KB001-A, an anti-PcrV monoclonal antibody (mAb) fragment for the treatment of cystic fibrosis (CF) patients with Pseudomonas aeruginosa (Pa), was awarded orphan drug designation by the FDA, according to manufacturer KaloBios Pharmaceuticals.

“The FDA’s designation of KB001-A as an orphan drug is another milestone for KaloBios as we continue the clinical development work required for potential FDA approval,” said David W. Pritchard, KaloBios’ president and chief executive officer. “We are working hard to complete enrollment of our Phase 2 trial and look forward to evaluating and reporting on the activity of KB001-A in late 2014.”

KaloBios is currently enrolling patients for a Phase 2 multiple-dose, randomized, double-blind, placebo-controlled clinical trial with KB001-A in CF patients chronically infected with Pa. This 180-patient study is intended to evaluate the efficacy and safety of repeat doses of KB001-A.