pRESET Thrombectomy Device

K222848 · Phenox Limited · POL · Jan 20, 2023 · Neurology

Device Facts

• Record ID: K222848
• Device Name: pRESET Thrombectomy Device
• Applicant: Phenox Limited
• Product Code: POL · Neurology
• Decision Date: Jan 20, 2023
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 882.5600
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

1. The pRESET® Thrombectomy Device is indicated for use to restore blood flow in the neurovasculature by removing thrombus for the treatment of acute ischemic stroke to reduce disability in patients with a persistent, proximal anterior circulation, large vessel occlusion, and smaller core infarcts who have first received thrombolytic therapy. Endovascular therapy with the device should be started within 6 hours of symptom onset. 2. The pRESET® Thrombectomy Device is indicated to restore blood flow by removing thrombus from a large intracranial vessel in patients experiencing stroke within 8 hours of symptom onset. Patients who are ineligible for thrombolytic therapy or who fail thrombolytic therapy are candidates for treatment.

Device Story

Mechanical thrombectomy device for acute ischemic stroke; restores blood flow by removing thrombus from large intracranial vessels (ICA, MCA, BA). Device consists of nitinol retrieval structure, stainless steel push-wire, and radiopaque platinum/iridium markers. Operated by physicians in clinical/interventional settings; deployed via microcatheter to target occlusion site. Device captures thrombus; physician retracts device into microcatheter to remove clot. Output is restored vessel patency (eTICI score). Benefits include reduced disability (mRS score) and improved clinical outcomes. Single-use, sterile, ethylene oxide sterilized.

Clinical Evidence

Prospective, multicenter, randomized controlled trial (PROST, IDE G190099) compared pRESET (n=173) to Solitaire (n=167). Primary endpoints: 90-day mRS ≤2 (pRESET 54.91% vs. Solitaire 57.49%, difference -2.57%) and 24-hour sICH (pRESET 0% vs. Solitaire 1.20%). Secondary endpoint: eTICI ≥2b50 flow (pRESET 84.39% vs. Solitaire 89.22%). Results demonstrated non-inferiority for safety and effectiveness. Animal study (swine model) confirmed comparable safety and performance.

Technological Characteristics

Retrieval structure: Nitinol; Push-wire: Stainless steel; Marker coils: Platinum/Iridium; Shrink tubing: PTFE; Introducer sheath: HDPE. Principle: Mechanical thrombus retrieval. Dimensions: 4x20mm, 5x40mm, 6x30mm. Sterilization: Ethylene Oxide. Connectivity: None (mechanical).

Indications for Use

Indicated for adult patients (≥18 years) with acute ischemic stroke due to persistent, proximal anterior circulation, large vessel occlusion, and smaller core infarcts. Candidates include those who have received thrombolytic therapy (within 6 hours of onset) or those ineligible for/failed thrombolytic therapy (within 8 hours of onset). Contraindications include pregnancy, hypersensitivity to nickel/titanium, severe renal failure, or imaging evidence of hemorrhage, vasculitis, or carotid dissection.

Regulatory Classification

Identification

A neurovascular mechanical thrombectomy device for acute ischemic stroke treatment is a prescription device used in the treatment of acute ischemic stroke to improve clinical outcomes. The device is delivered into the neurovasculature with an endovascular approach, mechanically removes thrombus from the body, and restores blood flow in the neurovasculature.

Special Controls

In combination with the general controls of the FD&C Act, the Neurovascular Mechanical Thrombectomy Device for Acute Ischemic Stroke Treatment is subject to the following special controls:

*Classification.* Class II (special controls). The special controls for this device are:(1) The patient contacting components of the device must be demonstrated to be biocompatible. (2) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use, including: (i) Mechanical testing to demonstrate the device can withstand anticipated tensile, torsional, and compressive forces. (ii) Mechanical testing to evaluate the radial forces exerted by the device. (iii) Non-clinical testing to verify the dimensions of the device. (iv) Non-clinical testing must demonstrate the device can be delivered to the target location in the neurovasculature and retrieve simulated thrombus under simulated use conditions. (v) Non-clinical testing must demonstrate the device is radiopaque and can be visualized. (vi) Non-clinical testing must evaluate the coating integrity and particulates under simulated use conditions. (vii) Animal testing must evaluate the safety of the device, including damage to the vessels or tissue under anticipated use conditions. (3) Performance data must support the sterility and pyrogenicity of the patient contacting components of the device. (4) Performance data must support the shelf-life of the device by demonstrating continued sterility, package integrity, and device functionality over the specified shelf-life. (5) Clinical performance testing of the device must demonstrate the device performs as intended for use in the treatment of acute ischemic stroke and must capture any adverse events associated with the device and procedure. (6) The labeling must include: (i) Information on the specific patient population for which the device is intended for use in the treatment of acute ischemic stroke, including but not limited to, specifying time from symptom onset, vessels or location of the neurovasculature that can be accessed for treatment, and limitations on core infarct size. (ii) Detailed instructions on proper device preparation and use for thrombus retrieval from the neurovasculature. (iii) A summary of the clinical testing results, including a detailed summary of the device- and procedure-related complications and adverse events. (iv) A shelf life.

