The first patient has been enrolled in Kuros Biosciences’ global ASTRA (Ankle Subtalar arThrodesis Randomized Assessment) study—a prospective, randomized, trial to assess the safety and performance of MagnetOs compared to autograft in patients undergoing hindfoot or ankle fusions. Subtalar fusion will be among the surgical approaches included in the study.

“Enrollment of the first patient in the ASTRA trial marks another important milestone in our Kuros mission to expand the clinical reach of MagnetOs,” Kuros Biosciences CEO Chris Fair stated. “Building on the strength of our ongoing Level I PROOF and PRECISE clinical trials in posterolateral spine fusion, ASTRA extends our clinical evidence portfolio into foot and ankle. We’re proud to continue advancing the science of bone healing into new anatomical regions where surgeons need reliable solutions for their patients.”

The single-blinded, controlled ASTRA study is part of Kuros’ expanding global extremities strategy and represents the company’s commitment to build clinical evidence across various surgical applications. This international trial will include sites in the United States, Australia, New Zealand, Europe, and/or the Middle East.

Approximately 126 patients undergoing hindfoot or ankle fusions will prospectively be enrolled and randomized to be treated in either the MagnetOs arm (MagnetOs Putty or MagnetOs Easypack Putty used standalone, not mixed with other bone grafting materials) or the autograft arm.

“We’re excited to participate and get the enrollment underway in this global study,” said Dr. Jesse Doty, orthopedic surgeon and principal investigator at Erlanger Orthopaedics in Chattanooga, Tenn. “Successful bone fusion in complex hindfoot and ankle procedures can be challenging, especially when autograft availability or quality is limited. I’m excited to be a part of this Level I study looking at the efficacy of an advanced bone graft in my hindfoot fusion patients.”

The study name ASTRA was inspired by astragalus, the historical term for the talus or ankle bone; it underscores the study’s focus on improving outcomes in ankle and hindfoot fusion procedures.

Growing bone with MagnetOs gives surgeons confidence in delivering predictable fusion outcomes.¹ In a Level I human clinical study published in Spine, MagnetOs achieved nearly twice the fusion rate of autograft (79% vs. 47%) in posterolateral fusions (PLFs).¹ Among active smokers—who comprised one in five patients—the fusion difference between MagnetOs and autograft was even more dramatic.*†^1,2 MagnetOs grows bone on its own thanks to NeedleGrip—a proprietary submicron surface technology that harnesses the immune system to stimulate bone growth, without added cells or growth factors.§‡^4-6 Ready-to-use, easy to mold, and reliably staying put, MagnetOs carries no intrinsic risk of human tissue-related disease transmission and is cleared by the U.S. Food and Drug Administration (FDA) for use throughout the spine, including interbody procedures. ¶^7-12

Kuros Biosciences develops and delivers biologic technologies. With locations in the United States, Switzerland ,and the Netherlands, the company is listed on the SIX Swiss Exchange. Its first commercial product, MagnetOs, is an advanced bone graft that has been used on five continents.

* 19 of initial 100 patients were active smokers.
† Radiographic fusion data of the smoker subgroup were not statistically analyzed as a subgroup and were not included in the peer-reviewed publication of the study.
‡ Results from in-vitro or in vivo laboratory testing may not be predictive of clinical experience in humans.
§ MagnetOs is not cleared by the FDA or TGA as an osteoinductive bone graft. 
¶ MagnetOs must also be used with an intervertebral body fusion device cleared by FDA for use with a bone void filler. MagnetOs Flex Matrix must be hydrated with BMA and mixed with autograft in posterolateral spine and intervertebral disc space. MagnetOs Granules must be hydrated with blood in the intervertebral disc space.

References
¹ Stempels, et al. Spine. 2024;49(19):1323-1331.
² Van Dijk, LA. 24th SGS Annual Meeting (Swiss Society of Spinal Surgery). Basel, Switzerland. Aug 2024.
³ Data on file. MagnetOs Putty and MagnetOs Easypack Putty.
⁴ Van Dijk, et al. eCM. 2021;41:756-73.
⁵ Van Dijk, et al. J Immunol Regen Med. 2023;19:100070.
⁶ Duan, et al. eCM. 2019; 37:60-73.
⁷ Instructions for Use (IFU) MagnetOs Granules.
⁸ Instructions for Use (IFU) MagnetOs Putty.
⁹ Instructions for Use (IFU) MagnetOs Easypack Putty.
¹⁰ Instructions for Use (IFU) MagnetOs Flex Matrix.
¹¹ Instructions for Use (IFU) MagnetOs MIS.
¹² Data on file. MagnetOs Putty and MagnetOs Easypack Putty.