Calcitonin gene-related peptide antagonists versus botulinum toxin A for the preventive treatment of chronic migraine protocol of a systematic review and network meta-analysis: A protocol for systematic review

OnabotulinumtoxinA for the prophylactic treatment of headaches in adult patients with chronic migraine: a safety evaluation

Introduction: Existing oral prophylaxis for chronic migraine (CM) are often ineffective or poorly tolerated. OnabotulinumtoxinA (onabotA) is approved for headache prophylaxis in CM and ameliorates headaches in patients refractory to multiple preventatives.Areas covered: We appraise evidence regarding action mechanisms, pharmacodynamics, and pharmacokinetics of onabotA in CM prophylaxis. We critically evaluate salient clinical and real-world studies demonstrating its efficacy in improving multiple aspects of CM. We discuss onabotA safety, tolerability, and adverse events (AEs) for CM prophylaxis from clinical trials, post-authorization studies and meta-analyses, including novel pregnancy safety data and comparisons with oral prophylactics. We explore areas of future interest, particularly onabotA safety and efficacy in the context of novel antibody-based prophylaxis.Expert opinion: Clinical and real-world evidence demonstrate onabotA safety, tolerability and efficacy for CM prophylaxis. Most AEs are mild/moderate and self-limiting, with few serious AEs and no treatment-related deaths. Common AEs include neck pain, ptosis, muscle weakness, and stiffness. Modifying existing responder-criteria enables more patients to benefit from onabotA. OnabotA shows superior safety and efficacy to oral preventatives, and appears safe in pregnancy. Future pregnancy-risk register will clarify pregnancy and lactation safety further. Future research comparing onabotA safety and efficacy with newly emergent antibody-based prophylaxis is keenly awaited.

OnabotulinumtoxinA in Migraine: A Review of the Literature and Factors Associated with Efficacy

The efficacy of onabotulinumtoxinA (OnaB-A) as a preventative treatment for chronic migraine, emerging fortuitously from clinical observation is now supported by class one evidence and over two decades of real-world clinical data. There is still limited ability to predict a clinically meaningful response to OnaB-A for individual patients, however. This review summarises briefly the proposed mechanism of OnaB-A in chronic migraine, the literature of predictors of clinical response, and recent developments in the field.

Calcitonin Gene-Related Peptide Monoclonal Antibodies Versus Botulinum Neurotoxin a in the Preventive Treatment of Chronic Migraine: An Adjusted Indirect Treatment Comparison Meta-Analysis

Purpose: Calcitonin gene-related peptide monoclonal antibodies (CGRPmAbs) are new agents approved by the US Food and Drug Administration for preventive treatment of chronic migraine. Comparison between CGRPmAbs and previously approved Botulinum neurotoxin A (BoNT-A) will inform optimal preventive treatment of chronic migraine, but head-to-head trials are lacking. We therefore aimed to perform adjusted indirect comparison between CGRPmAbs and BoNT-A through a meta-analysis.

Methods: OVID MEDLINE, EMBASE and the Cochrane central register of controlled trials, clinical registries, and government websites were searched from inception to September 2019. Randomized controlled trials comparing CGRPmAbs or BoNT-A with placebo in the preventive treatment of chronic migraine were included. The primary outcomes were headache days and migraine days measured at week 12. Data were synthesized by using a frequentist approach; and the treatments were ranked by P-score.

Results: We included 10 trials (n = 4,678) after screening 1049 candidates. Six trials were with low risk of bias. Fremanezumab had an effect similar to BoNT-A in the reduction of headache days at week 12 (standard mean difference [SMD] 0.08, 95%CI -0.55 to -0.7). Galcanezumab reduced more migraine days than BoNT-A at week 12 (SMD, -0.94, 95%CI −1.24 to −0.63); fremanezumab showed similar findings (SMD, −0.55, 95%CI −0.85 to −0.24). Galcanezumab and fremanezumab had better effect in mitigating headache impact at week 12. CGRPmAbs and BoNT-A had similar adverse event rate.

Conclusion: CGRPmAbs and BoNT-A had similar effect in the preventive treatment of chronic migraine. BoNT-A might be preferentially selected owing to its cost-effectiveness profiles. Further studies with direct comparison of the two treatments are warranted.

OnabotulinumtoxinA in Chronic Migraine: A Profile of Its Use

OnabotulinumtoxinA (Botox^®; a formulation of botulinum toxin type A (BoNT/A)] is indicated for the prevention of headaches in adults with chronic migraine (CM) in numerous countries, including those of Europe. In clinical trials, intramuscular administration of BoNT/A (155-195 units at 12-week intervals) to patients with CM was generally well tolerated and associated with sustained and clinically meaningful improvements in multiple assessments of headache symptoms, headache-related impact and/or disability and migraine-specific health-related quality of life over a period of 1 year (in the pivotal PREEMPT 1 and 2 studies) and 2 years (in the phase IV COMPEL study). The efficacy and safety of BoNT/A therapy have been confirmed in a number of large, prospective, real-world studies conducted in Europe, including the 2-year REPOSE study. Intramuscular BoNT/A has also demonstrated greater clinical utility than the oral prophylactic medication topiramate in a clinical practice setting (FORWARD study).