Bacteriophage therapy, which uses lytic viruses as antimicrobials, has received renewed interest to address the emerging antimicrobial resistance (AMR) crisis. Cystic fibrosis (CF), a disease complicated by recurrent P. aeruginosa pulmonary infections that cause lung function decline, is an example where AMR is already a clinical problem. While bacteria evolve bacteriophage resistance, we developed a strategy to select bacteriophages that target bacterial cell surface receptors that contribute to antibiotic resistance or virulence. Thus, in addition to killing bacteria, these phages steer surviving, evolved bacteria to antibiotic re-sensitivity or attenuated virulence. Here, we present outcomes from nine CF adults treated with nebulized bacteriophage therapy for AMR P. aeruginosa using this personalized approach. Results showed that phage therapy: 1) reduced sputum P. aeruginosa, 2) showed evidence for predicted trade-offs in most subjects, and 3) improved lung function, which may reflect the combined effects of decreased bacterial sputum density and phage-driven evolved trade-offs.