Phase 3 randomized, placebo-controlled study of galcanezumab in patients with chronic cluster headache: Results from 3-month double-blind treatment

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.

Galcanezumab effectiveness on comorbid cluster headache and chronic migraine: a prospective case series

BACKGROUND

Cluster headache (CH) and migraine are recurrent painful primary cephalalgies, typically with different clinical appearance and some shared features, such as unilateral pain, common triggers and response to triptans and/or monoclonal antibodies against the calcitonin gene-related peptide (CGRP) pathway. Common pathophysiological mechanisms are proposed in CH and migraine, including the role of the trigeminal-vascular system with its most representative neuropeptide, CGRP. Very few case series have been conducted so far investigating anti-CGRP treatments in patients with comorbid CH and migraine, and no cases have been reported which assess both CH and chronic migraine outcomes.

CASE SERIES

We describe 4 patients with both chronic migraine and cluster headache, with or without failure to preventive medications. Galcanezumab (240 mg loading dose, followed by 120 mg monthly) was used for at least a 3-month treatment, demonstrating improvement in both migraine and CH outcomes (i.e. migraine days, CH attacks, Headache Impact Test -6 item score, acute medications use), achieving sustained clinical benefit. No adverse events were reported.

DISCUSSION AND CONCLUSION

Taking into account the role of CGRP in migraine and CH pathophysiology, a usually well-tolerated treatment with CGRP blockade could be a rationale-based option to treat patients with coexisting chronic migraine and cluster headache. Additional studies are needed to assess the role of anti-CGRP drugs in episodic and chronic CH treatment, as well as to establish correct timing and patient prerequisites to begin therapy.

Cluster Headache Pathophysiology—A Disorder of Network Excitability?

Patients’ accounts of cluster headache attacks, ictal restlessness, and electrophysiological studies suggest that the pathophysiology involves Aδ-fibre nociceptors and the network processing their input. Continuous activity of the trigeminal autonomic reflex throughout the in-bout period results in central sensitization of these networks in many patients. It is likely that several factors force circadian rhythmicity upon the disease. In addition to sensitization, circadian changes in pain perception and autonomic innervation might influence the excitability of the trigeminal cervical complex. Summation of several factors influencing pain perception might render neurons vulnerable to spontaneous depolarization, particularly at the beginning of rapid drops of the pain threshold (“summation headache”). In light of studies suggesting an impairment of short-term synaptic plasticity in CH patients, we suggest that the physiologic basis of CH attacks might be network overactivity—similarly to epileptic seizures. Case reports documenting cluster-like attacks support the idea of distinct factors being transiently able to induce attacks and being relevant in the pathophysiology of the disorder. A sustained and recurring proneness to attacks likely requires changes in the activity of other structures among which the hypothalamus is the most probable candidate.

Benefit-Risk Assessment of Galcanezumab Versus Placebo for the Treatment of Episodic and Chronic Migraine Using the Metrics of Number Needed to Treat and Number Needed to Harm

INTRODUCTION

Subcutaneous galcanezumab was an effective, well-tolerated preventive treatment for adults with episodic (EM) or chronic migraine (CM) in 4 phase 3 randomized controlled trials: EVOLVE-1, EVOLVE-2, REGAIN, and CONQUER. Number needed to treat (NNT) and to harm (NNH) are metrics of effect size used to evaluate benefit-risk profiles. This study evaluated NNT, NNH, and benefit-risk profiles (measured as likelihood to be helped or harmed, LHH) of galcanezumab 120 mg versus placebo in patients with EM or CM.

METHODS

Primary efficacy outcomes were responses defined as ≥ 30%, ≥ 50%, and ≥ 75% reductions from baseline in number of monthly migraine headache days in patients with EM (EVOLVE-1; EVOLVE-2; CONQUER) and CM (REGAIN; CONQUER); corresponding NNTs to achieve respective responses; and corresponding NNHs for discontinuations due to adverse events (DCAEs) among the safety population. Secondary efficacy outcomes were responses for patients with ≥ 2 failed prior preventive treatments due to lack of efficacy and/or for tolerability reasons. All LHHs were based on ≥ 50% response and DCAEs.

RESULTS

During double-blind treatment periods with galcanezumab 120 mg, NNT to achieve ≥ 30% and ≥ 50% responses ranged from 4 to 10 and NNT to achieve ≥ 75% responses ranged from 5 to 23 in individual trials. NNH ranged from 93 to 1000, while LHH ranged from 18.6 to 104.6. NNTs were generally more robust among patients with EM than with CM; however, in patients with failure of ≥ 2 prior preventive treatments, NNTs to achieve ≥ 30% and ≥ 50% responses were similar between patients with CM and EM. NNHs were imputed as 1000 for both migraine types. Resulting LHHs were 178.8 (EM) and 127 (CM).

