by Morris Levin, MD

This was an open label long-term study of a new parenteral drug delivery system for zolmitriptan – an “intracutaneous microneedle patch”. Results from a previously reported single treatment placebo-controlled study of this same product showed pain relief at 2 hours in 57% of the patients receiving placebo, and in 81% of those who used the active product.  Pain freedom at 2 hours was seen in 14% and 42% of subjects who received the placebo or active product respectively.  

In the study presented here, 335 subjects were allowed, in an open label format, to treat as many migraine attacks as they liked with the active product.  There were 5671 treated attacks.   44% resolved completely in 2 hours and 81% improved at that time point.  Interestingly, these responses were well-sustained over the next 24 and 48 hours.   Additionally, adverse effects were very infrequent, generally limited to injection site redness or swelling.   So, this new delivery system of a known effective acute migraine agent seems like very good news. 

Tempering the enthusiasm a bit is that fact that the placebo response rate in the blinded controlled study was very high at 57%, and presumably it was also high (or higher) in this open label study.  Still, in the “real world” as clinical medicine is often referred to, 81% pain relief is very compelling.

The authors of this study state in their conclusion, that efficacy rates in this open label long term study are similar to those in the previous controlled study.  While the numbers are similar, the comparison is actually not a fair one.   First, the lack of blinding and control here suggests that the predicted large placebo effect is in fact even more prominent than in the previous study, and therapeutic gain may therefore not be that significant.   Also, unlike the first study, patients with only mild pain were encouraged to use the treatment in this study.  This almost certainly increased response rates, although the number of headaches treated at mild levels was not large (7%).

Still, this product represents a very interesting new technology for triptan delivery, particularly since it is clear that parenteral triptan formulations are potentially significantly more effective than oral ones.   Hopefully this approach will continue to be studied and refined. 

 

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References:

• Ahmed Kassem A. Formulation approaches of triptans for management of migraine. Current drug delivery. 2016 Sep 1;13(6):882-98.