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CONFIDENTIAL — PRE-SUBMISSION CORRESPONDENCE

SOLSTICE BIOMEDICAL INC. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 Tel: (617) 482-9100

Fax: (617) 482-9101

www.solsticebiomedical.com

June 2, 2025

Director, Division of Chemistry and Toxicology Devices Office of Health Technology 2 (OHT2) Center for Devices and Radiological Health (CDRH) U.S. Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993

Re: Pre-Submission (Q-Submission) Meeting Request — Solstice Lumina™ Continuous Glucose Monitoring System (Lumina C14 Implantable Sensor and Lumina R7 Wearable Reader/Transmitter)

Anticipated Product Code: QKQ Anticipated Regulation Number: 21 C.F.R. § 862.1355 Anticipated Device Classification: Class II

Dear Director and Members of the Division:

Solstice Biomedical Inc. ("Solstice" or "SBI"), a Delaware corporation (File No. 7834291), respectfully requests a Pre-Submission (Q-Submission) meeting with the Division of Chemistry and Toxicology Devices, Office of Health Technology 2, Center for Devices and Radiological Health ("CDRH"), in accordance with the guidance set forth in the FDA's Requests for Feedback and Meetings for Medical Device Submissions: The Q-Submission Program (Revised January 2023). The purpose of this request is to discuss the planned traditional 510(k) premarket notification submission for the Solstice Lumina™ Continuous Glucose Monitoring System (the "Lumina CGM System" or the "System"), comprising the Lumina C14 subcutaneously implantable continuous glucose monitoring sensor (the "C14 Sensor") and the Lumina R7 wearable reader/transmitter (the "R7 Reader").

SBI is the wholly-owned U.S. subsidiary of Solstice Biomedical Devices Ltd., a private limited company incorporated in Ireland (Companies Registration Office No. 648231), headquartered at Unit 14, Liffey Innovation Park, Chapelizod, Dublin D20 FX72, Ireland. SBI will serve as the intended 510(k) holder and U.S. agent for the Lumina CGM System and has been authorized by Solstice Biomedical Devices Ltd. to engage with the Agency on all regulatory matters related to U.S. market entry of the System. SBI has retained Calderwood & Harkness LLP as outside regulatory and legal counsel for this submission, and Pinnacle Regulatory Consulting Group LLC as its regulatory consulting partner, as further described below.

We submit this cover letter in advance of the complete Pre-Submission meeting package, which Solstice will submit no later than June 16, 2025, in conformance with the 60-calendar-day advance requirement for Pre-Submission meeting requests. The following sections provide sponsor information, a device description summary, the intended regulatory pathway, predicate device identification, topics and questions proposed for discussion, and administrative details necessary for the Agency's scheduling and review.

1. Sponsor Information

The sponsor and intended 510(k) holder for the Lumina CGM System is:

Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 United States Tel: (617) 482-9100

Fax: (617) 482-9101

The following individuals are designated as principal contacts for this Pre-Submission request and all related regulatory correspondence:

Primary Contact for Correspondence:

Marcus Hale Vice President, U.S. Operations Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 Tel: (617) 482-9115

Email: m.hale@solsticebiomedical.com

Regulatory Affairs Contact:

Dr. Niamh Tierney, RAC Vice President, Regulatory Affairs Solstice Biomedical Devices Ltd. Unit 14, Liffey Innovation Park Chapelizod, Dublin D20 FX72, Ireland Tel: +353 1 697-4200

Email: n.tierney@solsticebiomedical.ie

Legal Counsel (Authorized Representative):

Miriam Calloway, Esq. Partner, Healthcare & Life Sciences Regulatory Practice Calderwood & Harkness LLP 1401 K Street NW, Suite 900 Washington, D.C. 20005 Tel: (202) 654-8800

Email: m.calloway@calderwoodharkness.com

Ms. Calloway previously served as Senior Counsel, Office of the Chief Counsel, Center for Devices and Radiological Health, U.S. Food and Drug Administration (2011–2017), and is intimately familiar with the Division's review processes and the regulatory landscape governing in vitro diagnostic and continuous glucose monitoring devices.

