Superiority in Speed-to-Fusion with P-15 Peptide Enhanced Bone Graft as Compared to Autograft in TLIF: Analysis of Radiological Outcomes of a Multicenter, Prospective and Randomized Controlled Trial

Introduction: Autologous bone is considered the gold standard in spine fusion. This abstract presents the radiological fusion outcomes from a multicenter RCT comparing ABM/P-15 Matrix, an FDA breakthrough device, to local autograft as the control in treating degenerative disc disease using TLIF.

Methods: 290 patients, aged 22-80 years, were randomized 1:1 to either ABM/P-15 Matrix or local autograft during single-level TLIF. Fusion assessments occurred at 6-, 12-, and 24-months, by two independent radiologists, and defined as evidence of continuous bridging trabecular bone from endplate to endplate by high resolution thin-slice CT scans. Once fusion was confirmed, it was assumed fusion had occurred at all subsequent time points. Time-to-fusion was pre-specified as a superiority effectiveness endpoint and tested using the Kaplan-Meier survival rate.

Results: 141 patients received ABM/P-15 Matrix and 149 received autograft. 90.1% in the ABM/P-15 Matrix group and 87.2% of patients in the autograft group were available for the 24-month imaging follow-up. Significantly more patients treated with ABM/P-15 Matrix than autograft achieved fusion at 6-months (59.7% vs 28.7%, respectively), 12-months (72.9% vs 44.1%, respectively), and 24-months (84.3% vs 58.5%, respectively) (p < 0.0001 for all). The ABM/P-15 Matrix group was 44% more likely to fuse by 24-months compared with the autograft group. The Kaplan-Meir survival rate showed robust statistical evidence that the time-to-fusion is shifted toward earlier times for ABM/P-15 Matrix relative to autograft, demonstrating superiority of ABM/P-15 Matrix for faster time-to-fusion (p < 0.0001).

Conclusion : Significantly higher fusion rates were observed in patients treated with ABM/P-15 Matrix compared to those treated with autograft. The difference in fusion rates were statistically higher in favor of ABM/P-15 Matrix at 6-, 12- and 24-month follow-up. The results from these analyses demonstrate that ABM/P-15 Matrix promotes faster fusion and statistically superior earlier time-to-fusion than local autograft in instrumented TLIF.