CONCLUSION

Across 4 trials, galcanezumab 120 mg demonstrated a favorable benefit-risk profile versus placebo, based on low NNTs to achieve response and high NNHs associated with DCAEs. LHH values consistently far exceeded 1.

TRIAL REGISTRATION NUMBERS

EVOLVE-1: ClinicalTrials.gov identifier, NCT02614183; EVOLVE-2: ClinicalTrials.gov identifier, NCT02614196; REGAIN: ClinicalTrials.gov identifier, NCT02614261; CONQUER: ClinicalTrials.gov identifier, NCT03559257.

Safety and efficacy of occipital nerve stimulation for attack prevention in medically intractable chronic cluster headache (ICON): a randomised, double-blind, multicentre, phase 3, electrical dose-controlled trial

BACKGROUND

Occipital nerve stimulation (ONS) has shown promising results in small uncontrolled trials in patients with medically intractable chronic cluster headache (MICCH). We aimed to establish whether ONS could serve as an effective treatment for patients with MICCH.

METHODS

The ONS in MICCH (ICON) study is an investigator-initiated, international, multicentre, randomised, double-blind, phase 3, electrical dose-controlled clinical trial. The study took place at four hospitals in the Netherlands, one hospital in Belgium, one in Germany, and one in Hungary. After 12 weeks' baseline observation, patients with MICCH, at least four attacks per week, and history of being non-responsive to at least three standard preventive drugs, were randomly allocated (at a 1:1 ratio using a computer-generated permuted block) to 24 weeks of occipital nerve stimulation at either 100% or 30% of the individually determined range between paraesthesia threshold and near-discomfort (double-blind study phase). Because ONS causes paraesthesia, preventing masked comparison versus placebo, we compared high-intensity versus low-intensity ONS, which are hypothesised to cause similar paraesthesia, but with different efficacy. In weeks 25-48, participants received individually optimised open-label ONS. The primary outcome was the weekly mean attack frequency in weeks 21-24 compared with baseline across all patients and, if a decrease was shown, to show a group-wise difference. The trial is closed to recruitment (ClinicalTrials.gov NCT01151631).

FINDINGS

Patients were enrolled between Oct 12, 2010, and Dec 3, 2017. We enrolled 150 patients and randomly assigned 131 (87%) to treatment; 65 (50%) patients to 100% ONS and 66 (50%) to 30% ONS. One of the 66 patients assigned to 30% ONS was not implanted and was therefore excluded from the intention-to-treat analysis. Because the weekly mean attack frequencies at baseline were skewed (median 15·75; IQR 9·44 to 24·75) we used log transformation to analyse the data and medians to present the results. Median weekly mean attack frequencies in the total population decreased from baseline to 7·38 (2·50 to 18·50; p<0·0001) in weeks 21-24, a median change of -5·21 (-11·18 to -0·19; p<0·0001) attacks per week. In the 100% ONS stimulation group, mean attack frequency decreased from 17·58 (9·83 to 29·33) at baseline to 9·50 (3·00 to 21·25) at 21-24 weeks (median change from baseline -4·08, -11·92 to -0·25), and for the 30% ONS stimulation group, mean attack frequency decreased from 15·00 (9·25 to 22·33) to 6·75 (1·50 to 16·50; -6·50, -10·83 to -0·08). The difference in median weekly mean attack frequency between groups at the end of the masked phase in weeks 21-24 was -2·42 (95% CI -5·17 to 3·33). In the masked study phase, 129 adverse events occurred with 100% ONS and 95 occurred with 30% ONS. None of the adverse events was unexpected but 17 with 100% ONS and eight with 30% ONS were labelled as serious, given they required brief hospital admission for minor hardware-related issues. The most common adverse events were local pain, impaired wound healing, neck stiffness, and hardware damage.

INTERPRETATION

In patients with MICCH, both 100% ONS intensity and 30% ONS intensity substantially reduced attack frequency and were safe and well tolerated. Future research should focus on optimising stimulation protocols and disentangling the underlying mechanism of action.

FUNDING

The Netherlands Organisation for Scientific Research, the Dutch Ministry of Health, the NutsOhra Foundation from the Dutch Health Insurance Companies, and Medtronic.

Monoclonal Antibodies Targeting CGRP: From Clinical Studies to Real-World Evidence-What Do We Know So Far?

