By: 27 June 2024
Kuros Biosciences announces peer-reviewed publication of MagnetOs MAXA level 1 study outcomes in spine

Kuros Biosciences, a manufacturer of bone healing technologies, recently announced the publication of a peer-reviewed manuscript that details the clinical data of its MAXA Level 1 prospective, multi-center, randomized, intra-patient controlled clinical study in Spine1.

Published clinical results of “Efficacy of Biphasic Calcium Phosphate Ceramic with a Needle-shaped Surface Topography Versus Autograft in Instrumented Posterolateral Spinal Fusion: A Randomized Trial” include fusion data on 91 patients and 128 segments with 1-year follow-up after surgery. As previously reported and now detailed in the peer-reviewed publication, the data demonstrates:

  • MagnetOsTM effectiveness as a standalone* alternative to autograft in challenging posterolateral fusions (PLF);
  • Nearly double the fusion rate as compared to autograft in PLF, showing a 79% overall fusion rate with MagnetOs as independently measured with fine-cut CT, compared to 47% for autograft, which included difficult-to-treat patients of current and former smokers (n=19 and 35 respectively); and
  • Noninferiority of MagnetOs versus autograft per study design, with primary outcome analysis even indicating MagnetOs superiority.

“We are extremely pleased to share the results of the MAXA study with the medical community,” said Moyo C. Kruyt, MD, PhD, lead researcher in the MAXA study. “The MAXA study demonstrates for the first time that an advanced synthetic bone substitute likely performs better than the current gold standard autograft in a challenging posterolateral fusion location.”

Chris Fair, Chief Executive Officer of Kuros, said, “Kuros is committed to supporting clinical research and providing evidence-based solutions for next generation bone healing technologies.  This study’s acceptance and publication in Spine is proof of that commitment.” Fair continued, “We commend Professor Kruyt and his team for their independent efforts and their desire to provide the spine community and their patients with a robust level 1 study that supports the use of MagnetOs for difficult to treat patients and highlights a viable alternative to autograft.”

The publication, which includes additional details such as study design, patient demographics, inclusion/exclusion criteria, and complications reported in the study, can be accessed on the Spine website and is also available on the Kuros Biosciences website.



1.    Stempels, H. et al., “Efficacy of biphasic calcium phosphate ceramic with a needle-shaped surface topography versus autograft in instrumented posterolateral spinal fusion: A randomized trial.” Spine. June 17, 2024.
2.    Van Dijk, et al. eCM. 2021; 41:756-73.
3.    Duan, et al. eCM. 2019; 37:60-73.
4.    Van Dijk, et al. Clin Spine Surg. 2020;33(6): E276-E287.
5.    Van Dijk, et al. JOR Spine. 2018 ; e1039
6.    Van Dijk, et al. J Biomed Mater Res. Part B: Appl Biomater.
*MagnetOs was mixed with venous blood
†Results from in vivo laboratory testing may not be predictive of clinical experience in humans. For important safety and intended use information please visit
‡MagnetOs is not cleared by the FDA or TGA as an osteoinductive bone graft.
§MagnetOs has been proven to generate more predictable fusions than two commercially available alternatives in an ovine model of posterolateral fusion.

About the MAXA Trial  
The MAXA study is a 100-patient multicenter, observer blinded, randomized, intra-patient controlled, non-inferiority trial with intra-patient comparisons. Adult patients qualifying for instrumented posterolateral spinal fusion of one to six levels in the thoracolumbar and lumbosacral region (T10-S2) with the use of autograft were included and posterolateral lumbar/thoracolumbar fusion was assessed by fine-cut CT-scan 12 months after surgery. According to a randomization scheme, MagnetOs was implanted on one side of the spine and the gold standard autograft (consisting of at least 50% bone harvested from the iliac crest mixed with local bone) was implanted on the other side of the spine. The investigators were blinded to the side assigned to the grafts until just prior to graft application.  Thereby, each patient serves as its own control. More details can be found at (NCT03625544). Fusion performance of MagnetOs was tested with a noninferiority margin of 15%.

The MAXA clinical trial was funded via an unrestricted research grant from Kuros Biosciences.  Unrestricted research grants provide funding to clinical investigators with an interest in advancing the knowledge and understanding of certain technologies. These grants are donations in the form of flexible funding that can be directed toward whatever program, project, or expense the investigator chooses.