Shares of specialty pharmaceutical company Pharmos Corp. sunk Friday after the company said its pain medication candidate cannabinor failed a midstage study.

Shares of Pharmos fell 17 cents, or 9.3 percent, to $1.64 on the Nasdaq in midday trading. The stock has traded between $1.55 and $2.93 over the last 52 weeks.

The Phase IIa study involving 24 healthy male volunteers showed the drug was not effective in treating pain from a non-noxious stimulus to the skin, when compared to placebo. The study was randomized and double-blinded. Previous safety data was confirmed by the study and there were no serious adverse events.

"While we are disappointed that cannabinor did not show efficacy in this pain model, we have a newly developed oral formulation of cannabinor targeting chronic neuropathic pain with repeated administration," said Haim Aviv, chairman and chief executive.

The company will move on with a program to develop orally administered cannabinor and conduct a Phase I safety study. Also, a separate ongoing Phase IIa clinical trial for nociceptive pain is expected to be completed during the first quarter.