Why carry out this study?

Migraine carries a high disease burden, and, although analgesic use for acute treatment of migraine is common, not all patients who might benefit from preventive therapy receive it.

Number needed to treat (NNT) and number needed to harm (NNH) are metrics of effect size that can be used to evaluate benefit–risk profiles and may help guide clinical decision-making.

This study evaluated the benefit–risk profile of galcanezumab using number needed to treat (NNT), number needed to harm (NNH), and likelihood to be helped or harmed (LHH), as calculated from the phase 3 clinical trial program.

What was learned from the study?

Across 4 trials, galcanezumab treatment demonstrated robust NNTs versus placebo to achieve response and favorable NNHs versus placebo associated with discontinuations due to adverse events; in combination, these findings suggest galcanezumab is an effective preventive treatment for both chronic and episodic migraine with an excellent safety profile, where the benefits outweigh the possible risks associated with the drug.

More robust NNTs for galcanezumab versus placebo were observed for patients with episodic migraine (EM) than with chronic migraine (CM) overall; however, in patients with failure of ≥ 2 prior preventive treatments, the NNTs versus placebo to achieve ≥ 30% and ≥ 50% response were similar between patients with EM and those with CM.