First data from a mid-stage trial assessing Amgen’s fully human monoclonal antibody AMG 334 show the drug to be effective in preventing migraine, one of the world’s top 10 most debilitating conditions affecting more than 10% of the population. 

The global, double-blind, Phase II study met its primary endpoint by showing that AMG 334 significantly reduced monthly mean migraine days compared with placebo.

In the trial, 483 patients with a mean baseline of 8.7 migraine days per month were randomised to receive subcutaneous monthly placebo or AMG 334. Those taking the 70mg dose of the drug observed a statistically significant 3.4-day reduction in monthly migraine days compared with 2.28 days observed in control arm.  

AMG 334 also showed a significant increase in the 50% responder rate compared with placebo (47% versus 30%, respectively), while reductions in monthly headache days (-3.54 v. -2.39) and monthly migraine-specific medication use days (-1.64 vs -.69) were also recorded in the 70mg AMG 334 group, the firm noted.

Tolerability similar to placebo

On the safety side, tolerability was similar to placebo across all doses tested, the most commonly reported adverse events being fatigue, influenza, nasopharyngitis, arthralgia and back pain. No serious side effects were observed.

Amgen said it is “encouraged” by the data, which “further validate AMG 334 as a potential preventive treatment for episodic migraine”. The drug works by inhibiting the calcitonin gene-related peptide receptor believed to transmit signals that can cause incapacitating pain.