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Osteal Therapeutics, Inc. Completes Enrollment in APEX Phase 2 Clinical Trial of VT-X7 for Periprosthetic Joint Infection

Six-month outcomes are expected in second quarter of 2023.

Dallas, November 4, 2022 – Osteal Therapeutics, Inc. (“Osteal”), a clinical-stage biopharmaceutical company developing a new category of combination therapies for musculoskeletal infections, announced today it has completed enrollment of 76 subjects for its U.S. Phase 2 clinical trial of VT-X7 for the treatment of periprosthetic joint infections of the hip or knee. Results from this trial will be used to support a U.S. New Drug Application following completion of Osteal’s clinical development program.  


“We believe the tremendous clinical enthusiasm we saw in the APEX study strongly reflects the significant unmet medical need in this patient population. The APEX clinical program will be an important element in a robust safety and efficacy database to support our VT-X7 NDA,” said David Thompson, President and Chief Executive Officer of Osteal. “We are grateful to the patients, investigators and the Osteal team members who made achievement of our enrollment goals possible.”


The clinical study, known as APEX (Abbreviated Protocol for Two-Stage Exchange), is a prospective, randomized, controlled trial being conducted at 17 sites across the U.S. It is intended to assess the safety and efficacy of VT-X7, a drug/device combination product that locally delivers, via irrigation, highly targeted antibiotic therapy to the hip or knee during an accelerated seven-day interstage period of a two-stage exchange arthroplasty. Patients who received VT-X7 therapy will be compared to a control group who underwent traditional two-stage exchange arthroplasty involving a temporary antibiotic-impregnated cement spacer and adjuvant systemic antibiotics. Efficacy is defined as treatment success per Musculoskeletal Infection Society guidelines.


Osteal expects to enroll the first subject in its next Phase 2 study, known as APEX-2, in November 2022. APEX-2 has a similar design to APEX and is intended to build upon the safety and efficacy evidence obtained from APEX. The company hopes to complete enrollment of APEX-2 in the third quarter of 2023.


About Periprosthetic Joint Infection (PJI)

Affecting over 40,000 people in the U.S annually, periprosthetic joint infection (PJI) is a rare but potentially devastating complication of joint replacement surgery in which pathogenic bacteria colonize the joint prosthesis forming difficult to remove structures called biofilms. Biofilm infections are challenging to resolve, requiring long, invasive and expensive treatments that are often unsuccessful, resulting in high rates of permanent disability and early death. Recent evidence demonstrates that the current gold standard for treatment of PJI, two-stage exchange arthroplasty, takes an average of 16 weeks and has a success rate under 50% after 12 months, highlighting the unmet need for faster more reliable treatment options.


About VT-X7

VT-X7 (VT-X7 spacer device, vancomycin hydrochloride and tobramycin sulfate) for irrigation is a novel drug/device combination product designed to deliver therapeutic concentrations of vancomycin and tobramycin, well-established, broad-spectrum antibiotics, directly to the joint space and surrounding tissue to treat chronic periprosthetic joint infection. VT-X7 is a seven-day therapy designed to address the unmet clinical need for a rapid, reliable treatment for these rare but challenging infections. In a Phase 2 clinical trial of vancomycin and tobramycin joint irrigation, 100% of patients were treated and received a new permanent joint prosthesis in seven days with 93% remaining infection free at one year. Osteal Therapeutics recently completed enrollment of its Phase 2 APEX clinical study, a randomized controlled trial of VT-X7 compared to the current standard of care for treatment of PJI, two-stage exchange arthroplasty. The FDA granted VT-X7 orphan drug, fast track, and qualified infectious disease product designations. This initial application of VT-X7 represents a first-of-its-kind, multibillion dollar opportunity to dramatically improve outcomes for an underserved patient population.

About Osteal Therapeutics, Inc.

Osteal Therapeutics is a privately held, clinical-stage biopharmaceutical company developing novel musculoskeletal therapeutics to treat orthopedic infections and their consequences. The company is leveraging the ability of concentrated, locally delivered antimicrobials to treat the bacterial biofilms typically responsible for musculoskeletal infections while minimizing off-target tissue exposure and associated adverse effects. Osteal employs a low-risk development strategy by using approved drugs with long histories of safety and efficacy as candidates for new routes of local delivery. The company’s lead candidate, VT-X7, is in Phase 2 development to treat periprosthetic joint infections, a serious complication of joint replacement surgery. For more information, please visit:

Corporate Contact:

Todd Saunders

Vice President of Marketing

Osteal Therapeutics, Inc.


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