Predicate Devices

• Solitaire™ 2 Revascularization Device (K162539)

Submission Summary (Full Text)

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January 20, 2023

Image /page/0/Picture/1 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

phenox Limited Catriona Lynch Regulatory Affairs Specialist Kamrick Court, Ballybrit Business Park. Galway H91 XY38, Ireland

Re: K222848

Trade/Device Name: pRESET Thrombectomy Device Regulation Number: 21 CFR 882.5600 Regulation Name: Neurovascular Mechanical Thrombectomy Device for Acute Ischemic Stroke Treatment Regulatory Class: Class II Product Code: POL, NRY Dated: December 16, 2022 Received: December 19, 2022

Dear Catriona Lynch:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal

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statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

# Naira Muradyan -S

Naira Muradyan, Ph.D. Assistant Director DHT5A: Division of Neurosurgical, Neurointerventional and Neurodiagnostic Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

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# Indications for Use

510(k) Number (if known) K222848

Device Name pRESET Thrombectomy Device

#### Indications for Use (Describe)

1. The pRESET® Thrombectomy Device is indicated for use to restore blood flow in the neurovasculature by removing thrombus for the treatment of acute ischemic stroke to reduce disability in patients with a persistent, proximal anterior circulation, large vessel occlusion, and smaller core infarcts who have first received thrombolytic therapy. Endovascular therapy with the device should be started within 6 hours of symptom onset.

2. The pRESET® Thrombectomy Device is indicated to restore blood flow by removing thrombus from a large intracranial vessel in patients experience stroke within 8 hours of symptom onset. Patients who are ineligible for thrombolytic therapy or who fail thrombolytic therapy are candidates for treatment.

Type of Use (*Select one or both, as applicable*)X Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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# 510(k) Summary (21 CFR 807.92)

# K222848

#### I. SUBMITTER

phenox Limited, Kamrick Court Ballybrit Business Park, Galway, Ireland, H91 XY38.

| Primary Correspondent Name: | Catriona Lynch |
|-------------------------------|-------------------------------|
| Title: | Regulatory Affairs Specialist |
| Phone: | [phone] |
| Email: | [e-mail] |
| Secondary Correspondent Name: | Gary Brogan |
| Title: | Managing Director |

Date Prepared: 20 January 2023

#### II. DEVICE

Phone:

Email:

Device Trade Name: pRESET® Thrombectomy Device Common or Usual Name: Neurovascular Mechanical Thrombectomy Device for Acute Ischemic Stroke Treatment; Catheter, Thrombus Retriever Classification: Class 2 device according to 21 CFR 882.5600; 21 CFR 870.1250 Product Code: POL, NRY Review Panel: Neurology

[phone]

[e-mail]

#### III. PREDICATE DEVICE

Device Name: Solitaire™ 2 Revascularization Device, K162539. 510(k) Submitter: Micro Therapeutics, Inc. d/b/a ev3 Neurovascular

# IV. DEVICE DESCRIPTION

The pRESET® Thrombectomy Device is designed to restore blood flow in the neurovasculature by mechanical removal of thrombus in patients experiencing acute ischemic stroke due to large vessel occlusion with thrombus. The device is designed for use in large vessels of the neurovasculature such as the internal carotid artery (ICA) and the middle cerebral artery (MCA). The device is supplied sterile and intended for single use only.

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Materials of Use: See table below for details of the materials used in the construction of the pRESET® Thrombectomy Device.

| Component | Material |
|---------------------|----------------------|
| Retrieval Structure | Nitinol |
| Push-Wire | Stainless Steel Wire |
| Connector Shell | Nitinol |
| Marker coils | Platinum/Iridium |
| Shrink Tubing | PTFE |
| Introducer Sheath | HDPE |

# V. INDICATIONS FOR USE

Comparison of Indications for Use for the pRESET ®Thrombectomy Device and predicate device Solitaire™ 2 Revascularization Device.