Additional Counsel:

Amy Whitfield, Esq. Lead Associate, Healthcare & Life Sciences Regulatory Practice Calderwood & Harkness LLP 1401 K Street NW, Suite 900 Washington, D.C. 20005 Tel: (202) 654-8824

Email: a.whitfield@calderwoodharkness.com

Regulatory Consultant:

Pinnacle Regulatory Consulting Group LLC 9500 Medical Center Drive, Suite 210 Rockville, MD 20850 Tel: (301) 741-3200

Contacts:

• Dr. Sandra Ellison, Managing Director

Email: s.ellison@pinnaclereg.com

• Thomas Greenbaum, Senior Regulatory Specialist

Email: t.greenbaum@pinnaclereg.com

Dr. Ellison previously served as a scientific reviewer in the Division of Chemistry and Toxicology Devices, CDRH, and brings substantial expertise in the review and clearance of continuous glucose monitoring and electrochemical biosensor devices.

2. Device Description Summary

2.1 Product Line Overview

The Solstice Lumina™ CGM System is a next-generation, continuous glucose monitoring system designed to provide real-time, minimally invasive interstitial glucose measurement for the management of diabetes mellitus. The System is comprised of two hardware components — the Lumina C14 Sensor and the Lumina R7 Reader — together with supporting firmware, software, and a mobile application. Solstice intends to submit a single, integrated 510(k) premarket notification covering both the C14 Sensor and the R7 Reader as a unified system, as the components are designed, verified, and validated to function together and are not independently marketed or used.

2.2 Device Variant 1 — Lumina C14 Sensor

The Lumina C14 is a subcutaneously implantable, continuous glucose monitoring sensor with a maximum approved wear duration of fourteen (14) days (336 hours). The C14 Sensor employs a fourth-generation enzymatic electrochemical biosensor architecture utilizing Solstice's proprietary platinum-iridium electrode coating technology, designated internally as PtIr-4G. The PtIr-4G coating is engineered to enhance signal stability, reduce oxygen dependency, and extend sensor longevity over the full 14-day wear period.

Key technical specifications of the C14 Sensor include:

• Sensing Mechanism: Fourth-generation enzymatic electrochemical biosensor (glucose oxidase-based) with PtIr-4G platinum-iridium electrode coating

• Wear Duration: 14 days (336 hours), single-use, disposable

• Implantation Site: Subcutaneous tissue, posterior upper arm (recommended) or abdomen (alternate)

• Insertion Method: Single-use, spring-loaded applicator (Lumina C14 Applicator, included in sensor kit)

• Measurement Range: 40–400 mg/dL

• Data Sampling Rate: Every 60 seconds (1-minute intervals); averaged and transmitted every 5 minutes

• Warm-Up Time: ≤ 60 minutes from insertion to first glucose reading

• Wireless Communication: Bluetooth Low Energy (BLE) 5.2 protocol for one-way data transmission from the C14 Sensor to the R7 Reader

• Power Source: Integrated silver oxide micro-battery (non-rechargeable, non-replaceable)

• Biocompatible Materials: Medical-grade silicone housing, parylene-C conformal coating, platinum-iridium electrode, biocompatible adhesive patch (cyanoacrylate-free)

• Sterilization: Ethylene oxide (EtO) sterilization; supplied sterile in sealed, single-use packaging

• Embedded Firmware: Lumina Firmware v3.4.2

2.3 Device Variant 2 — Lumina R7 Reader

The Lumina R7 is a wearable reader and transmitter device designed to be worn on the posterior upper arm, in proximity to the C14 Sensor. The R7 Reader receives BLE data from the C14 Sensor, processes the glucose signal using Solstice's proprietary glucose prediction algorithm (LuminaPredict Algorithm v2.1), and displays real-time glucose values, trend arrows, and 8-hour trend graphs on an integrated 1.4-inch AMOLED touchscreen display. The R7 Reader also transmits processed glucose data via BLE to the Solstice Lumina™ mobile application installed on the user's personal smartphone (iOS and Android platforms supported).