Now more than ever is the time of monoclonal antibody use in neurology. In headaches, disease-specific and mechanism-based treatments existed only for symptomatic management of migraines (i.e., triptans), while the standard prophylactic anti-migraine treatments consist of non-specific and repurposed drugs that share limited safety profiles and high risk for interactions with other medications, resulting in rundown adherence rates. Recent advances in headache science have increased our understanding of the role of calcitonin gene relate peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) pathways in cephalic pain neurotransmission and peripheral or central sensitization, leading to the development of monoclonal antibodies (mAbs) or small molecules targeting these neuropeptides or their receptors. Large scale randomized clinical trials confirmed that inhibition of the CGRP system attenuates migraine, while the PACAP mediated nociception is still under scientific and clinical investigation. In this review, we provide the latest clinical evidence for the use of anti-CGRP in migraine prevention with emphasis on efficacy and safety outcomes from Phase III and real-world studies.

Cluster Headache: What's New?

Background

Cluster headache is a highly disabling primary headache disorder which is widely described as the most painful condition a human can experience.

Aim

To provide an overview of the clinical characteristics, epidemiology, risk factors, differential diagnosis, pathophysiology and treatment options of cluster headache, with a focus on recent developments in the field.

Methods

Structured review of the literature on cluster headache.

Results

Cluster headache affects approximately one in 1000 of the population. It is characterised by attacks of severe unilateral head pain associated with ipsilateral cranial autonomic symptoms, and the tendency for attacks to occur with circadian and circannual periodicity. The pathophysiology of cluster headache and other primary headache disorders has recently become better understood and is thought to involve the hypothalamus and trigeminovascular system. There is good quality evidence for acute treatment of attacks with parenteral triptans and high flow oxygen; preventive treatment with verapamil; and transitional treatment with oral corticosteroids or greater occipital nerve injection. New pharmacological and neuromodulation therapies have recently been developed.

Conclusion

Cluster headache causes distinctive symptoms, which once they are recognised can usually be managed with a variety of established treatments. Recent pathophysiological understanding has led to the development of newer pharmacological and neuromodulation therapies, which may soon become established in clinical practice.

Current advances in the management of cluster headaches

Introduction: Cluster headache (CH) is probably the most severe idiopathic pain condition, yet its current medical management remains poor.Areas covered: Only repurpose medicines are currently in use for the prevention of CH, partially because the pathophysiology of the condition is still elusive. In this article we performed a systematic review to evaluate the evidence for efficacy of the currently available or emerging treatments for CH.Expert opinion: We found several ongoing randomized clinical trials testing prophylactic treatments for CH and only few for the standard ones. Recent data from randomized trials with monoclonal antibodies targeting the calcitonin gene related peptide pathway (anti-CGRP mAbs) are controversial, although its role in the pathogenesis of the condition is well documented. This inconsistency may depict inadequacies in clinical trial designing. Anti-CGRP mAbs and antagonists of pituitary adenylate cyclase-activating polypeptide (PACAP) along with neuromodulation techniques, are curing the necessary valuable evidence that could illuminate the therapeutical future for cluster headache. Orexin pathway is another attractive target for CH treatment. To improve the evidence for efficacy, we further propose that the design of the clinical trials for CH needs to be radically reviewed to allow more patients to participate.

Cluster headache and TACs: state of the art

Cluster headache (CH), paroxysmal hemicrania (PH), short-lasting unilateral neuralgiform headache attacks (including SUNCT and SUNA), and hemicrania continua (HC) compose the group of trigeminal autonomic cephalalgias (TACs). Here, we review the recent advances in the field and summarize the current knowledge about the origin of these headaches. Similar to the other primary headaches, the pathogenesis is still much obscure. However, advances are being made in both animal models and humans studies. Three structures clearly appear to be crucial in the pathophysiology of TACs: the trigeminal nerve, the facial parasympathetic system, and the hypothalamus. The physiologic and pathologic functioning of each of these elements and their interactions is being progressively clarified, but critical questions are still open.

Cluster Headache: A Review and Update in Treatment

PURPOSE OF REVIEW

The treatment of cluster headache has evolved to include a handheld neuromodulation device and a monoclonal antibody in addition to more traditional agents.

