Post Marketing Study of MagnetOs Easypack Putty Standalone Compared to Demineralized Bone Matrix or Fibers Mixed With Autograft in Patients Undergoing Posterolateral Lumbar Fusion (PROOF)

A Prospective, Randomized, Multi-Center Study to Assess the Safety and Performance of MagnetOs Easypack Putty Standalone Compared to Demineralized Bone Matrix or Fibers (DBX or Grafton) Mixed With Local Autograft in Patients Undergoing One to Two-Level Instrumented Posterolateral Lumbar/Thoracolumbar Fusion (PLF)

This is a phase IV post-marketing study for MagnetOs Easypack Putty. MagnetOs Easypack Putty is a synthetic bone graft extender product that is routinely used by surgeons as a treatment for patients with degenerative disc disease or spinal trauma undergoing spinal fusion surgery.

In this study, MagnetOs Easypack Putty will be used according to the latest U.S. Instructions For Use, standalone in the posterolateral spine.

Study Overview

• Status: Recruiting
• Conditions: Back Pain; Degenerative Disc Disease; Spine Fusion
• Intervention / Treatment: Device: MagnetOs Easypack Putty; Device: Demineralized Bone Matrix or Fibers mixed with local autograft bone

Detailed Description

In this study, following a screening period of a maximum of 30 days, 60 patients will undergo up to two-level instrumented posterolateral fusion (PLF) procedure. Prior to surgery, each patient will be randomized to receive MagnetOs Easypack Putty standalone on the assigned side of the spine and Demineralized Bone Matrix or Fibers mixed with local autograft bone on the other at the diseased levels. They will be followed up at discharge, Week 2, Month 3, Month 6, and Month 12. An interim analysis will be performed once 30 patients have completed their Month 6 visit and have measurements for the endpoints available to measure effectiveness. The primary endpoint will be analyzed at Month 12.

In this study, MagnetOs Easypack Putty will be applied according to the latest Instructions for Use approved in the United States. Specifically, MagnetOs Easypack Putty will be used standalone in patients up to two-level degenerative disc disease with segmental mechanical spinal instability requiring treatment with an instrumented posterolateral spine fusion procedure. The fusion procedure (PLF) will be left to the surgeon's discretion.

Radiographs will be obtained at Screening, Discharge, Month 3, Month 6 and Month 12. CT scans will only be obtained at Month 6 and Month 12.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Cesar Silva, MD; Phone Number: 9702156793; Email: cesar.silva@kurosbio.com

Study Locations

• United States
  • California
    • Irvine, California, United States, 92697
      • Recruiting
      • The Regents of the University of California- Irvine Campus
      • Contact: Michael Oh, MD; Email: ohm2@hs.uci.edu
  • Michigan
    • Grand Rapids, Michigan, United States, 49503
      • Recruiting
      • Corewell Health
      • Contact: Jason Squires, M; Email: Jason.Squires@corewellhealth.org
  • Missouri
    • St Louis, Missouri, United States, 63130
      • Recruiting
      • The Washington University
      • Contact: Principal Investigator, Mark Lambrechts, MD
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19107
      • Recruiting
      • Rothman Orthopaedic Institute
      • Contact: Principal Investigator, Jose Canseco, MD
  • Tennessee
    • Nashville, Tennessee, United States, 37209
      • Recruiting
      • Tennessee Orthopaedic Alliance
      • Principal Investigator: Ryan Snowden, MD
  • Washington
    • Seattle, Washington, United States, 98104
      • Recruiting
      • University of Washington
      • Principal Investigator: Christoph Hofstetter, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient is able to read/be read, understand, and provide written informed consent and has signed the Institutional Review Board (IRB) approved informed consent.
• Male or female patient ≥ 18 years old.
• Patients with segmental mechanical spinal instability requiring arthrodesis surgery.

Instability can be either caused by degenerative disc disease or by traumatic injury to the spinal column. Patient requiring a maximum of two-level instrumented posterolateral lumbar/thoraco-lumbar fusion (T11 - S1) will be enrolled. Mechanical instability is defined by the presence of one or more of the following:

1. instability (angulation ≥ 5 degrees or translation ≥ 3 mm on flexion/extension radiographs),
2. decreased disc height by > 2 mm, but dependent upon the spinal level
3. Grade II or more listhesis
4. TLICS equal or greater than 5

5. Unstable burst fracture

   • Failed conservative treatment (physical therapy, bed rest, medications, spinal injections, manipulations, or transcutaneous electrical nerve stimulation) for a minimum period of 3 months prior to study enrollment (if the patient undergoes elective surgery). Patients who have spinal instability (as defined above in inclusion criteria number three), caused by acute trauma requiring urgent surgical treatment are excluded from this criterion.

