar findings were reported in subpopulations with episodic migraine and chronic migraine. CONCLUSIONS: Galcanezumab significantly improved functioning and reduced disability in patients with episodic migraine and chronic migraine and two to four migraine preventive treatment category failures. CLINICAL TRIAL REGISTRATION: NCT03559257, registration date: 6 June, 2018.

Central nervous system histoplasmosis: Multicenter retrospective study on clinical features, diagnostic approach and outcome of treatment.

Central nervous system (CNS) involvement occurs in 5 to 10% of individuals with disseminated histoplasmosis. Most experience has been derived from small single center case series, or case report literature reviews. Therefore, a larger study of central nervous system (CNS) histoplasmosis is needed in order to guide the approach to diagnosis, and treatment.A convenience sample of 77 patients with histoplasmosis infection of the CNS was evaluated. Data was collected that focused on recognition of infection, diagnostic techniques, and outcomes of treatment.Twenty nine percent of patients were not immunosuppressed. Histoplasma antigen, or anti-Histoplasma antibodies were detected in the cerebrospinal fluid (CSF) in 75% of patients. One year survival was 75% among patients treated initially with amphotericin B, and was highest with liposomal, or deoxycholate formulations. Mortality was higher in immunocompromised patients, and patients 54 years of age, or older. Six percent of patients relapsed, all of whom had the acquired immunodeficiency syndrome (AIDS), and were poorly adherent with treatment.While CNS histoplasmosis occurred most often in immunocompromised individuals, a significant proportion of patients were previously, healthy. The diagnosis can be established by antigen, and antibody testing of the CSF, and serum, and antigen testing of the urine in most patients. Treatment with liposomal amphotericin B (AMB-L) for at least 1 month; followed by itraconazole for at least 1 year, results in survival among the majority of individuals. Patients should be followed for relapse for at least 1 year, after stopping therapy.

An Efficient and Reliable Statistical Method for Estimating Functional Connectivity in Large Scale Brain Networks Using Partial Correlation.

Currently, network-oriented analysis of fMRI data has become an important tool for understanding brain organization and brain networks. Among the range of network modeling methods, partial correlation has shown great promises in accurately detecting true brain network connections. However, the application of partial correlation in investigating brain connectivity, especially in large-scale brain networks, has been limited so far due to the technical challenges in its estimation. In this paper, we propose an efficient and reliable statistical method for estimating partial correlation in large-scale brain network modeling. Our method derives partial correlation based on the precision matrix estimated via Constrained L1-minimization Approach (CLIME), which is a recently developed statistical method that is more efficient and demonstrates better performance than the existing methods. To help select an appropriate tuning parameter for sparsity control in the network estimation, we propose a new Dens-based selection method that provides a more informative and flexible tool to allow the users to select the tuning parameter based on the desired sparsity level. Another appealing feature of the Dens-based method is that it is much faster than the existing methods, which provides an important advantage in neuroimaging applications. Simulation studies show that the Dens-based method demonstrates comparable or better performance with respect to the existing methods in network estimation. We applied the proposed partial correlation method to investigate resting state functional connectivity using rs-fMRI data from the Philadelphia Neurodevelopmental Cohort (PNC) study. Our results show that partial correlation analysis removed considerable between-module marginal connections identified by full correlation analysis, suggesting these connections were likely caused by global effects or common connection to other nodes. Based on partial correlation, we find that the most significant direct connections are between homologous brain locations in the left and right hemisphere. When comparing partial correlation derived under different sparse tuning parameters, an important finding is that the sparse regularization has more shrinkage effects on negative functional connections than on positive connections, which supports previous findings that many of the negative brain connections are due to non-neurophysiological effects. An R package "DensParcorr" can be downloaded from CRAN for implementing the proposed statistical methods.

Network-based characterization of brain functional connectivity in Zen practitioners.

In the last decade, a number of neuroimaging studies have investigated the neurophysiological effects associated with contemplative practices. Meditation-related changes in resting state functional connectivity (rsFC) have been previously reported, particularly in the default mode network, frontoparietal attentional circuits, saliency-related regions, and primary sensory cortices. We collected functional magnetic resonance imaging data from a sample of 12 experienced Zen meditators and 12 meditation-naïve matched controls during a basic attention-to-breathing protocol, together with behavioral performance outside the scanner on a set of computerized neuropsychological tests. We adopted a network system of 209 nodes, classified into nine functional modules, and a multi-stage approach to identify rsFC differences in meditators and controls. Between-group comparisons of modulewise FC, summarized by the first principal component of the relevant set of edges, revealed important connections of frontoparietal circuits with early visual and executive control areas. We also identified several group differences in positive and negative edgewise FC, often involving the visual, or frontoparietal regions. Multivariate pattern analysis of modulewise FC, using support vector machine (SVM), classified meditators, and controls with 79% accuracy and selected 10 modulewise connections that were jointly prominent in distinguishing meditators and controls; a similar SVM procedure based on the subjects' scores on the neuropsychological battery yielded a slightly weaker accuracy (75%). Finally, we observed a good correlation between the across-subject variation in strength of modulewise connections among frontoparietal, executive, and visual circuits, on the one hand, and in the performance on a rapid visual information processing test of sustained attention, on the other. Taken together, these findings highlight the usefulness of employing network analysis techniques in investigating the neural correlates of contemplative practices.