The U.S. Food and Drug Administration approved Eli Lilly and Co.'s Emgality as the first drug for treating episodic cluster headaches in adults.

Cluster headaches are recurrent attacks of severe headaches on one side of the head, frequently associated with pain behind or around one eye, restlessness and agitation. The attacks typically last 15 to 180 minutes and can occur many times a day during a cluster period.

Emgality, or galcanezumab, is an under-the-skin injection that can be self-administered once a month.

The FDA's approval for Emgality is based on a phase 3 study, which showed that the drug helped reduce weekly episodes of cluster headaches.

Emgality is already approved for preventing migraine in adults. The U.S. FDA granted a breakthrough-therapy designation to Emgality in September 2018 and a priority review status in March 2019.