RECENT FINDINGS

Galcanezumab is an approved treatment for episodic cluster headache. The non-invasive vagal nerve stimulator has been shown to be effective as a treatment for episodic cluster headache. Dedicated pituitary imaging may not be necessary with a normal MRI of the brain. Cluster headache is the most common trigeminal-autonomic cephalalgia, characterized by unilateral, frequent, debilitating attacks associated with ipsilateral autonomic symptoms. Attacks have a circadian and, often, seasonal pattern with periods of remission that can last months to years in episodic patients. Though a rare disease, an increasing number of studies have revealed novel targets for treatment. Treatment in cluster headache should focus on early intervention to reduce frequency of attacks and the length of the cycle, which improves outcomes and disability. Acute therapy is used to treat attacks, while bridging and preventive therapies are combined to reduce cycle length. Case 1: A 43-year-old man presents with the chief complaint of severe headaches. Upon general examination, he seems uncomfortable, agitated, and exhausted. He states that he hasn't "slept in over a week because of debilitating headaches." His headaches start around the same time every night: when he lays down to go to sleep. The pain is described as sharp, like a "hot poker" to his left eye. His partner has noticed that his eye droops and turns red when the pain starts. The attacks come on abruptly and prevent him from sleeping. The severe pain lasts 30 to 45 min, but he has mild-to-moderate pain that lingers for the rest of the night. He has seen his primary care physician, an allergist, and an ear, nose, and throat (ENT) specialist before coming to see a neurologist. Similar headaches occurred last year during the month of October as well. On further questioning, he reports that these headache attacks have been occurring almost yearly for the past 7 years. Each year, these headaches come on as the weather is changing and occur on a nightly basis for about 3 to 4 weeks.

Cluster headache pathophysiology - insights from current and emerging treatments

Cluster headache is a debilitating primary headache disorder that affects approximately 0.1% of the population worldwide. Cluster headache attacks involve severe unilateral pain in the trigeminal distribution together with ipsilateral cranial autonomic features and a sense of agitation. Acute treatments are available and are effective in just over half of the patients. Until recently, preventive medications were borrowed from non-headache indications, so management of cluster headache is challenging. However, as our understanding of cluster headache pathophysiology has evolved on the basis of key bench and neuroimaging studies, crucial neuropeptides and brain structures have been identified as emerging treatment targets. In this Review, we provide an overview of what is known about the pathophysiology of cluster headache and discuss the existing treatment options and their mechanisms of action. Existing acute treatments include triptans and high-flow oxygen, interim treatment options include corticosteroids in oral form or for greater occipital nerve block, and preventive treatments include verapamil, lithium, melatonin and topiramate. We also consider emerging treatment options, including calcitonin gene-related peptide antibodies, non-invasive vagus nerve stimulation, sphenopalatine ganglion stimulation and somatostatin receptor agonists, discuss how evidence from trials of these emerging treatments provides insights into the pathophysiology of cluster headache and highlight areas for future research.

Comprehensive clinical phenotyping of nitroglycerin infusion induced cluster headache attacks

Background

Nitroglycerin administration allows the study of cluster headache attacks in their entirety in a standardised way.

Methods

A single-blind, placebo-controlled, cross-over study using weight-calculated intravenous nitroglycerin administration at 0.5 µg/kg/min over 20 minutes to study cluster headache attacks, including accompanying non-headache symptoms and cranial autonomic symptoms.

Results

Thirty-three subjects with cluster headache were included in the study; 24 completed all three study visits. Nitroglycerin-induced attacks developed in 26 out of 33 subjects (79%) receiving unblinded nitroglycerin infusion, and in 19 out of 25 subjects (76%) receiving single-blinded nitroglycerin infusion, compared with one out of 24 subjects (4%) receiving single-blinded placebo infusion. Episodic cluster headache subjects had a shorter latency period to a nitroglycerin-induced attack compared to the chronic cluster headache (CCH) subjects (U = 15, z = −2.399, p = 0.016). Sixteen of nineteen episodic cluster headache (mean, 84%; 95% confidence interval, 66–100%) and 11 of 14 chronic cluster headache subjects developed a nitroglycerin-induced attack (79%, 54–100%) following the unblinded nitroglycerin infusion. Following the single-blinded nitroglycerin infusion, eight out of 13 episodic cluster headache (62%, 31–92%) and 11 out of 12 chronic cluster headache (92%, 73–100%) subjects developed nitroglycerin-induced attacks. Nitroglycerin induced non-headache symptoms in the majority of subjects receiving it: 91% in the open unblinded nitroglycerin visit and 84% in the single-blinded nitroglycerin visits, compared with 33% in the single-blinded placebo visit. Cranial autonomic symptoms were induced by nitroglycerin infusion, 94% in the open unblinded nitroglycerin visit and 84% in the single-blinded nitroglycerin visit, compared with 17% in the single-blinded placebo visit.

