Jain R, et al. - This study involved assessment of KB001-A, an anti-PcrV PEGylated monoclonal antibody fragment to the Type III secretion system of Pseudomonas aeruginosa (Pa). In cystic fibrosis (CF) patients infected with Pa, researchers assessed KB001-A associated impact on time-to-need for antibiotics for worsening respiratory signs and symptoms, as well as safety, and treatment-associated changes in symptom scores, inflammatory markers, and spirometry. Treatment with KB001-A was well-tolerated, safe and afforded a modest FEV₁ benefit and reduction in select sputum inflammatory markers (IL-8), with no reported association with an increased time to need for antibiotics. The lack of efficacy seen with KB001-A may be due, in part, to the low levels of the type III secretion proteins previously reported in sputum of CF patients chronically infected with Pa.