RESEARCH TRIANGLE PARK, S.C. (AP) — Icagen Inc. said Monday that its experimental asthma drug senicapoc failed the main goals of the biopharmaceutical company's midstage study, and it does not plan to keep developing the drug.

Icagen shares sank 44 percent in after-hours trading, falling 34 cents to 43 cents, after finishing regular trading down 6 cents, or 7.2 percent, at 77 cents.

Icagen said that in the study of 69 patients randomly receiving either 40 mg of senicapoc daily or a placebo, the drug didn't improve the patients' exercise-induced asthma symptoms.

The company plans to focus on its lead drug, which is being developed in epilepsy and pain trials, and on its early-stage pain treatments in partnership with Pfizer Inc.