Erenumab for episodic migraine prophylaxis

An update on pharmacotherapy for trigeminal neuralgia

INTRODUCTION

Trigeminal neuralgia is a rare condition that can be effectively treated by carbamazepine or oxcarbazepine but these older drugs are associated with dose-dependent and potentially treatment-limiting adverse effects. Third-generation anticonvulsants, new calcitonin gene-related peptide blockers for migraine, and older drugs such as ketamine and cannabinoids may be promising adjuvants or monotherapeutic options.

AREAS COVERED

The new drugs, their presumed mechanisms of action, safety and efficacy are discussed herein. There is a paucity of robust clinical evidence in support of these drugs for trigeminal neuralgia. New migraine agents are considered as well although migraines and trigeminal neuralgia are distinct, albeit similar, conditions. No new drugs have been released to market in recent years with the specific indication of trigeminal neuralgia.

EXPERT OPINION

In real-world clinical practice, about half of trigeminal neuralgia patients take more than one agent for prevention and combination therapy may be the optimal approach. Combination therapy might allow for lower doses of carbamazepine or oxcarbazepine, thus reducing the number and severity of potential adverse events but the potential for pharmacokinetic drug-drug interactions must be considered. Drug therapy for trigeminal neuralgia involves acute or abortive treatments, often administered in hospital versus long-term preventive therapy, usually involving oral agents.

Monoclonal Antibodies for Chronic Pain Treatment: Present and Future

Chronic pain remains a major problem worldwide, despite the availability of various non-pharmacological and pharmacological treatment options. Therefore, new analgesics with novel mechanisms of action are needed. Monoclonal antibodies (mAbs) are directed against specific, targeted molecules involved in pain signaling and processing pathways that look to be very effective and promising as a novel therapy in pain management. Thus, there are mAbs against tumor necrosis factor (TNF), nerve growth factor (NGF), calcitonin gene-related peptide (CGRP), or interleukin-6 (IL-6), among others, which are already recommended in the treatment of chronic pain conditions such as osteoarthritis, chronic lower back pain, migraine, or rheumatoid arthritis that are under preclinical research. This narrative review summarizes the preclinical and clinical evidence supporting the use of these agents in the treatment of chronic pain.

The locus of Action of CGRPergic Monoclonal Antibodies Against Migraine: Peripheral Over Central Mechanisms

Migraine is a complex neurovascular disorder characterized by attacks of moderate to severe unilateral headache, accompanied by photophobia among other neurological signs. Although an arsenal of antimigraine agents is currently available in the market, not all patients respond to them. As Calcitonin Gene-Related Peptide (CGRP) plays a key role in the pathophysiology of migraine, CGRP receptor antagonists (gepants) have been developed. Unfortunately, further pharmaceutical development (for olcegepant and telcagepant) was interrupted due to pharmacokinetic issues observed during the Randomized Clinical Trials (RCT). On this basis, the use of monoclonal antibodies (mAbs; immunoglobulins) against CGRP or its receptor has recently emerged as a novel pharmacotherapy to treat migraines. RCT showed that these mAbs are effective against migraines producing fewer adverse events. Presently, the U.S. Food and Drug Administration approved four mAbs, namely: (i) erenumab; (ii) fremanezumab; (iii) galcanezumab; and (iv) eptinezumab. In general, specific antimigraine compounds exert their action in the trigeminovascular system, but the locus of action (peripheral vs. central) of the mAbs remains elusive. Since these mAbs have a molecular weight of ∼150 kDa, some studies rule out the relevance of their central actions as they seem unlikely to cross the Blood-Brain Barrier (BBB). Considering the therapeutic relevance of this new class of antimigraine compounds, the present review has attempted to summarize and discuss the current evidence on the probable sites of action of these mAbs.

Effect of fremanezumab on quality of life and productivity in patients with chronic migraine

OBJECTIVE

To evaluate fremanezumab quarterly or monthly vs placebo on health-related quality of life, health status, patients' global impression of change, and productivity in patients with chronic migraine (CM).

METHODS

HALO CM was a double-blind, placebo-controlled trial in patients with CM. Patients were randomized 1:1:1 to treatment with fremanezumab quarterly (675 mg at baseline, placebo at weeks 4 and 8), fremanezumab monthly (225 mg at baseline, weeks 4 and 8), or placebo. This article assessed the effect of treatment with fremanezumab on health-related quality of life and productivity using the following prespecified assessments: the Migraine-Specific Quality of Life (MSQoL) questionnaire at baseline and weeks 4, 8, and 12; Patient Global Impression of Change (PGIC) questionnaire at weeks 4, 8, and 12; and EuroQoL 5-dimension, 5-response level (EQ-5D-5L) questionnaire and Work Productivity and Activity Impairment: General Health (WPAI:GH) questionnaire at baseline and week 12.

RESULTS

The full analysis set included 1,121 patients: 375 patients with quarterly dosing, 375 with monthly dosing, and 371 with placebo. Fremanezumab quarterly and monthly was associated with significant improvements over placebo in change from baseline mean scores in MSQoL domains (all, p < 0.05) to week 12. At week 12, fremanezumab also showed significant improvements in EQ-5D-5L visual analog scale (p < 0.05) and PGIC scores (p < 0.0001) as well as significant reductions from baseline in WPAI:GH scores (p < 0.01) and presenteeism (impairment while working; p < 0.05) vs placebo.

CONCLUSIONS

Fremanezumab quarterly or monthly was associated with improvement over placebo in migraine-specific quality of life, overall health status, patients' global impression of change with treatment, and productivity in patients with CM.

CLINICALTRIALSGOV IDENTIFIER

NCT02621931.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in patients with CM, treatment with fremanezumab quarterly or monthly is associated with improvements in health-related quality of life and productivity.