| Parameter | Predicate Device | Subject Device |
|---------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Indications for Use | 1. The Solitaire™ 2 Revascularization<br>Device is indicated for use to restore<br>blood flow in the neurovasculature<br>by removing thrombus for the<br>treatment of acute ischemic stroke<br>to reduce disability in patients with<br>a persistent, proximal anterior<br>circulation, large vessel occlusion,<br>and smaller core infarcts who have<br>first received intravenous tissue<br>plasminogen activator (IV t-PA).<br>Endovascular therapy with the<br>device should be started within 6<br>hours of symptom onset.<br>2. The Solitaire™ Revascularization<br>Device is indicated to restore blood<br>flow by removing thrombus from a<br>large intracranial vessel in patients<br>experiencing ischemic stroke within<br>8 hours of symptom onset. Patients<br>who are ineligible for IV t-PA or who<br>fail IV t-PA therapy are candidates<br>for treatment. | 1. The pRESET® Thrombectomy Device<br>is indicated for use to restore blood<br>flow in the neurovasculature by<br>removing thrombus for the treatment<br>of acute ischemic stroke to reduce<br>disability in patients with a persistent,<br>proximal anterior circulation, large<br>vessel occlusion, and smaller core<br>infarcts who have first received<br>thrombolytic therapy. Endovascular<br>therapy with the device should be<br>started within 6 hours of symptom<br>onset.<br>2. The pRESET® Thrombectomy Device<br>is indicated to restore blood flow by<br>removing thrombus from a large<br>intracranial vessel in patients<br>experiencing ischemic stroke within 8<br>hours of symptom onset. Patients who<br>are ineligible for thrombolytic therapy<br>or who fail thrombolytic therapy are<br>candidates for treatment. |

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# phenox

# Traditional 510(k) pRESET® Thrombectomy Device

# VI.COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

| Parameter | Predicate Device | Subject Device |
|------------------------------|-------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------|
| Trade Name | Solitaire™ 2 Revascularization<br>Device | pRESET® Thrombectomy Device |
| 510(k) number | K162539 | K222848 |
| Product Classification | II | II |
| Classification<br>Regulation | 21 CFR 882.5600,<br>21 CFR 870.1250 | 21 CFR 882.5600,<br>21 CFR 870.1250 |
| Product Code | POL, NRY | POL, NRY |
| Principle of Operation | The device is used in the<br>neurovasculature to restore blood<br>flow for treatment of acute<br>ischemic stroke. | The device is used in the<br>neurovasculature to restore blood flow<br>for treatment of acute ischemic stroke. |
| Device Sizes | 4x15mm<br>4x20mm<br>4x40mm<br>6x20mm<br>6x30mm | 4x20mm<br>5x40mm<br>6x30mm |
| Materials | Retrieval Structure- Nitinol<br>Markers- Platinum/Iridium<br>Push Wire- Nitinol<br>Shrink Tubing- PTFE | Retrieval Structure- Nitinol<br>Markers- Platinum/Iridium<br>Push Wire- Stainless Steel<br>Shrink Tubing- PTFE |
| Use | Sterile, Single Use | Sterile, Single Use |
| Sterilization Method | Ethylene Oxide | Ethylene Oxide |
| Packaging | Stored within dispenser coil,<br>Tyvek pouch and shipping carton | Stored within dispenser coil,<br>Tyvek pouch and shinning carton |

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### VII. PERFORMANCE DATA

### BIOCOMPATIBILITY

Biocompatibility testing was conducted based on International Organization for Standardization (ISO) 10993-1:2018: Biological Evaluation of Medical Devices - Part 1: Evaluation and testing within a risk management process and the US FDA guidance document "Use of International Standard ISO 10993, 'Biological Evaluation of Medical Devices - Part 1: Evaluation and testing within a risk management process" (2020). Results confirmed the pRESET® Thrombectomy Device is biocompatible.

| Biological Effects | Test names | Conclusions | |
|--------------------|-----------------------------------------------------------------|-------------------------------------------|----------------------------|
| Cytotoxicity | ISO MEM elution –<br>L929 fibroblast cultures | Non-cytotoxic | |
| Sensitization | ISO guinea pig maximization test | No sensitization indicated | |
| Skin Irritation | Rabbit<br>primary skin irritation/<br>intracutaneous reactivity | No irritation indicated | |
| | Systemic toxicity | Material mediated pyrogenicity test | Non-pyrogenic |
| | Systemic toxicity | Acute systemic toxicity | No acute systemic toxicity |
| Hemocompatibility | Thromboresistance in dogs | Thromboresistant | |
| | In vitro hemocompatibility<br>Partial thromboplastin time (PTT) | No Hemolysis indicated | |
| | Hemocompatibility | Hemolysis (ASTM method) direct<br>contact | No Hemolysis indicated |
| Hemocompatibility | Hemolysis (ASTM method) indirect<br>extract | | |
| Hemocompatibility | Complement activation | No complement activation | |

Table below summarizes testing performed on the pRESET® Thrombectomy Device.

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### STERILIZATION

pRESET® Thrombectomy Device is sterilized by Ethylene Oxide gas. The sterilization cycle has been validated to ensure a sterility assurance level (SAL) of 10° in accordance with the EN ISO 11135:2014 & A1:2019 and AAMI TIR28:2016.