Conclusion

Intravenous weight-adjusted nitroglycerin administration in both episodic cluster headache in bout and chronic cluster headache is effective and reliable in inducing cluster headache attacks, cranial autonomic symptoms and non-headache symptoms.

Current Understanding of the Chronobiology of Cluster Headache and the Role of Sleep in Its Management

Cluster headache is uniquely rhythmic in its occurrence both diurnally and annually. This has implications for the clinical approach to the patient but also for our understanding of the role of central structures in its pathological basis. Many intrinsic and extrinsic factors seem to influence CH rhythmicity, including genetics. The proclivity for attacks to occur at night and the possible association with particular sleep phenomena, including sleep apnea, have motivated a number of studies which has improved our understanding but many questions remain unanswered. The sleep-headache interaction seems to be bidirectional and possibly both direct and indirect. The latter could involve more disperse networks of homeostatic regulation, which may better encompass recent observations. Treatment of the headache patient with concurrent sleep problems can be particularly challenging, especially considering side-effects and interactions of commonly used medications. While current treatment guidelines do not incorporate chronotherapeutic thinking, some evidence may suggest that application of such principles on an individual level may be beneficial.

Recently available and emerging therapeutic strategies for the acute and prophylactic management of cluster headache: a systematic review and expert opinion

Introduction: Although it causes a huge burden to sufferers, cluster headache (CH), remains an undertreated condition, partly due to the absence of established acute and prophylactic treatment options. New therapeutic approaches providing fast and safe relief from CH are needed. Areas covered: A systematic review was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendation on recently published (last 5 years) papers on CH treatment. The authors also collected preliminary results from ongoing trials on emerging therapeutic/preventive pharmacological and interventional approaches for CH. Studies and results are reviewed and discussed. Expert opinion: The complexity of CH pathophysiology prevents the definition of reliable acute and preventive treatments. In the real-world clinical setting, several treatments are combined to provide relief to patients and increase their quality of life. Drugs targeting neuropeptides or their receptors within the trigeminovascular network are of particular interest to prevent CH attacks. Calcitonin gene-related peptide (CGRP) blockade seems attractive and promising, but studies on anti-CGRP monoclonal antibodies indicated rather modest or even absence of a prophylactic effect. A deeper insight into CH pathophysiology, and combined approaches may lead the path to new, more effective, and personalized CH therapies.

Drug profile: galcanezumab for prevention of cluster headache

Introduction: Cluster headache [CH] is a severely disabling trigeminal autonomic cephalalgia [TAC]. Approximately 1 in 1,000 adults are affected by CH. Calcitonin gene-related peptide [CGRP] is an important mediator in the pathophysiology of CH. Galcanezumab is a monoclonal antibody with an affinity for the CGRP peptide, FDA approved for the prevention of episodic CH. Areas covered: Search words queried were 'cluster headache,' 'cluster headache, and CGRP,' 'cluster headache, and galcanezumab.' Over 99 articles in Pubmed and prescribing information for galcanezumab were reviewed. Some of the data pertaining to CH trials with fremanezumab were reviewed using clinical trials.org. Expert opinion: Galcanezumab has shown benefit in decreasing the weekly frequency of CH attacks across week 1 through week 3 in patients with CH; 8.7 attacks in the galcanezumab group, as compared with 5.2 in the placebo group (95% confidence interval, 0.2 to 6.7; P = 0.04). It has a favorable risk-benefit ratio. The prevention of CH with CGRP inhibition represents a novel advance for a condition with a significant unmet need. The negative trial results of galcanezumab for chronic cluster headache [CCH] may be due to the refractory nature and sheds light on the critical need to investigate the underlying biology and therapeutic options.

Erenumab-Induced Severe Nausea Leading to Smoking Cessation: A Retrospective Case Series

OBJECTIVE

Erenumab is a novel treatment modality with a relatively benign and safe side effect profile, currently approved for the prevention of migraine headache. We present 3 cases with chronic migraine who are cigarette smokers were prescribed erenumab, and developed an intense smoking-induced nausea which eventually led to smoking cessation.

METHODS

A multicenter retrospective review of 3 cases with cigarette smoking, one of whom was also smoking marijuana, suffering from chronic migraine resistant to multiple preventive therapies was studied. All were prescribed monthly injections of erenumab 70 mg. Response in terms of headache frequency and intensity and smoking habits was obtained through medical record review.

