Pfizer Begins Phase 2b Study Of Its Investigational Multi-antigen Staphylococcus aureus Vaccine In Adults Undergoing Elective Spinal Fusion Surgery

Pfizer Inc.

announced today enrollment of the first patient in a Phase 2b clinical trial of its investigational Staphylococcus aureus (S. aureus) multi-antigen vaccine (PF-06290510) in adults undergoing elective spinal fusion surgery. The purpose of the study, named STRIVE (STaphylococcus aureus SuRgical Inpatient Vaccine Efficacy), is to evaluate the safety and efficacy of the vaccine to determine if it prevents postoperative invasive S. aureus infections in patients undergoing elective spinal surgery.1 Surgical Site Infections (SSIs) are a significant and growing concern. SSIs caused by S. aureus account for approximately 20 percent of all SSIs in the U.S., and are associated with an estimated annual treatment cost of $12.3 billion in the U.S.2,3 Patients who suffer such infections due to antibiotic resistant (MRSA) or antibiotic sensitive (MSSA) S.aureus have worse clinical outcomes, including increased mortality in comparison with non-infected patients.4 "We are pleased to take this important next step in the development of our S. aureus vaccine," said Dr. Kathrin Jansen, senior vice president and chief scientific officer of Vaccine Research and Development for Pfizer. "To date, there is no licensed vaccine available to prevent invasive S. aureus disease. We believe results from this study, if positive, will bring us closer to a potential preventive measure for this challenging disease that is associated with considerable morbidity and mortality." The primary outcome of the study, with an estimated enrollment of 2600 subjects, will measure the number of subjects in each treatment group with postoperative S. aureus blood stream infections and/or deep incisional or organ/space surgical site infections occurring within 90 days after elective posterior instrumented lumbar spinal fusion. Secondary outcomes will also measure postoperative S. aureus blood stream infections and/or deep incisional or organ/space surgical site infections occurring within 180 days after surgery, and postoperative S. aureus surgical site infections occurring within 90 and 180 days after elective posterior instrumented lumbar spinal fusion. Estimated completion of the study is 2017. More information on the trial can be found at: https://clinicaltrials.gov/show/NCT02388165 Pfizer's S. aureus vaccine was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) in February 2014. The Fast Track process facilitates the development and expedites the review of drugs which treat severe conditions and fulfill an unmet medical need.5 Fast Track designation also enables Pfizer to continue to have ongoing discussions with the FDA on the development of its S. aureus vaccine.