Key technical specifications of the R7 Reader include:

• Display: 1.4-inch AMOLED capacitive touchscreen, 320 × 320 pixel resolution

• Data Reception: BLE 5.2 receiver; receives raw sensor data from C14 Sensor at 5-minute intervals

• Data Processing: Onboard processing of glucose signal using LuminaPredict Algorithm v2.1 for noise filtration, trend calculation, and predictive glucose estimation

• Displayed Information: Real-time glucose value (mg/dL), directional trend arrows (rapidly falling, falling, stable, rising, rapidly rising), 8-hour trend graph, time-in-range statistics

• Alert Functionality: Configurable hypoglycemia alerts (default: ≤ 55 mg/dL), configurable hyperglycemia alerts (default: ≥ 250 mg/dL), rate-of-change alerts, signal loss alerts; audible, vibratory, and visual alert modalities

• Alert Latency: ≤ 5 minutes from sensor measurement to alert notification

• Mobile Application Communication: BLE 5.2 transmission to Solstice Lumina™ Mobile App v1.0.3 (compatible with iOS 16.0+ and Android 13.0+)

• Data Storage: 90-day onboard glucose data storage; cloud backup via mobile application (optional, user-enabled)

• Power Source: Rechargeable lithium polymer battery; battery life ≥ 14 days per full charge; USB-C charging

• Water Resistance: IP67 rated (immersion to 1 meter for 30 minutes)

• Wearability: Medical-grade silicone band with hypoallergenic adhesive patch; designed for continuous 14-day wear concurrent with C14 Sensor wear period

• Operating System: Lumina Reader OS v2.1.0 (proprietary real-time embedded operating system)

2.4 Software Components

The Lumina CGM System incorporates the following software and firmware components, each of which will be documented in accordance with FDA guidance on the content of premarket submissions for software contained in medical devices and the FDA's premarket cybersecurity guidance:

1. Lumina Firmware v3.4.2 — Embedded firmware on the C14 Sensor controlling electrochemical measurement acquisition, analog-to-digital conversion, signal conditioning, and BLE data transmission.

2. Lumina Reader OS v2.1.0 — Proprietary real-time embedded operating system on the R7 Reader managing BLE data reception, algorithm execution, display rendering, alert management, and mobile application pairing.

3. LuminaPredict Algorithm v2.1 — Proprietary glucose prediction and trend analysis algorithm executing on the R7 Reader. LuminaPredict employs an adaptive Kalman filter and machine learning-based signal processing to convert raw sensor current (nanoamperes) to calibrated glucose concentration (mg/dL) and to generate trend predictions and rate-of-change calculations.

4. Lumina Mobile App v1.0.3 — Companion mobile application for iOS (16.0+) and Android (13.0+) platforms providing extended data visualization, glucose data sharing with healthcare providers, retrospective analysis, and optional cloud data backup. The mobile application is intended to complement — not replace — the R7 Reader display, and the System is designed to function fully without the mobile application.

2.5 Intended Use

The Solstice Lumina™ CGM System is intended for prescription use for the continuous monitoring of interstitial fluid glucose levels in persons aged 18 years and older with Type 1 or Type 2 diabetes mellitus. The System is intended to replace fingerstick blood glucose testing for diabetes treatment decisions, including insulin dosing, when used in conjunction with a compatible blood glucose meter for calibration verification. The System is not intended for use in persons under the age of 18, in pregnant women, in critically ill patients, or as a sole basis for making therapy adjustments without clinical judgment.

3. Intended Regulatory Pathway

Solstice intends to submit a traditional 510(k) premarket notification for the Lumina CGM System in accordance with Section 510(k) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 360(k)) and the implementing regulations at 21 C.F.R. Part 807, Subpart E. The Lumina CGM System will be submitted as a single, integrated device system encompassing both the C14 Sensor and the R7 Reader.

The anticipated regulatory classification parameters are as follows:

• Product Code: QKQ (Electrode, Glucose, Subcutaneous)

• Regulation Number: 21 C.F.R. § 862.1355 (Glucose test system)

• Device Classification: Class II (with special controls)

Solstice notes that the classification of continuous glucose monitoring systems under product code QKQ and 21 C.F.R. § 862.1355 reflects the FDA's reclassification order that became effective in March 2024, which reclassified integrated continuous glucose monitoring systems from Class III (PMA) to Class II (510(k)) with special controls, provided that such devices meet the performance criteria and special controls identified in the reclassification order.

In addition to the traditional 510(k) pathway, Solstice also intends to explore during the Pre-Submission meeting whether the Lumina CGM System qualifies for integrated continuous glucose monitoring (iCGM) classification under the applicable special controls. Solstice believes that the System's performance characteristics — including its measurement accuracy, alert functionality, and sensor longevity — may support an iCGM classification determination, and Solstice seeks the Division's preliminary feedback on the criteria and evidentiary standards applicable to an iCGM classification for the Lumina CGM System. Solstice acknowledges that iCGM classification carries specific performance requirements and special controls, and Solstice is prepared to discuss how the Lumina CGM System's design and performance data align with those requirements.

