MMA Embolization With NeoCast for Subacute and Chronic Subdural Hematoma (RADIANT)

Pivotal Study of the Treatment of Symptomatic Subacute and Chronic Subdural Hematoma Via Middle Meningeal Artery Embolization With the NeoCastTM Embolic System (RADIANT)

The purpose of this study is to evaluate the safety and efficacy of embolization of the middle meningeal artery (MMA) using the NeoCast Embolic System for treatment of symptomatic subacute or chronic subdural hematoma (SDH) adjunctive to surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Subdural Hematoma
• Intervention / Treatment: Device: NeoCast Embolic System; Device: Onyx LES, an FDA-Approved Commercial Liquid Embolic

Detailed Description

This is a prospective, multi-center, randomized, controlled, single-blind pivotal trial to evaluate the safety and effectiveness of the NeoCast Embolic System in embolization of the middle meningeal artery (MMA) in surgically treated patients with symptomatic subacute or chronic SDH. Three hundred sixty participants will be randomized in a 2:1 ratio to be embolized with either the Arsenal Medical NeoCast Embolic System or Onyx LES, an FDA-approved commercial embolic. The Primary Effectiveness Endpoint will be measured at the 90-day timepoint post-treatment. Participants will be followed through 180 days.

• Study Type: Interventional
• Enrollment (Estimated): 360
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Carol Pekar, MBA; Phone Number: 508-523-5456; Email: cpekar@arsenalmedical.com

Study Locations

• United States
  • Connecticut
    • New Haven, Connecticut, United States, 06519
      • Yale Neurosciences Institute
  • Washington
    • Seattle, Washington, United States, 98104
      • University of Washington Medicine - Harborview Medical Center

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Participant whose age is ≥ 18 and ≤ 90 years;
• Pre-morbid mRS ≤ 2;
• Confirmed diagnosis of subacute or chronic subdural hematoma that measures ≥10 mm in greatest thickness;
• Participant presents with one or more of the following corroborating neurological symptoms: headache; cognitive decline; speech difficulty; gait impairment or imbalance; focal neurological deficit; and/or seizure, within the last 30 days;
• Participant is planned for middle meningeal artery embolization within ±7 days of surgical evacuation of hematoma via burr hole or craniotomy;
• Participant or Legally Authorized Representative/Person Responsible for consenting on their behalf understands the nature of the procedure, consents to participation in the study and provides a signed informed consent form;
• Participant (woman of child-bearing potential) with a current negative pregnancy test who has agreed to an appropriate method of contraception throughout the trial;
• Participant is willing to return to the investigational site for follow-up visits.

Exclusion Criteria:

• Diagnosed with acute SDH
• Participant with prior embolization of either MMA
• Participant with urgent or emergent (within 1 hour of assessment) subdural hematoma evacuation needed
• Participant with bilateral SDH where both sides require surgery or contralateral SDH >5mm in greatest thickness
• Participant identified with potentially dangerous anatomic variations leading to increased procedural risk, risk of incomplete embolization, or unsafe access for MMA embolization (i.e., MMA originating from ophthalmic artery)
• Participant who presents with a meningioma ≥1 cm or < 1 cm with mass effect
• Subjects with conditions placing them at high-risk for ischemic stroke who cannot be taken off anticoagulants for at least 7 days post-surgery
• Participant currently undergoing radiation therapy for carcinoma or sarcomas of the head or neck region
• SDH developed due to underlying condition or structure pathology (e.g., dural AV fistula, AVM, tumor, arachnoid cyst, ventriculoperitoneal shunt, spontaneous intracranial hypotension or previous craniotomy)
• Presumed microbial superinfection
• Participant who is breastfeeding
• Participant with life expectancy of <1 year
• Participants with acute renal impairment that the investigator assesses could be at risk for contrast induced nephropathy
• Participant with a life-threatening allergy to radiographic contrast (unless treatment for allergy is tolerated or can be managed medically)
• Participant is allergic to any of the materials used in the NeoCast device or the Onyx LES commercial embolic device
• Participant who is currently participating or planning to participate within 6 months in another clinical research 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: NeoCast Embolic System; Participants randomized to the NeoCast arm will have their MMA embolized with NeoCast adjunctive to surgery	Device: NeoCast Embolic System; NeoCast will be used to embolize a participant's middle meningeal artery in an endovascular procedure before or after adjunctive surgery to drain the hematoma
Active Comparator: Onyx LES FDA-Approved Commercial Liquid Embolic; Participants randomized to the active comparator control arm will have their MMA embolized with Onyx LES, an FDA-approved commercial liquid embolic adjunctive to surgery	Device: Onyx LES, an FDA-Approved Commercial Liquid Embolic; Onyx LES, an FDA-approved commercial liquid embolic, will be used to embolize a participant's middle meningeal artery in an endovascular procedure before or after adjunctive surgery to drain the hematoma; Other Names: Active Comparator Arm

