Peptide-enhanced bone graft outperforms autograft at two years

I-factor peptide-enhanced bone graft
P-15 enhances bone formation by facilitating cellular attachment. Image: Cerapedics

A prospective, multicentre trial has found that a peptide-enhanced bone graft is non-inferior compared to local autograft bone. In addition, the bone graft outperformed autograft bone for overall success measures.

The randomised single-blinded study reports that the use of I-factor (Cerapedics) is “effective and safe” in anterior cervical discectomy and fusion (ACDF), and results in similar two-year outcomes for patients who received the “gold standard” local autograft procedure. An analysis of the success rate for all factors was regarded as clinically relevant.

Clinical outcomes of the trial were determined from radiological, clinical, and patient-reported factors.

Lead author Paul Arnold, (Department of Neurosurgery, University of Kansas Medical Center, Kansas City, USA) told Spinal News International, “We have excellent two-year data that show that [I-factor] works very well.”

There are several commercially-available bone graft substitutes which aim to replicate autograft bone, including those known as biologic bone grafts. Biologic bone grafts are often classified as drug/device combinations due to their potent ability to influence the formation of new bone (eg. growth factors such as recombinant human bone morphogenic protein-2 [rhBMP-2]); however, these potent exogenous growth factors are also associated with significant clinical complications. Newer technologies such as stem cell-derived bone grafts have generated excitement, but there remains a lack of evidence for their efficacy.

I-factor is a biologic bone graft that mimics the biological activity of a 15-amino acid peptide (P-15) sequence naturally found in human type I collagen to significantly increase the cell binding of osteogenic precursor cells to encourage rapid, early bone formation. The P-15 peptide is absorbed onto anorganic bone material (ABM) and, according to Arnold, “it is very easy to use, it is a unique biologic, and it has excellent clinical and safety profiles.”

Peptide-enhanced bone graft
Cells bind to the P-15 domain and organise the matrix by tractional forces. Image: Cerapedics

The P-15 ABM technology has been used in dental applications in approximately 500,000 cases since the 1990s. I-factor has been utilised successfully in orthopaedic and spinal applications since its CE mark in 2008 and PMA approval in November 2015.

At two-year follow-up, the control group that received the traditional local autograft bone had a fusion rate of 94.44%, compared to the study arm that received I-factor, which had a fusion rate of 97.30% (p=0.2513). Additionally, patients in the investigative arm had a Neck Disability Index (NDI) improvement of 28.30, compared to an improvement of 26.95 across the control arm (p=0.1448).

The derived composite success rate—determined by the fusion rate, neurological success rate, an NDI improvement >15, and re-operation rate—was greater in the I-factor subjects compared to the autograft group (69.83% and 56.35% respectively, p=0.0302).

Statistical assessment of the study results showed that there was no significant difference in the rate of adverse events between the two study groups. However, there were six cases of superficial infection in the I-factor group, compared to none in the control group (p=0.03). Autograft subjects underwent subsequent cervical spine surgeries on the same level at a rate of 8.44%, while the I-factor subjects underwent surgery on the same level at a rate of 3.73%.

I-factor peptide-enhanced bone graft
P-15/ABM expedities the ingrowth of bone by promoting stem cell migration. Image: Cerapedics

The fusion rate with I-factor was higher than that reported in the autograft control groups of other pivotal studies using similar methodologies and criteria.

Arnold said that I-factor will “[add] to the surgeon’s ability to achieve fusion in the cervical spine.”

He added, “We are looking forward to testing [I-factor] in other areas of the spine,” paving the way for validation beyond ACDF procedures.

This article was originally published in issue 45 of Spinal News International.


Please enter your comment!
Please enter your name here