Aging studies have established the pRESET® Thrombectomy Device packaging remains functional and maintains sterility for up to 3 years. Aging studies for packaging integrity, seal strength and device functionality were performed and met acceptance criteria.

### NON-CLINICAL PERFORMANCE DATA

Non-clinical testing was completed to support the substantial equivalence determination to the predicate. The tests are summarized below.

#### Performance Testing - Bench

The following bench testing was performed to support substantial equivalence.

| Test names | Test Description | Conclusions |
|---------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
| Simulated Use | It shall be possible to safely and reliably prepare, deploy and retract the device in a nominal and worst-case 3D model as described in the instructions for use without damage to the device. | Pass |
| Dimensional Verification | Expanded outer diameter (OD)<br>Retriever device length<br>Working length of retrieval device<br>Effective length of retrieval device<br>System length<br>Diameter 10 mm from device connection point<br>Diameter 275 mm from device connection point<br>Length of uncovered marker<br>Marker position<br>Diameter of heat shrink - device connection point<br>Diameter of distal marker coils<br>Length of distal marker coils | Pass |
| Radial Force | The relative Chronic Outward Force<br>(RCOF) in the labeled vessel diameters<br>must meet acceptance criteria. | Pass |
| Radiopacity | Proximal and distal ends of the retrieval<br>device must be radiopaque. | Pass |
| Kink Resistance | The PRESET device will not kink during<br>simulated use in a nominal and worst-<br>case 3D model following the instructions<br>for use. | Pass |
| | The PRESET stent region does not kink or<br>collapse while passing through a worst-<br>case anatomical model incorporating<br>minimum bend radii. | Pass |
| System Surface Finish | The external surface of the effective<br>length of the device shall appear free<br>from extraneous matter, process and<br>surface defects. | Pass |
| Ar Transition Temperature | Ar transition temperature of the PRESET<br>device will be appropriate for clinical<br>usage. Test will use the bend and free<br>recovery method. | Pass |
| Device Deployment | It shall be possible to safely and reliably<br>deploy the device as described in the<br>instructions for use without damage to<br>the device. | Pass |
| Retraction into the<br>Microcatheter | It shall be possible to advance a<br>representative microcatheter over the<br>deployed device, at the site of<br>deployment, until it is fully contained<br>within the inner lumen of the<br>microcatheter without damage to the<br>device. | Pass |
| Delivery and<br>Resheathing<br>Forces | The maximum delivery and resheathing<br>forces measured during simulated use<br>clinical conditions. | Pass |
| Re-Sheathing | It shall be possible to re-sheath the<br>device, as described in the instructions<br>for use, after it has been prepared<br>deployed and retracted as described in<br>the instructions for use. | Pass |
| Marker Coil Tensile<br>Strength | The minimum tensile strength of the<br>union between the distal marker coils<br>and the stent retriever shall meet the<br>acceptance criteria. | Pass |
| System Tensile Strength | The minimum tensile strength of the<br>thrombectomy system is evaluated<br>to the acceptance criteria. | Pass |
| Torque Strength | The system must not break after 3 full<br>rotations of the insertion wire. | Pass |
| Ancillary Device<br>Compatibility | It shall be possible to safely and reliably<br>prepare, deploy and retract the device in<br>a nominal and worst-case 3D model per<br>the instructions for use without damage<br>to any ancillary devices listed. | Pass |

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# Performance Testing - Animal

A Good Laboratory Practice (GLP) safety study of the pRESET® Thrombectomy Device in a swine model was executed. This study was initiated to assess the safety and performance of the pRESET device in comparison to a control by evaluating worst-case device use (e.g., 3 passes and 6 resheathings of the retrieval device), clot removal, recanalization and device usability performance at both sub-acute (Day 3) and chronic endpoints (Day 30). The control device used for the purpose of the study was the Solitaire™ 2 Revascularization Device. The safety and performance of the pRESET Thrombectomy Device in a swine model of acute vascular occlusion was comparable to the control device.

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# CLINICAL EXPERIENCE

The pRESET® Thrombectomy Device was the subject of a prospective, multicenter, randomized controlled clinical trial (RCT) to demonstrate the safety and effectiveness of the device, and to evaluate these outcomes against the Solitaire™ Revascularization Device. A summary of the trial design is provided in Table 1.