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety Outcomes including Device-related or Procedure-related Serious Adverse Events	CEC-adjudicated safety outcomes in both arms including: Incidence of device-related Serious Adverse Events; Incidence of embolization procedure-related Serious Adverse Events; Incidence of device-related neurological deaths or disabling strokes within 30 days of embolization procedure; Incidence of device-related Adverse Events	180 days post-treatment
Comparison of NeoCast arm vs. Onyx LES arm for a composite endpoint of treatment failure events	The Primary Effectiveness Endpoint is a non-inferiority comparison of the NeoCast and Onyx LES groups for treatment failure as defined by the occurrence of any of the following events: Residual or re-accumulation of the SDH (≥10 mm) on 90-day scan post-treatment (assessed by a blinded, independent Imaging Core Lab);; Re-operation (after index procedure) or surgical rescue within 90 days post-treatment (CEC adjudicated);; Any new, major disabling stroke, myocardial infarction (MI) or death from any (neurological) cause within 90 days post-treatment (CEC adjudicated)	90 Days post-treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Superiority evaluation for successful distal penetration comparing NeoCast arm to the Onyx LES active comparator arm	Superiority evaluation for successful distal penetration comparing NeoCast arm to the Onyx LES active comparator arm	Peri-procedural
Superiority evaluation for successful embolization comparing NeoCast arm to the Onyx LES active comparator arm	Superiority evaluation for successful embolization comparing NeoCast arm to the Onyx LES active comparator arm	90 days post-treatment
Superiority evaluation of complete hematoma resolution at 180 days comparing the NeoCast arm to the Onyx LES active comparator arm	Superiority evaluation of complete hematoma resolution at 180 days comparing the NeoCast arm to the Onyx LES active comparator arm	180 days post-treatment
Superiority evaluation of percent hematoma volume reduction at 30 days compared to post-treatment timepoint comparing the NeoCast arm to the Onyx LES active comparator arm	Superiority evaluation of percent hematoma volume reduction at 30 days compared to post-treatment timepoint comparing the NeoCast arm to the Onyx LES active comparator arm	30 days post-treatment

Collaborators and Investigators

• Sponsor: Arsenal Medical, Inc.
• Investigators: Principal Investigator: Charles Matouk, MD, Yale Neurosciences Institute; Principal Investigator: Michael Levitt, MD, University of Washington Medicine - Harborview Medical Center

Publications and helpful links

General Publications

• Pham QP, Groom JV 2nd, Sadasivan C, Fiorella DJ, Madoff DC, Guo LJ, Fornaciari M, Guertin C, Wiltsey C, Core L, Merlo J, Wustenberg W, Virmani R, Arthur AS, Langer RS, Whitesides GM, Sharma U. An In Situ Curing, Shear-Responsive Biomaterial Designed for Durable Embolization of Microvasculature. Adv Healthc Mater. 2025 Jun;14(15):e2404011. doi: 10.1002/adhm.202404011. Epub 2025 Mar 11.

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): April 1, 2028

Study Registration Dates

• First Submitted: April 6, 2026
• First Submitted That Met QC Criteria: April 14, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

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

More Information

Terms related to this study

• Keywords: Hematoma; Chronic subdural hematoma (cSDH); Subacute subdural hematoma; Subdural hematoma (SDH); Middle Meningeal Artery (MMA) Embolization
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Wounds and Injuries; Pathologic Processes; Chronic Disease; Disease Attributes; Hemorrhage; Craniocerebral Trauma; Trauma, Nervous System; Intracranial Hemorrhages; Intracranial Hemorrhage, Traumatic; Pathological Conditions, Signs and Symptoms; Hematoma, Subdural; Hematoma, Subdural, Chronic; Hematoma
• Other Study ID Numbers: EMBO-03

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