RESULTS

Out of 3 patients, 2 reported reduced headache frequency and intensity. All patients developed severe nausea while smoking cigarettes after their first dose of erenumab, leading to smoking cessation. One patient co-smoked marijuana, which did not result in nausea after being treated.

CONCLUSION

To the best of our knowledge, this is the first report of severe nausea secondary to erenumab administration and smoking cigarettes, which finally resulted in complete cigarette smoking cessation. As such, further study is indicated on the benefit of erenumab and other calcitonin gene-related peptide antagonists in migraineurs who smoke to promote smoking cessation.

Understanding and Minimising Injection-Site Pain Following Subcutaneous Administration of Biologics: A Narrative Review

Injection-site pain (ISP) is a subjective side effect that is commonly reported with the subcutaneous administration of biological agents, yet it may only be a concern to some. Multiple factors related to the product formulation, such as pH, volume and excipients, and/or to the injection process have the potential to contribute to ISP, while patient-related factors, such as low body weight, gender and age, can make an individual more susceptible to experiencing ISP. While total elimination of ISP remains unlikely with any subcutaneously administered agent, it can be minimised by helping the patient to develop a confident and competent injection technique via robust and effective training. Careful management of patient expectations along with open discussion regarding the potential risk of ISP may serve to minimise treatment-related anxieties and, importantly, allow the patient to remain in control of his/her treatment. Other interventions to help minimise ISP include psychological interventions, allowing biologics to reach room temperature prior to injection, using the most suitable injection device for the individual patient and selecting an alternative drug formulation, when available. Productive patient–physician communication remains important in order to support and optimise treatment experience and adherence, while also providing the opportunity for patients to discuss any ISP-related issues.

Real-life treatment of cluster headache in a tertiary headache center - results from the Danish Cluster Headache Survey

BACKGROUND

Pharmacological treatment of cluster headache constitutes the core of clinical management, but evidence is sparse. We aimed to generate insight in the existing treatment and identify associations between clinical features and treatment response.

METHODS

Patients aged 18-65 diagnosed with cluster headache according to the ICHD-2 completed a questionnaire followed by a structured interview. Multiple logistic regression was used to identify associations.

RESULTS

The population consisted of 400 patients with an episodic: chronic ratio of 1.7:1. Episodic patients were more likely to respond to triptans (odds ratio = 1.77, confidence interval: 1.08-2.91, p = 0.023) and oxygen (odds ratio = 1.64, confidence interval: 1.05-2.57, p = 0.031) than chronic. Oxygen response was less likely if pain intensity was very severe (odds ratio = 0.53, confidence interval: 0.33-2.57, p = 0.006) and the risk of a poor response increased with disease duration (odds ratio = 0.79, confidence interval: 0.65-0.96, p = 0.016). Among current users of sumatriptan injection and oxygen, the proportion achieving 100% relief was higher with sumatriptan injection (p > 0.001) than with oxygen. No associations were identified regarding verapamil. Only 57% of current users of preventive medication responded at a 50% level.

CONCLUSION

Episodic cluster headache is more responsive to acute therapy than chronic. Further, sumatriptan injection was more effective than oxygen and the responder-rate was limited with verapamil. More effective acute and preventive therapies are needed for cluster headache patients.

[Cluster headaches-proven and novel approaches : A critical evaluation of treatment studies]

Trigeminal autonomic cephalalgias are characterized by unilateral headaches accompanied by cranial autonomic symptoms and a sense of restlessness. Clinical trials have been conducted on acute therapy and prophylaxis of cluster headache in recent years. Since the other trigeminal autonomic cephalalgias are rare, it is virtually impossible to conduct controlled clinical trials for their investigation. Recent trials provide data on the efficacy of prednisolone, galcanezumab, fremanzeumab and noninvasive vagal nerve stimulation. Methodological difficulties arise in terms of patient recruitment for clinical trials, clinical endpoints and potential differences in the pathophysiology of episodic and chronic cluster headache.

Erenumab for chronic cluster headache: A case report

The preventive treatment for cluster headache is often limited by a lack of efficacy or side effects. Calcitonin gene-related peptide (CGRP) has been implicated in the pathophysiology of cluster headache. Galcanezumab, a monoclonal antibody against calcitonin gene-related peptide (CGRP), significantly reduced the frequency of episodic cluster headache attacks. We report the case of a 38-year-old woman with chronic refractory cluster headache and comorbid migraine who received erenumab in 4 repeated doses of 70 mg subcutaneously over 25 weeks. Attack frequency decreased from three attacks per day to several attacks per week. Erenumab seemed to be highly effective in the prevention of cluster headache attacks in this patient. We suggest that randomized control trials should be performed.