| Title | pRESET for Occlusive Stroke Treatment (PROST) |
|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Trial Phase | Pre-market clearance (IDE G190099) |
| Trial Design | Prospective, multicenter randomized clinical trial |
| Inclusion Criteria | Age $\ge$ 18 years. Clinical signs consistent with acute ischemic stroke. Able to be treated within 8 hours of stroke symptom onset & within 1.5 hours (90 min) from screening CT / MRI to groin puncture. Pre-stroke mRS $\le$ 1. NIHSS $\ge$ 6 at the time of enrollment. If t-PA is indicated, initiation of IV t-PA should be administered as soon as possible and no later than 3 hours of onset of stroke symptoms, with investigator verification that the subject has received/is receiving the correct IV t-PA dose (0.9 mg/kg) for the estimated weight. eTICI $\le$ 1 confirmed by angiography that is accessible to the mechanical thrombectomy device in the following locations: Intracranial internal carotid M1 and/or M2 segment of the MCA Carotid terminus Vertebral artery Basilar artery NOTE: M1 segment of the MCA is defined as the arterial trunk from its origin at the ICA to the first bifurcation or trifurcation into major branches neglecting the small temporal-polar branch. ASPECTS score must be 6-10 on NCCT or DWI-MRI. If automated core volume assessment software is used: MR diffusion-weighted imaging (DWI) $\le$ 50 cc Computed tomography perfusion (CTP) core $\le$ 50 cc Subject is willing to conduct protocol-required follow-up visits. A valid signed and dated informed consent by participant or LAR (legally authorized representative) has been obtained. |

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| Exclusion Criteria | • Received IA t-PA prior to enrollment in the study.<br>• Female who is pregnant or lactating or has a positive pregnancy test at time of admission.<br>• Rapid neurological improvement prior to study enrollment suggesting resolution of signs/symptoms of stroke.<br>• Known serious sensitivity to radiographic contrast agents.<br>• Known sensitivity to nickel, titanium metals, or their alloys.<br>• Enrolled in other investigational studies that would interfere with study endpoints.<br>• Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency.<br>• Known renal failure as defined by a serum creatinine > 2.0 mg/dl (or 176.8 µmol/l) or glomerular filtration rate (GFR) < 30.<br>• Requires hemodialysis or peritoneal dialysis, or has a contraindication to an angiogram.<br>• Life expectancy of less than 90 days.<br>• Clinical presentation suggests a subarachnoid hemorrhage, even if initial CT or MRI scan is normal.<br>• Suspicion of aortic dissection.<br>• Comorbid disease or condition that would confound the neurological and functional evaluations or compromise survival or ability to complete follow-up assessments.<br>• Known to currently use or has a recent history of illicit drug(s) or abuses alcohol (defined as regular or daily consumption of more than four alcoholic drinks per day).<br>• Known arterial condition (e.g., proximal vessel stenosis or pre-existing stent) that would prevent the device from reaching the target vessel and/or preclude safe recovery of the device.<br>• Requires balloon angioplasty or stenting of the carotid artery at the time of the index procedure.<br>• Angiographic evidence of carotid dissection. |
|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| IMAGING: | • CT or MRI evidence of hemorrhage on presentation.<br>• CT or MRI evidence of mass effect or intra-cranial tumor (except small meningioma).<br>• CT or MRI evidence of cerebral vasculitis.<br>• CT or MRI-DWI showing ASPECTS 0-5. Alternatively, if automated core volume assessment software is used, MRI-DWI or CTP core > 50 cc.<br>• CT or MRI shows evidence of carotid dissection or complete cervical carotid occlusion requiring a stent.<br>• Any imaging evidence that suggests, in the opinion of the investigator, the subject is not appropriate for mechanical thrombectomy intervention (e.g., inability to navigate to target lesion, moderate/large infarct with poor collateral circulation, etc.).<br>• Occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation) as confirmed by angiography, or clinical evidence of bilateral strokes or strokes in multiple territories. |

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| Randomization | 1:1 using stratification factors:<br>• Age: ≥ 65 and < 65<br>• Site of occlusion: ICA, MCA and BA<br>• Baseline/Enrollment NIHSS score: < 17 and ≥ 17<br>• Prior IV t-PA usage: Yes and No<br>• Time to symptom onset: ≥ 4 hours and < 4 hours |
|---------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Sample Size | • Intent-to-Treat Population: 340 subjects: 173 pRESET & 167 Solitaire<br>• Per Protocol Population: 266 subjects: 138 pRESET & 128 Solitaire<br>• As Treated Population: 322 subjects: 166 pRESET & 156 Solitaire |
| Follow-Up | 24 hours, 7 Days, 30 Days & 90 Days |
| Primary Endpoints | • Proportion of subjects with mRS ≤ 2 at 90 days after the index procedure<br>• Proportion of subjects with device- or procedure-related symptomatic<br>intracerebral hemorrhage (sICH) within 24 hours (-8/+12 hrs) of the index<br>procedure |
| Secondary Endpoints | • Proportion of subjects with eTICI 2b50 or greater flow in the target vessel<br>post-procedure with ≤ 3 passes of the assigned study device<br>• Proportion of subjects with eTICI 2c or greater following the first pass of the<br>assigned study device<br>• Overall mortality at 90 days following the index stroke<br>• Distribution of mRS shift at 90 days across the entire spectrum of |

