Safety and Tolerability of Bacteriophage Therapy for Chronic Rhinosinusitis Due to Staphylococcus aureus

IMPORTANCE Staphylococcus aureus infections are associated with recalcitrant chronic rhinosinusitis (CRS). The emerging threat of multidrug-resistant S aureus infections has revived interest in bacteriophage (phage) therapy. OBJECTIVE To investigate the safety, tolerability, and preliminary efficacy of ascending multiple intranasal doses of investigational phage cocktail AB-SA01 in patients with recalcitrant CRS due to S aureus. DESIGN, SETTING, AND PARTICIPANTS This phase 1, first-in-humans, open-label clinical trial of multiple ascending doses was conducted at a single tertiary referral center from December 1, 2015, through September 30, 2016, with follow-up completed on December 31, 2016. Patients with recalcitrant CRS (aged 18-70 years) in whom surgical and medical treatment had failed and who had positive S aureus cultures sensitive to AB-SA01 were recruited. Findings were analyzed from February 2 through August 31, 2017. INTERVENTIONS Three patient cohorts (3 patients/cohort) received serial doses of twice-daily intranasal irrigations with AB-SA01 at a concentration of 3x10(8) plaque-forming units (PFU) for 7 days (cohort 1), 3x10(8) PFU for 14 days (cohort 2), and 3x10(9) PFU for 14 days (cohort 3). MAIN OUTCOMES AND MEASURES The primary study outcome was the safety and tolerability of intranasal AB-SA01. Safety observations included vital signs, physical examinations, clinical laboratory test results, and adverse events. The secondary outcome was preliminary efficacy assessed by comparing pretreatment and posttreatment microbiology results, disease-relevant endoscopic Lund-Kennedy Scores, and symptom scores using a visual analog scale and Sino-Nasal Outcome Test-22. RESULTS All 9 participants (4 men and 5 women; median age, 45 years [interquartile range, 41.0-71.5 years]) completed the trial. Intranasal phage treatment was well tolerated, with no serious adverse events or deaths reported in any of the 3 cohorts. No change in vital signs occurred before and 0.5 and 2.0 hours after administration of AB-SA01 and at the exit visit. No changes in biochemistry were found except for 1 participant in cohort 3 who showed a decrease in blood bicarbonate levels on exit visit, with normal results of physical examination and vital signs. All biochemistry values were normalized 8 days later. No changes in temperature were recorded before, during, or after treatment. Six adverse effects were reported in 6 participants; all were classified as mild treatment-emergent adverse effects and resolved by the end of the study. Preliminary efficacy results indicated favorable outcomes across all cohorts, with 2 of 9 patients showing clinical and microbiological evidence of eradication of infection. CONCLUSIONS AND RELEVANCE Intranasal irrigation with AB-SA01 of doses to 3x10(9) PFU for 14 days was safe and well tolerated, with promising preliminary efficacy observations. Phage therapy could be an alternative to antibiotics for patients with CRS.