Highlights from


International Neurotoxin Association (INA) annual meeting

Copenhagen 16-19 January 2019

Predictors of response

Dr. Pozo-Rosich tried to clarify whether there are clinical, molecular, or neurophysiologic predictors of response to botulinum neurotoxin in chronic migraine. In a prospective, multicentre study in which 79.3% of the patients treated with onabotulinum toxin A every 12 weeks for one year showed more than a 50% reduction in number of headaches per month, she observed that disease duration of less than 1 year increased the chances of treatment response. Unilaterality of pain, fewer days of disability per month, and milder headache at baseline correlated with a good outcome [1].

She recommended that the primary endpoint in controlled trials investigating preventive treatment in chronic migraine should either be defined as one or a combination of the following: change in migraine days, change in moderate-to-severe headache days, or responder rate. Dr Pozo-Rosich suggested that these three potential endpoints, if not selected as primary endpoints, should be considered as secondary endpoints. She said that efficacy can be assessed as improvements in headache frequency and intensity, in acute medication intake reduction, in better response to analgesics, in disability rates, and in frequency of associated symptoms/comorbidities such as depression. Pre-treatment evaluation, early response after 3 to 6 months, and long-term response after one year all have relevance as potential time points for assessing response to migraine prevention treatment. In addition, tolerability and adverse events should be evaluated and the non-responder rate determined.

What does a patient need?

Dr Pozo-Rosich continued that patients desperately want to stop the migraine cycle. They want to plan and programme their lives, be able to pack their luggage with more clothes than pills, and tolerate noises and lights. Other study participants mentioned that they wish to forget the anxiety they feel of not knowing when the next migraine will hit.

Thus, an efficient preventive measure for migraine first of all needs to be effective and tolerable, facilitate adherence, be persistence in effect, and should be designed for migraine, she said. Onabotulinum toxin A is a treatment specifically approved for the prophylaxis of chronic migraine in adults. When it comes to dosing, it became apparent over the years that 195 units are better than 155 units (no increase in secondary effects, improvement in disability).

  1. Pozo-Rosich P, et al. Poster 216, TOXINS 2019, Copenhagen, Denmark, 16-19 January, 2019.

The content and interpretation of these conference highlights are the views and comments of the speakers/authors.