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# enox

# Traditional 510(k) pRESET® Thrombectomy Device

A total of 340 subjects were enrolled and randomized into PROST at 24 sites across the US (n=19) and Germany (n=5): 173 in the pRESET® arm and 167 in the Solitaire arm. Key subject baseline demographics were similar across the two arms (Table 2).

| Table 2: Key Baseline Demographics | | | |
|------------------------------------|---------------------|-------------------|----------------------|
| Parameter | Enrolled<br>(N=340) | pRESET<br>(N=173) | Solitaire<br>(N=167) |
| Age (years) | | | |
| N | 340 | 173 | 167 |
| Median (Min, Max) | 73.0 (29, 96) | 73.0 (29, 96) | 75.0 (31, 96) |
| Gender | | | |
| N | 340 | 173 | 167 |
| Male | 170 (50.0%) | 90 (52.0%) | 80 (47.9%) |
| Female | 170 (50.0%) | 83 (48%) | 87 (52.1%) |
| NIHSS at Admission | | | |
| N | 339 | 173 | 166 |
| Median (Min, Max) | 16.0 (6, 31) | 16.0 (6, 29) | 16.0 (6, 31) |
| mRS before Stroke | | | |
| 0 | 251 (73.8%) | 130 (75.1%) | 121 (72.5%) |
| 1 | 84 (24.7%) | 41 (23.7%) | 43 (25.7%) |
| 2 | 3 (0.9%) | 1 (0.6%) | 2 (1.2%) |
| Not Reported | 2 (0.6%) | 1 (0.6%) | 1 (0.6%) |
| ASPECTS Score | | | |
| N | 336 | 171 | 165 |
| Median (Min, Max) | 9.0 (6, 10) | 9.0 (6, 10) | 9.0 (6, 10) |
| Core Infarct Size (cc) | | | |
| N | 117 | 60 | 57 |
| Median (Min, Max) | 10.0 (0, 85) | 6.5 (0, 66) | 14.0 (0, 85) |
| Target Occlusion Location | | | |
| Left Hemisphere | 146 (42.9%) | 78 (45.1%) | 68 (40.7%) |
| Right Hemisphere | 161 (47.4%) | 81 (46.8%) | 80 (47.9%) |
| Posterior | 17 (5.0%) | 9 (5.2%) | 8 (4.8%) |
| Not Reported | 16 (4.7%) | 5 (2.9%) | 11 (6.6%) |

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The Intent-to-Treat (ITT) population (n=340) included all subjects who had a signed informed consent form (ICF) and were randomized.

The Per Protocol (PP) population (n=266) included all subjects who underwent treatment with a study device, met the eligibility criteria and had primary effectiveness outcome data.

The As Treated (AT) population (n=322) included all subjects who underwent treatment with a study device, irrespective of device assignment. There were 0 treatment crossovers.

| Table 3: Final Subject Disposition | | | |
|------------------------------------|---------------------|-------------------|----------------------|
| Parameter | Enrolled<br>(N=340) | pRESET<br>(N=173) | Solitaire<br>(N=167) |
| Randomized | 340 (100.0%) | 173 (100.0%) | 167 (100.0%) |
| Underwent Study Procedure1 | 322 (94.7%) | 166 (96.0%) | 156 (93.4%) |
| Completed Follow-Up | | | |
| 24 hour | 322 (94.7%) | 166 (96.0%) | 156 (93.4%) |
| Day 7 | 296 (87.1%) | 152 (87.9%) | 144 (86.2%) |
| Day 30 | 283 (83.2%) | 144 (83.2%) | 139 (83.2%) |
| Day 902 | 265 (77.9%) | 137 (79.2%) | 128 (76.6%) |
| Discontinued from the Study3 | | | |
| Death | 47 (13.8%) | 24 (13.9%) | 23 (13.8%) |
| Withdrawn | 24 (7.1%) | 10 (5.8%) | 14 (8.4%) |
| Lost to Follow-Up | 2 (0.5%) | 0 (0.0%) | 2 (1.2%) |

1 Following randomization, 18 subjects did not undergo study Procedure for the following reasons: clot migrated, resolved, or could not be reached, the subject did not meet all eligibility criteria (including absence of a subarachnoid hemorrhage), the study device was not used, or a wire perforation occurred.

² The total number of subjects who completed Day 90 follow-up (n=265) differs from the total number of subjects in the PP population (n= 266) as these two populations are not composed of the same subjects who died prior to Day 90 are excluded from Completed Follow-Up Day 90 but may be included in the PP population as a primary effectiveness outcome data point is available i.e., mRS = 6. Subjects who attended Day 90 follow-up are included in the Completed Follow-Up Day 90 but may be excluded from the PP population as they had a deviation against the eligibility criteria.

