Evaluation of Cranial Flap Fixation With Montage Flowable Settable Bone Paste

Montage Flowable Settable Bone Paste is a self-setting calcium phosphate cement indicated for use in the repair of neurosurgical burr holes, contiguous craniotomy cuts and other cranial defects with a surface area no larger than 25cm2. It is also intended to be used for the fixation of cranial bone flaps following craniotomy. The MONTAGE Flowable device comprises two separate components of paste-like consistency containing granular calcium phosphate, calcium stearate, vitamin E acetate, a triglyceride, polyalcohols and a mixture of a lactide-diester and polyester-based polymers. When mixed together in the applicator tip, the components of the MONTAGE Flowable device form a cohesive paste-like material that adheres to the bone surface and remains in place following application. The resulting hardened, resorbable material is primarily calcium phosphate. The components must be mixed immediately prior to use.

Study Overview

• Status: Not yet recruiting
• Conditions: Post-operative Complications; Cranioplasty; Cranial Bone; Cranial Fixation; Adhesive Bone Cement
• Intervention / Treatment: Device: Cranial flap placement and fixation using only Montage Flowable Settable Bone Paste; Device: Metallic fixation hardware

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Aniq Darr, Ph.D.; Phone Number: 18554759175; Email: Darr@Abyrx.com
• Study Contact Backup: Name: Alyssa McDermott, M.S.; Phone Number: 8554759175; Email: McDermott@Abyrx.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Male or female > 18 years of age
2. Undergoing a cranial procedure in supratentorial location
3. Width of craniotomy kerf line <3mm for than 75% of the bone flap border

Exclusion Criteria:

1. Subject requires a procedure involving a translabyrinthine, transsphenoidal, transoral approach, or any procedure that penetrates the air sinus or mastoid air cells.
2. Subject has clinically significant hydrocephalus or clinical evidence of altered CSF dynamics.
3. Subject has undergone a previous, open intracranial neurosurgical procedure in the same anatomical location. (Note: stereotactic biopsy was not exclusionary).
4. Subject requires a craniectomy (the bone flap is not replaced during the current surgery).
5. Subject had radiation treatment to the surgical site, or standard fractionated radiation therapy was planned post index-procedure. (Note: stereotactic radiosurgery prior to the planned index procedure was not an exclusion criterion.)
6. Subject requires a craniotomy across the sinus for which Montage Flowable is applied adjacent to or within the sinus to fixate the cranial flap.
7. Subject has a condition with anticipated survival shorter than six months.
8. Subject has undergone chemotherapy treatment, excluding hormonal therapy, within three weeks prior to the planned index procedure, or use of intracavitary chemotherapy wafer (BCNU) was planned, or chemotherapy treatment was planned within two weeks after the index procedure was performed.
9. Standard use of peri-operative steroids (i.e., corticosteroids) is permitted. Chronic steroid use (defined as daily use of corticosteroids for ≥ 8 weeks) for the purposes of reducing the side effects of chemotherapy and/or radiation therapy for cancer is not exclusionary unless the patient is deemed by the investigator to be suffering from steroid toxicity (i.e., Cushing's syndrome) manifested by symptoms and signs such as thin skin, striae, easy bruising, muscle atrophy, upper body obesity, severe fatigue, etc. Use of corticosteroids on a chronic basis (as defined previously) for purposes other than decreasing the symptoms of systemic chemotherapy is exclusionary unless those steroids were discontinued 4 weeks prior to the planned index procedure.
10. Subject receives warfarin, heparin, other anticoagulant agents on a daily basis and pre-surgical, standard of care drug wash-out did not occur.
11. Subject is pregnant, breast-feeding, or intended to become pregnant during the course of the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Montage Flowable Settable Bone Paste; Fixation using Montage Flowable Settable Bone Paste exclusively	Device: Cranial flap placement and fixation using only Montage Flowable Settable Bone Paste; Experimental
Active Comparator: Control; Metallic fixation hardware	Device: Metallic fixation hardware; Control

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cranial flap immobility	Cranial flap immobility as determine by the neurosurgeon will be tabulated and compared between group	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Flap localization	Localization of the flap based on CT scan compared between groups.	12 months
Device-related adverse events	• Device related adverse events included all adverse events classified as definitely, probably, possibly, or undetermined relation to the device or procedure	12 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complications	Complication categories will also be tabulated and compared	12 months

Collaborators and Investigators

• Sponsor: Abyrx, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: July 29, 2025
• First Submitted That Met QC Criteria: July 29, 2025
• First Posted (Actual): August 5, 2025

Study Record Updates

• Last Update Posted (Actual): August 5, 2025
• Last Update Submitted That Met QC Criteria: July 29, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Cranioplasty; Settable bone paste; Adhesive cranial cement
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications
• Other Study ID Numbers: Abyrx PMRCT 25-001

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