Cluster headache not responsive to sumatriptan: A retrospective study

INTRODUCTION

Subcutaneous sumatriptan, a 5HT_1B/1D agonist, is the most effective drug in cluster headache acute treatment. About 25% of the patients do not respond to subcutaneous sumatriptan; the reasons for this are unknown. In this study, we compare clinical characteristics of cluster headache patients responding and non-responding to subcutaneous sumatriptan.

METHODS

We retrospectively investigated the clinical records of 277 cluster headache patients. Patients reporting repeated satisfactory response to subcutaneous sumatriptan within 15 minutes were considered responders.

RESULTS

Of 206 cluster headache patients who had used subcutaneous sumatriptan (mean age 45.6, 16% females, 48% chronic), 91% were responders, and 9% non-responders. Compared to responders, non-responders had longer and more frequent attacks: 60 (median; IQR 38-90) vs. 100 (60-120) minutes (p = 0.028), 4 (2.5-5) vs. 3 (2-4) attacks/day (p = 0.024). No other difference was found.

CONCLUSIONS

In cluster headache attacks with long duration and high frequency, pain mechanisms not involving 5HT_1B/1D receptors may play a more relevant role.

Refractory short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing responsive to anti-calcitonin gene-related peptide monoclonal antibodies: A case report

BACKGROUND

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) is a rare but severely disabling variant within the spectrum of trigeminal autonomic cephalalgia lacking evidence-based treatment.

CASE

We report a case of chronic SUNCT in a 67-year-old man refractory to various guideline-conforming treatment attempts responding excellently to galcanezumab.

CONCLUSIONS

This case report indicates that monoclonal antibodies against calcitonin gene-related peptide, specifically galcanezumab, might be a treatment option for SUNCT warranting further investigation.

Baseline tear fluid CGRP is elevated in active cluster headache patients as long as they have not taken attack abortive medication

BACKGROUND

Calcitonin gene-related peptide plays a key role in cluster headache pathophysiology. It is released from the trigeminal nerve, which also innervates the eye. In this study, we tested if tear fluid calcitonin gene-related peptide measurement detects elevated calcitonin gene-related peptide levels in cluster headache patients compared to controls.

METHODS

Calcitonin gene-related peptide concentration in tear fluid and plasma of 16 active episodic and 11 chronic cluster headache patients (all outside acute attacks) and 60 controls were assessed using ELISA.

RESULTS

Cluster headache patients without use of attack abortive medication in the last 48 h showed significantly elevated tear fluid calcitonin gene-related peptide levels (1.78 ± 1.57 ng/ml, n = 17) compared to healthy controls (0.79 ± 0.74 ng/ml, p = 0.003) and compared to cluster headache patients who had used attack abortive medication in the last 48 h (0.84 ± 1.40 ng/ml, n = 10, p = 0.022). High calcitonin gene-related peptide levels in cluster headache patients were independent of the occurrence of a cluster headache attack in the last 48 hours (no attack: 1.95 ± 1.65 ng/ml, n = 8; attack: 1.63 ± 1.59 ng/ml, n = 9, p = 0.82) as long as no acute medication was used. No significant difference in tear fluid calcitonin gene-related peptide levels between episodic (1.48 ± 1.34 ng/ml) and chronic cluster headache patients (2.21 ± 1.88 ng/ml, p = 0.364) was detected. In contrast to these results in tear fluid, there were no significant group differences in plasma calcitonin gene-related peptide levels.

CONCLUSION

This study shows that active cluster headache patients have increased calcitonin gene-related peptide levels in tear fluid compared to healthy subjects, which are reduced to control levels after intake of attack abortive medication. Calcitonin gene-related peptide measurement in tear fluid is non-invasive, and has the advantage of allowing direct access to calcitonin gene-related peptide released from the trigeminal nerve.

Effect of calcitonin gene-related peptide (-receptor) antibodies in chronic cluster headache: Results from a retrospective case series support individual treatment attempts

Objective

To assess the efficacy of monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor in chronic cluster headache (CCH) treatment under real world conditions.

Background

Calcitonin gene-related peptide has an important pathophysiological role in cluster headache. Although the randomised controlled trial with the calcitonin gene-related peptide antibody galcanezumab was negative, chronic cluster headache patients with insufficient response to other preventive treatments have been receiving individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies.

Methods

Data from 22 chronic cluster headache patients who received at least one dose of a calcitonin gene-related peptide(-receptor) antibody and recorded attack frequency in a headache diary were retrospectively collected at eight headache centres.

