KaloBios Pharma pulls plug on asthma drug, shares plunge

(Reuters) – Shares of KaloBios Pharmaceuticals Inc fell nearly 50 percent in extended trade after the company said it would stop developing an asthma drug that failed in a mid-stage study. The drug, KB003, failed to bring about a clinically meaningful improvement in the pulmonary function of patients with severe asthma when tested against a placebo in 160 patients. The San Francisco-based company said it would focus on developing other treatments in its pipeline, which include a drug for cancer and another to prevent a common gram negative bacterium. KaloBios shares fell to a low of $2.65 in extended trading.