3 Two subjects did not attend the Day 90 follow-up visit; however, these patients remained active in the study at 90 days postprocedure and were confirmed to be alive at Day 90.

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Image /page/15/Picture/0 description: The image shows the word "phenox" in a sans-serif font. The word is written in a dark blue color. The letters are all lowercase and connected to each other. The image is simple and clean, with no other elements present.

The pRESET® Thrombectomy Device was demonstrated to be non-inferior to the Solitaire™ Revascularization Device in the restoration of blood flow in the neurovasculature (eTICI ≥ 2b50) and for the treatment of acute ischemic stroke to reduce disability in patients (mRS ≤ 2 at 90 days) (Table 4). This can be achieved with a similar safety profile to the Solitaire™ Revascularization Device, with the pRESET® Thrombectomy Device demonstrated to be noninferior in the occurrence of device- or procedure-related symptomatic intracerebral hemorrhage (sICH) within 24 hours of the index procedure (Table 4).

#### Table 4: Key Outcome Measures (Intent-to-Treat Population)

Primary Effectiveness Endpoint After 90 days following the procedure, is the lower bound of the 1-sided 95% confidence interval of the difference (pRSST minus Solitaire) in global disability (mRS ≤ 2) above the a priori threshold of -12.5%?

| | Total Subjects | 90 Day mRS ≤2<br>n (%) | Confidence Interval<br>(Lower Bound, Upper Bound) |
|------------------------|----------------|------------------------|---------------------------------------------------|
| pRESET | 173 | 95 (54.91%) | |
| Solitaire | 167 | 96 (57.49%) | |
| pRESET minus Solitaire | | -2.57% | -11.42%, 6.28% |

#### Primary Safety Endpoint

Within 24 hours (-8/+12 hours) after the study procedure, is the upper bound of the 1-sided 95% confidence interval of the difference (pRESET minus Solitaire) with device-related sICH below the a priori threshold of 5%?

| | Total Subjects | 24 Hour sICH n (%) | Confidence Interval<br>(Lower Bound, Upper Bound) |
|------------------------|----------------|--------------------|---------------------------------------------------|
| pRESET | 173 | 0 (0.00%) | . |
| Solitaire | 167 | 2 (1.20%) | . |
| pRESET minus Solitaire | . | -1.20% | -2.58%, 0.19% |

#### Secondary Effectiveness Endpoint

Following a maximum of 3 passes of the assigned study device, and based on the best eTICI result within ≤ 3 passes, is the lower bound of the 1-sided 95% confidence interval of the difference (pRESET minus Solitaire) in the proportion of patients with eTlCl 2b50 or greater flow in the target vessel post-procedure above the a priori threshold of -12.1%?

| | Total Subjects | eTICI ≥ 2b50 n (%) | Confidence Interval<br>(Lower Bound, Upper Bound) |
|------------------------|----------------|--------------------|---------------------------------------------------|
| pRESET | 173 | 146 (84.39%) | . |
| Solitaire | 167 | 149 (89.22%) | . |
| pRESET minus Solitaire | . | -4.83% | -10.84%, 1.19% |

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When any additional device usage or more than three passes of the study device are considered failures, regardless of whether the study device alone achieved eTICI ≥ 2b50 before additional passes were attempted or needed the use of an additional device, the performance of the pRESET® Thrombectomy Device and the Solitaire™ Revascularization Device are listed below for all study populations (Table 5).

| Table 5: Key Outcome Measures with Additional Device Use and > 3 Passes as Failures | | | |
|-------------------------------------------------------------------------------------|-----------------------------------|----------------------------------|----------------------------------|
| Parameter | ITT Population<br>Success n/N (%) | PP Population<br>Success n/N (%) | AT Population<br>Success n/N (%) |
| 90 Day mRS ≤2 | | | |
| pRESET | 74/173 (42.77%) | 67/138 (48.55%) | 71/166 (42.77%) |
| Solitaire | 68/167 (40.72%) | 60/128 (46.88%) | 68/156 (43.59%) |
| pRESET minus Solitaire | 2.06% | 1.68% | -0.82% |
| Confidence Interval (Lower, Upper Bound) | -6.74%, 10.85% | -8.40%, 11.76% | -9.90, 8.27% |
| eTICI ≥ 2b50 | | | |
| pRESET | 124/173 (71.68%) | 105/138 (76.09%) | 121/166 (72.89%) |
| Solitaire | 128/167 (76.65%) | 98/128 (76.56%) | 118/156 (75.64%) |
| pRESET minus Solitaire | -4.97% | -0.48% | -2.75% |
| Confidence Interval (Lower, Upper Bound) | -12.76%, 2.82% | -9.05%, 8.10% | -10.76, 5.26% |

In total, 231 (67.9%) subjects had at least one adverse event with 105 (30.9%) subjects having a serious adverse event.

