Eli Lilly and Co. said its treatment galcanezumab met the main goal of a late-stage trial in patients experiencing episodes of severe headaches.

The two-month study showed that the drug was better at reducing weekly cluster headache attacks when compared to placebo. However, the drug failed to meet its primary endpoint in patients who were experiencing a chronic form of the disease.

About 85% to 90% of all cluster headaches are categorized as episodic, while the chronic form of the disease is observed in about 10% to 15% of cases.

The U.S. Food and Drug Administration is reviewing galcanezumab as a nonopioid therapy for preventing migraines in adults, with a decision expected in the third quarter of 2018.

In May 2017, the drug met its main goals in three phase 3 studies for preventing chronic and episodic migraines. The drug was also found to be superior to placebo in preventing migraine headaches in patients who had failed at least two prior therapies.

Lilly's galcanezumab is in a race with rivals developing a similar class of migraine drugs, such as Teva Pharmaceutical Industries Ltd.'s fremanezumab and Amgen Inc. and Novartis AG's Aimovig.