KaloBios Pharmaceuticals, a biopharmaceutical company based in San Francisco, Calif., has initiated dosing in a randomized, double-blind, placebo-controlled phase II clinical trial of KB001-A, the company's anti-PcrV Humaneered, PEGylated monoclonal antibody fragment. The study will investigate the safety and efficacy of intravenously administered KB001-A as a treatment for chronic Pseudomonas aeruginosa (Pa) infection in cystic fibrosis patients.

The phase II study is being conducted at multiple centers in the U.S. and is designed to enroll 180 patients who will receive repeated doses of KB001-A over a 16-week period. The primary endpoint of the study will be time to need for antibiotics to treat worsening of respiratory tract signs and symptoms. Secondary endpoints will include changes in inflammatory markers, respiratory symptoms, subject-reported outcomes, measurements of lung function, pharmacokinetics, safety, and tolerability. This study is designed to expand upon the positive phase I/II results in cystic fibrosis patients with the precursor compound KB001. KaloBios expects to complete the study of KB001-A and announce results by mid-2014.

"Cystic fibrosis patients are subject to chronic lung infections with Pa, a gram negative bacteria which is a leading contributor to the deterioration of pulmonary function leading to respiratory failure," said Nestor A. Molfino, M.D., CMO at KaloBios. "The only currently approved treatments for Pa infections are antibiotics, but despite their therapeutic benefit, mortality and morbidity remain high due to Pa antibiotic resistance. KB001-A is designed to neutralize Pa pathogenicity which reduces inflammation and allows the body's natural immune system to kill and clear the bacteria. As a result, we believe KB001-A may offer a novel approach to preventing and treating Pa infections when added to antibiotics, and may not be subject to the typical drug resistance mechanisms."

David Pritchard, CEO of KaloBios, said, "We plan to use data from this phase II study of intravenous KB001-A, if positive, to support pivotal trials of a subcutaneous formulation of KB001-A."