P-15 Peptide Enhanced Bone Graft in Transforaminal Lumbar Interbody Fusion: A Randomized, Controlled, Investigational Device Exemption Study Demonstrating Improved Composite Clinical Success

Abstract

Study design: Prospective, multicenter, single-blind, randomized, controlled pivotal study. Objective: To evaluate whether P-15L (PearlMatrix P-15 Peptide Enhanced Bone Graft) is noninferior in effectiveness to local autograft when applied in single-level instrumented transforaminal lumbar interbody fusion (TLIF). Summary of background data: P-15L, an FDA-designated Breakthrough Drug-Device, is a composite drug-device combination bone graft containing P-15, a 15-amino acid polypeptide, which enhances cell binding, proliferation, and differentiation, resulting in bone formation. Materials and methods: Skeletally mature patients, aged 22 to 80 years, with degenerative disc disease (DDD) were randomized 1:1 to P-15L (investigational) or to the local autograft (control) during single-level TLIF with a polyetheretherketone (PEEK) cage and supplemental pedicle screw fixation. The primary outcome was composite clinical success (CCS) at 24 months, defined as: no index level secondary surgical procedures; achievement of fusion; ≥15-point improvement in Oswestry low back pain disability questionnaire (ODI) from baseline; no new or worsening persistent neurological deficit relative to baseline; and no device-related serious adverse events (SAEs). Results: A total of 290 patients were enrolled at 33 sites: 141 (48.6%) received P-15L, and 149 (51.3%) received local autograft. P-15L was noninferior ( P <0.0001) and superior ( P =0.002) to autograft with respect to CCS, with 55.5% of the investigational group achieving composite clinical success compared with 37.5% of the control group. P-15L had a 25.8% higher fusion rate as compared with autograft for the CCS at 24 months (84.3% vs. 58.5%, respectively). Device-related SAE rates were similar in both groups. Conclusion: P-15L was superior to local autograft in achieving clinical success at 24 months. Furthermore, P-15L produced a significantly higher fusion rate as compared with autograft. No meaningful clinical differences were found in the incidence of device-related SAEs. P-15L appears to be a safe and effective option for TLIF.