Results

The number of previous preventive therapies was 6.5 ± 2.4 (mean ± standard deviation, range: 2–11). The average number of attacks per week was 23.3 ± 16.4 at baseline and significantly decreased by −9.2 ± 9.7 in the first month of treatment with a calcitonin gene-related peptide(-receptor) antibody (p < 0.001). Fifty-five percent of the patients were 50% responders and 36% were 75% responders with respect to attack frequency. Significant reduction of attack frequency started at week 1 (−6.8 ± 2.8 attacks, p < 0.01). Results were corroborated by significant decreases in weekly uses of acute headache medication (−9.8 ± 7.6, p < 0.001) and pain intensity during attacks (−1.2 ± 2.0, numerical rating scale (NRS) [0–10], p < 0.01) in the first month. In months 2 (n = 14) and 3 (n = 10), reduction of attack frequency from baseline was −8.0 ± 8.4 (p = 0.004) and −9.1 ± 10.0 (p = 0.024), respectively.

Conclusion

Under real-world conditions, individual treatment with calcitonin gene-related peptide(-receptor) antibodies was effective in 55% of our chronic cluster headache patients. This finding supports individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies in chronic cluster headache patients insufficiently responding to other therapies.

Reducing Episodic Cluster Headaches: Focus on Galcanezumab

The involvement of calcitonin gene-related peptide in migraine and cluster headache has led to the recent development of new therapies. Galcanezumab, a novel monoclonal antibody targeting the calcitonin gene-related peptide, is approved for the migraine prevention and has recently been tested for the prevention of cluster headache. Two clinical trials have been conducted to investigate the efficacy and safety of galcanezumab in episodic cluster headache and chronic cluster headache. While efficacy endpoints were not met in the chronic subtype, galcanezumab reduced the weekly frequency of attacks in patients with episodic cluster headaches. In both studies, the antibody was well tolerated. This review summarizes and critically reviews the available data regarding the rationale behind targeting the calcitonin gene-related peptide with galcanezumab for the prevention of cluster headache.

Galcanezumab for the prevention of cluster headache

INTRODUCTION

Cluster headache (CH) is among the worst painful conditions. The available therapies are scarce and not specific, leaving many patients unsatisfied because of poor efficacy and/or tolerability. Patients not responding to common treatments are offered semi-invasive and invasive procedures with uncertain results. Based on the current understanding of CH pathophysiology, new possible therapeutic approaches come from drugs interfering with Calcitonin Gene Related Peptide (CGRP).

AREAS COVERED

After summarizing the evidence for CGRP involvement in CH pathophysiology, we review the published literature (PubMed) and information (clinicaltrials.gov, EudraCT, EMA and FDA websites) regarding a novel anti-CGRP monoclonal antibody, Galcanezumab, its pharmacological properties, development, and evidence for the treatment of CH. Publications regarding other indications (migraine) are considered for completeness and safety/tolerability profile.

EXPERT OPINION

In one randomized clinical trial, Galcanezumab has proven to be effective and safe as a preventive treatment in episodic CH, with a favorable tolerability profile offering a potential new option in the therapeutic arsenal. Inefficacy of galcanezumab in chronic CH as well as the inefficacy of another monoclonal antibody against CGRP (fremanezumab) in both episodic and chronic CH question the scalability of the drug in CH management. Further, studies comparing galcanezumab to the current standard treatments are highly desirable.

Cluster headache in Asian populations: Similarities, disparities, and a narrative review of the mechanisms of the chronic subtype

OBJECTIVE

Headache disorders like migraine show geographic and ethnic differences between Asian and European/North American countries. In cluster headache, these differences are rarely mentioned and discussed. This article aimed to review the characteristics of cluster headache in Asian countries and compare the clinical features to those in European and North American populations.

METHODS

We conducted a narrative literature review on the demographics, clinical presentations, and treatments of cluster headache in Asian countries.

RESULTS

Patients with cluster headache in Asian populations showed a stronger male predominance compared to European and North American populations. Chronic cluster headache was rare in Asian countries. The clinical presentation of restlessness was not as common in Asian as it was in European and North American countries, and Asian patients with aura were extremely rare. Patients in Asian countries may have a lower circadian rhythmicity of cluster headache and a lower headache load, as demonstrated by lower attack frequencies per day, bout frequencies, and bout durations.

CONCLUSIONS

Regional differences in the presentation of cluster headache exist. Greater awareness for cluster headache should be raised in Asian regions, and further studies are warranted to elucidate the mechanisms behind observed differences.