Non-vascular ATP-sensitive potassium channel activation does not trigger migraine attacks: A randomized clinical trial.

OBJECTIVE: To investigate the role of NN414, a selective KATP channel opener for the Kir6.2/SUR1 channel subtype found in neurons and ß-pancreatic cells, in inducing migraine attacks in individuals with migraine without aura. METHODS: Thirteen participants were randomly allocated to receive NN414 and placebo on two days separated by at least one week. The primary endpoint was the difference in the incidence of migraine attacks after NN414 compared with placebo. The secondary endpoints were the difference in the area under the curve for headache intensity scores, middle cerebral artery blood flow velocity (VMCA), superficial temporal artery diameter, heart rate and mean arterial pressure. RESULTS: Twelve participants completed the study, with two (16.6%) reporting migraine attacks after NN414 compared to one (8.3%) after placebo (p = 0.53). The area under the curve for headache intensity, VMCA, superficial temporal artery diameter, heart rate and mean arterial pressure did not differ between NN414 and placebo (p > 0.05, all comparisons). CONCLUSION: The lack of migraine induction upon activation of the Kir6.2/SUR1 channel subtype suggests it may not contribute to migraine pathogenesis. Our findings point to KATP channel blockers that target the Kir6.1/SUR2B subtype, found in cerebral vasculature, as potential candidates for innovative antimigraine treatments.Registration number: NCT04744129.

Second messenger signalling bypasses CGRP receptor blockade to provoke migraine attacks in humans.

There are several endogenous molecules that can trigger migraine attacks when administered to humans. Notably, calcitonin gene-related peptide (CGRP) has been identified as a key player in a signalling cascade involved in migraine attacks, acting through the second messenger cyclic adenosine monophosphate (cAMP) in various cells, including intracranial vascular smooth muscle cells. However, it remains unclear whether intracellular cAMP signalling requires CGRP receptor activation during a migraine attack in humans. To address this question, we conducted a randomized, double-blind, placebo-controlled, parallel trial using a human provocation model involving the administration of CGRP and cilostazol in individuals with migraine pretreated with erenumab or placebo. Our study revealed that migraine attacks can be provoked in patients by cAMP-mediated mechanisms using cilostazol, even when the CGRP receptor is blocked by erenumab. Furthermore, the dilation of cranial arteries induced by cilostazol was not influenced by the CGRP receptor blockade. These findings provide clinical evidence that cAMP-evoked migraine attacks do not require CGRP receptor activation. This discovery opens up new possibilities for the development of mechanism-based drugs for the treatment of migraine.

A systematic review, meta-analysis and meta-regression evaluating the adverse reactions to erenumab in the preventive treatment of migraine.

Background: Erenumab has recently been approved as a pharmacological treatment for the prevention of migraine. However, the incidence estimates of adverse drug reactions (ADRs) were not consistent among studies. Consequently, pooled measures of the incidences of ADRs that accounts for inter-study heterogeneity are desirable. In addition, little is known on the factors leading to such heterogeneity.Research design and methods: Clinical trials evaluating the occurrence of ADRs related to erenumab in migraine patients were searched with Ovid MEDLINE until April 2020. Random intercept models were used to estimate the pooled incidence of the ADRs reported at least in 5 different study populations. To examine whether specific factors correlated with the pooled incidence, we performed random-effects meta-regression.Results: Of 138 retrieved references, 8 clinical trials were included in the meta-analysis. We observed a significant heterogeneity of the incidence estimates of back pain, influenza, nasopharyngitis, and upper respiratory tract infection (URTI). Most of the observed heterogeneity is ascribed to treatment duration for back pain (p = 0.045), influenza (p < 0.001) and URTI (p < 0.001), and significantly attributed to Body Mass Index (BMI) for nasopharyngitis (p < 0.001).Conclusions: Back pain, influenza, nasopharyngitis and URTI showed a significant heterogeneity of incidence estimates.