Exclusion Criteria:

• Requires > two-level fusion or expected to need secondary intervention within one year following surgery.
• Had prior PLF fusion or attempted PLF fusion at the involved levels.
• Had previous decompression at the involved levels.
• Women who are or intend to become pregnant within the next 12 months.
• To treat conditions in which general bone grafting is not advisable.
• In conditions where the surgical site may be subjected to excessive impact or stresses, including those beyond the load strength of fixation hardware (e.g. defect site stabilization is not possible).
• In case of significant vascular impairment proximal to the graft site.
• In case of severe metabolic or systemic bone disorders (e.g., osteogenesis imperfecta, history of or active Pott's disease, stage >4 renal disease or Paget's Disease) that affect bone or wound healing.
• In case of acute and chronic infections in the operated area (soft tissue infections; inflammation, bacterial bone diseases; osteomyelitis).
• When intraoperative soft tissue coverage is not planned or possible.
• Receiving treatment with medication interfering with calcium metabolism.
• Has degenerative disc disease (DDD) related to a benign or malignant tumor.
• Has history or presence of active malignancy.
• Has known substance abuse, psychiatric disorder, or a condition which, in the opinion of the investigator, may influence the healing or ability to comply with protocol requirements.
• Is involved in active litigation relating to his/her spinal condition.
• Has participated in an investigational study within 30 days prior to surgery for study devices.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: MagnetOs Easypack Putty; Interventions; Procedure: Instrumented posterolateral spine fusion; Device; MagnetOs Easypack Putty	Device: MagnetOs Easypack Putty; MagnetOs Easypack Putty used standalone in instrumented posterolateral fusion, 5cc-15c per spine level at the randomized assigned side.
Active Comparator: Demineralized Bone Matrix or Fibers (DBX or Grafton) mixed with local autograft bone; Interventions; Procedure: Instrumented posterolateral spine fusion; Device: Demineralized Bone Matrix or Fibers mixed with local autograft bone	Device: Demineralized Bone Matrix or Fibers mixed with local autograft bone; Demineralized Bone Matrix or Fibers (DBX or Grafton) mixed in a 1:1 vol% with local autologous bone graft used in instrumented posterolateral fusion, 5cc-15cc per level mixed with bone marrow aspirate/blood per spine level at the contralateral side.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radiographic Fusion by CT Scan	The rate of posterolateral lumbar/thoracolumbar fusion assessed by CT-scan at Month 12. Radiographic as determined by evidence of bridging trabeculae or continuous bony connection between the superior and inferior transverse processes.	Month 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radiographic Fusion by CT Scan	The rate of posterolateral lumbar/thoracolumbar fusion assessed by CT-scan at Month 6. Radiographic as determined by evidence of bridging trabeculae or continuous bony connection between the superior and inferior transverse processes.	Month 6
Radiographic Fusion by Plain Radiographs	The rate of posterolateral lumbar/thoracolumbar fusion assessed by plain radiographs.	Month 6, Month 12
Success Rate	Number of patients with secondary surgical interventions (SSI's) such as revisions, re-operations, removals, supplemental fixations, or any other procedure that adjusts or removes part of the original implant configuration with or without replacement of the components within 12 months of surgery.	Week 2, Month 3, 6, and 12
Functional Outcome by Oswestry Disability Index Questionnaire	Functional outcome by the Oswestry Disability Index questionnaire. Patient-completed questionnaire which gives a subjective percentage score of level of function (disability) in activities of daily living in those rehabilitating from low back pain. The lower the percentage the higher the patient's functionality. 0-20% minimal disability, 80-100% significant disability or bedridden.	Screening, Week 2, Month 3, 6, and 12
Back and Leg Pain by Visual Analog Pain Scale Questionnaire	Change in back and leg pain using Visual Analog Pain Scale (0-100). Patient-completed questionnaire scoring pain by using 100 mm line. Zero being no pain, 100 is worst pain imaginable.	Screening, Week 2, Month 3, 6, and 12
Neurologic Status by Physical Exam	Change in neurologic status by examination to document stable, improved, or deficits in condition. Stable or improved findings for lower extremities, specifically reflexes, muscle strength, sensory, and straight leg raise.	Screening, Week 2, Month 3, 6, and 12

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety Endpoint - number of patients with Serious Adverse Events	The number of patients with Serious Adverse Events from Screening up to Month 12 after surgery	12 Months
Safety Endpoint - number of patients with Adverse Events	The number of patients with Adverse Events from Screening up to Month 12 after surgery.	12 Months
Safety Endpoint - number of patients with Adverse Device Effects	The number of patients with Adverse Device Effects from Screening up to Month 12 after surgery.	12 Months
Safety Endpoint - number of patients with Device Related Complications	The number of patients with any complications considered to device related with 12 months after surgery.	12 Months
Health Economic - Duration of Surgery	Duration of surgery in minutes.	12 Months
Health Economic - Duration of Hospitalization	Duration of hospital stay in days.	12 Months
Health Economic - Return to Work	Time to return to work in days.	12 Months

Collaborators and Investigators

• Sponsor: Kuros Biosurgery AG
• Collaborators: Kuros BioSciences B.V.; Simplified Clinical Data Systems, LLC
• Investigators: Study Director: Cesar Silva, MD, Kuros BioSciences B.V.

Study record dates

Study Major Dates

• Study Start (Actual): December 6, 2024
• Primary Completion (Estimated): June 2, 2027
• Study Completion (Estimated): August 30, 2027

Study Registration Dates

• First Submitted: December 18, 2020
• First Submitted That Met QC Criteria: December 18, 2020
• First Posted (Actual): December 22, 2020

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Degenerative Disc Disease; Spine Fusion
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Bone Diseases; Musculoskeletal Diseases; Spinal Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Back Pain; Intervertebral Disc Degeneration
• Other Study ID Numbers: MAG-920-023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No