Osteal Therapeutics announced positive 12-month results from its APEX clinical trials of VT-X7 KIT (vancomycin hydrochloride and tobramycin sulfate for irrigation/irrigation system) in patients with periprosthetic joint infections (PJI) of the hip or knee. The data, presented at the 2024 American Association of Hip and Knee Surgeons (AAHKS) annual meeting, demonstrated a statistically significant and clinically meaningful treatment effect compared to the current standard of care, two-stage exchange arthroplasty.
The APEX clinical program enrolled 152 patients across 23 centers in the U.S., randomizing them to either VT-X7 KIT or the standard two-stage exchange. The primary endpoint was treatment success at 12 months, defined by MSIS Tier 1 criteria.
Key Findings from the APEX Trials
The results showed a 19% net treatment effect in favor of VT-X7 KIT, with a 71% success rate compared to 52% in the control group (p<0.05). Furthermore, the median time to revision arthroplasty was significantly shorter in the VT-X7 KIT group (7 days) compared to the control group (98 days). Patients treated with VT-X7 also experienced a 62-minute reduction in overall procedure time during revision arthroplasty.
According to Dr. Nicolas S. Piuzzi, MD, of the Cleveland Clinic Foundation and Principal Investigator for the APEX-2 clinical study, "The APEX clinical program results are impressive, demonstrating a clinical advantage of rapid exchange arthroplasty with target site irrigation and providing surgeons with a promising, transformative approach to treating PJI, one that addresses the need to expedite infection eradication and allow patients to reclaim their lives."
Addressing the Burden of Periprosthetic Joint Infection
PJI affects over 40,000 people in the U.S. annually and is a severe complication of joint replacement surgery. The infection, characterized by bacterial colonization of the joint prosthesis and biofilm formation, often requires multiple surgeries and prolonged antibiotic courses. Current treatments, such as two-stage exchange arthroplasty, can take an average of 16 weeks and have a success rate under 50% after 12 months.
VT-X7 KIT is designed to deliver therapeutic concentrations of vancomycin and tobramycin directly to the joint space, targeting the bacterial biofilms responsible for PJI. The 7-day therapy aims to provide a rapid and reliable treatment option. In clinical studies, 100% of patients treated with VT-X7 received a new permanent joint prosthesis in seven days, with >90% remaining infection-free after one year. The FDA has granted VT-X7 Breakthrough Therapy, Orphan Drug, Fast Track, and Qualified Infectious Disease Product designations.
Implications for PJI Treatment
The positive results from the APEX trials suggest that VT-X7 KIT could offer a significant improvement over the current standard of care for PJI. By reducing the time to revision arthroplasty and the overall burden of infection, VT-X7 KIT has the potential to improve patient outcomes and quality of life.
