Zynerba Pharmaceuticals Inc. said its epilepsy drug ZYN002 failed to meet its endpoints in a phase 2 trial.

The company was determining whether the cannabidiol gel could reduce the frequency of seizures in adult patients who were enrolled in the trial when compared to placebo.

Zynerba Pharmaceuticals shares were down nearly 59% to $6.19 as of 11:12 a.m. ET on Aug. 7.

The setback is not the end of the therapy though. The gel is also being investigated in patients with osteoarthritis and children with the Fragile X syndrome, with phase 2 clinical trial results expected in August and September, respectively.