There was no difference in the number of adverse events (p-value: 0.7340) or serious adverse events (p-value: 0.7117) between the two arms.

The number of subjects who had a device- or procedure-related serious adverse event also did not differ across the arms (p-value: 0.7663).

| Parameter | ITT Population<br>(N=340) | pRESET<br>(N=173) | Solitaire<br>(N=167) | P-Value[1] |
|-------------------------------------|---------------------------|-------------------|----------------------|------------|
| Adverse Event (AE) | | | | |
| Number Subjects (%) | 231 (67.9%) | 119 (68.8%) | 112 (67.1%) | . |
| 95% Exact Confidence Interval | . | (61.3%, 75.6%) | (59.4%, 74.1%) | 0.7340 |
| Serious Adverse Event (SAE) | | | | |
| Number Subjects (%) | 105 (30.9%) | 55 (31.8%) | 50 (29.9%) | . |
| 95% Exact Confidence Interval | . | (24.9%, 39.3%) | (23.1%, 37.5%) | 0.7117 |
| Procedure and/or Device Related SAE | | | | |
| Number Subjects (%) | 28 (8.2%) | 15 (8.7%) | 13 (7.8%) | . |
| 95% Exact Confidence Interval | . | (4.9%, 13.9%) | (4.2%, 12.9%) | 0.7663 |

1P-Value obtained from a generalized linear model with the randomized treatment as the dependent variable

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# phenox

# Traditional 510(k) pRESET® Thrombectomy Device

The majority of device- or procedure-related serious adverse events were classed as Nervous System Disorders (Table 7).

| | Table 7: Device- or Procedure-Related Serious Adverse Events | | |
|-----------------------------------------------|--------------------------------------------------------------|-------------------|----------------------|
| System Organ Class<br>Preferred Term | ITT Population<br>(N=340) | pRESET<br>(N=173) | Solitaire<br>(N=167) |
| Cardiac Disorders | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Acute Myocardial Infarction | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Gastrointestinal Disorders | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Vomiting | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Infections & Infestations | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Pneumonia | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Injury, Poisoning & Procedural Complications | 5 (1.5%) | 4 (2.3%) | 1 (0.6%) |
| Post Procedural Stroke | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Vascular Access Site Complication | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Vascular Pseudoaneurysm | 2 (0.6%) | 1 (0.6%) | 1 (0.6%) |
| Vasoplegia Syndrome | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Nervous System Disorders | 21 (6.2%) | 9 (5.2%) | 12 (7.2%) |
| Basal Ganglia Hematoma | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Brain Edema | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Cerebral Artery Embolism | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Cerebral Artery Occlusion | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Cerebral Hemorrhage | 2 (0.6%) | 1 (0.6%) | 1 (0.6%) |
| Cerebral Infarction | 2 (0.6%) | 0 (0.0%) | 2 (1.2%) |
| Cerebral Reperfusion Injury | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Cerebrovascular Accident | 3 (0.9%) | 2 (1.2%) | 1 (0.6%) |
| Hemorrhage Intracranial | 3 (0.9%) | 1 (0.6%) | 2 (1.2%) |
| Hemorrhagic Transformation Stroke | 2 (0.6%) | 1 (0.6%) | 1 (0.6%) |
| Hydrocephalus | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Intracranial Mass | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Stroke In Evolution | 2 (0.6%) | 1 (0.6%) | 1 (0.6%) |
| Subarachnoid Hemorrhage | 3 (0.9%) | 1 (0.6%) | 2 (1.2%) |
| Vertebral Artery Dissection | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |
| Respiratory, Thoracic & Mediastinal Disorders | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Respiratory Failure | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Vascular Disorders | 2 (0.6%) | 1 (0.6%) | 1 (0.6%) |
| Peripheral Ischemia | 1 (0.3%) | 0 (0.0%) | 1 (0.6%) |
| Vascular Dissection | 1 (0.3%) | 1 (0.6%) | 0 (0.0%) |

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### VIII. CONCLUSIONS

phenox Ltd. have demonstrated that the pRESET® Thrombectomy Device is substantially equivalent to the Solitaire™ 2 Revascularization Device (K162539) through a multicenter, prospectively designed, randomized controlled trial. The randomized trial design minimizes the uncertainty and bias of the trial results by allowing the discrimination of patient outcomes that are caused by the pRESET Thrombectomy Device from outcomes that may be caused by other factors. pRESET® Thrombectomy Device has the same intended use, similar technological characteristics, similar materials and the same operating principle as the predicate device. Substantial equivalence is demonstrated through bench, animal and clinical testing.