Calcitonin gene-related peptide (CGRP) probably has a role in migraine pathophysiology,
and antagonism of its receptors might provide treatment without the vasoconstrictor
effects of triptans. We aimed to assess the clinical profile of MK-0974 (telcagepant),
an orally bioavailable antagonist of CGRP receptor.
In a randomised, parallel-treatment, placebo-controlled, double-blind, trial at 81
sites in the Europe and the USA, adults with migraine diagnosed by International Headache
Society criteria treated moderate or severe attacks with either oral telcagepant 150
mg or 300 mg, zolmitriptan 5 mg, or placebo. The five co-primary endpoints were pain
freedom, pain relief, or absence of photophobia, phonophobia, or nausea at 2 h after
treatment. Analysis was by the full analysis set and multiplicity was controlled for
with a step-down closed-testing procedure. This trial is registered with ClinicalTrials.gov,
1380 patients were randomly assigned to receive telcagepant 150 mg (n=333) or 300
mg (354), zolmitriptan (345), or placebo (348). Telcagepant 300 mg was more effective
than placebo for pain freedom (95 [27%] of 353 patients vs 33 [10%] of 343 [p<0.0001]),
pain relief (194 [55%] of 353 vs 95 [28%] of 343 [p<0.0001]), and absences of phonophobia
(204 [58%] of 353 vs 126 [37%] of 342 [p<0.0001]), photophobia (180 [51%] of 353 vs
99 [29%] of 342 [p<0.0001]), and nausea (229 [65%] of 352 vs 189 [55%] of 342 [p=0.0061]).
Efficacy of telcagepant 300 mg and zolmitriptan 5 mg were much the same, and both
were more effective than telcagepant 150 mg. Adverse events were recorded for 31%
taking telcagepant 150 mg, 37% taking telcagepant 300 mg, 51% taking zolmitriptan
5 mg, and 32% taking placebo.
Telcagepant 300 mg is effective as an acute treatment for migraine with efficacy comparable
to that of zolmitriptan 5 mg, but with fewer associated adverse effects.
Merck Research Laboratories.