The STRIVE trial is designed 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.
Surgical Site Infections (SSIs) caused by S. aureus account for about 20% of all SSIs in the US, and are associated with an estimated annual treatment cost of $12.3bn in the US.
Compared to non-infected patients, patients who suffer such infections due to antibiotic resistant (MRSA) or antibiotic sensitive (MSSA) S.aureus have worse clinical outcomes, including increased mortality.
Pfizer Vaccine Research and Development senior vice-president and chief scientific officer Dr Kathrin Jansen said: "We are pleased to take this important next step in the development of our S. aureus vaccine.
"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."
Around 2600 subjects will be enrolled in the trial and its primary outcome will measure the number of people 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.
The trial’s 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.
The company noted that the Phase IIb trial is expected to be completed in 2017.
In February, the US Food and Drug Administration (FDA) has granted fast track designation for Pfizer’s S. aureus vaccine.
The company’s multi-antigen S. aureus vaccine is designed to prevent a wide-range of clinical disease manifestations, caused by S. aureus, by facilitating killing of the bacteria at the early stages of invasive infection by targeting multiple virulence mechanisms.
Image: Pfizer world headquarters. Photo: courtesy of Jim.henderson.