4. Predicate Device Identification

4.1 Primary Predicate Device

Solstice has identified the following device as the primary predicate for the Lumina CGM System's 510(k) substantial equivalence determination:

NovaSense Medical Technologies Inc. GlucoTrack NX-500 CGM System

• 510(k) Number: K211034

• Date of Clearance: June 18, 2022

• Product Code: QKQ

• Classification: Class II

• Regulation Number: 21 C.F.R. § 862.1355

• Key Characteristics: 10-day subcutaneous enzymatic electrochemical glucose sensor; BLE wireless data transmission to wearable reader; continuous interstitial glucose measurement in adults (≥ 18 years) with Type 1 or Type 2 diabetes mellitus; prescription use

Solstice submits that the Lumina CGM System shares the same intended use, the same fundamental technological characteristics (enzymatic electrochemical biosensing, subcutaneous implantation, BLE wireless data transmission to a wearable reader), and the same classification and product code as the GlucoTrack NX-500. The principal differences between the Lumina CGM System and the NX-500 — including the extended 14-day sensor wear duration (versus 10 days for the NX-500), the upgraded BLE 5.2 communication protocol, and the PtIr-4G electrode coating — do not raise new questions of safety and effectiveness and do not alter the fundamental scientific technology underlying the device. A detailed substantial equivalence comparison will be included in the Pre-Submission meeting package and, subsequently, in the 510(k) submission.

4.2 Secondary Predicate Device (Reference Device)

Solstice has also identified the following device as a secondary predicate (reference device) to support the substantial equivalence analysis:

NovaSense Medical Technologies Inc. GlucoTrack NX-700 CGM System

• 510(k) Number: K230489

• Date of Clearance: March 7, 2024

• Product Code: QKQ

• Classification: Class II

• Regulation Number: 21 C.F.R. § 862.1355

• Key Characteristics: 14-day subcutaneous enzymatic electrochemical glucose sensor; BLE 5.0 wireless data transmission to wearable reader; enhanced glucose prediction algorithm; continuous interstitial glucose measurement in adults (≥ 18 years) with Type 1 or Type 2 diabetes mellitus; prescription use

The GlucoTrack NX-700 is cited as a secondary predicate to demonstrate that the FDA has previously cleared a CGM system under product code QKQ with a 14-day sensor wear duration and enhanced BLE communication protocol — features shared by the Lumina CGM System. The NX-700 provides a relevant reference point for the Division's assessment of the Lumina CGM System's extended wear duration, updated wireless communication protocol, and algorithmic enhancements, each of which is consistent with features previously reviewed and cleared by the Agency.

4.3 Additional Reference

Solstice GlucoStrip RX-200 Test Strip Reader

• 510(k) Number: K192847

• Date of Clearance: November 14, 2019

• Product Code: NBW

• Classification: Class II

The GlucoStrip RX-200 is cited solely for the purpose of establishing SBI's corporate pedigree and prior FDA interaction history. As a blood glucose test strip reader under product code NBW, the GlucoStrip RX-200 is not being advanced as a predicate device for the Lumina CGM System's substantial equivalence determination. Rather, Solstice references this prior clearance to demonstrate SBI's familiarity with FDA's regulatory expectations, quality system requirements, and review processes for glucose monitoring devices, and to provide the Division with context regarding SBI's regulatory track record.

5. Regulatory History of Sponsor

Solstice Biomedical Inc.'s parent company, Solstice Biomedical Devices Ltd. (Dublin, Ireland), has an established history of regulatory engagement with the U.S. Food and Drug Administration and with international regulatory authorities. The following summarizes the key elements of the sponsor's regulatory history relevant to this Pre-Submission request:

• Prior FDA Clearance. Solstice Biomedical Devices Ltd. (through its U.S. subsidiary, SBI) previously obtained 510(k) clearance for the Solstice GlucoStrip RX-200 Test Strip Reader (510(k) No. K192847, cleared November 14, 2019, product code NBW, Class II). The GlucoStrip RX-200 remains commercially available in the United States and has maintained an active establishment registration and device listing throughout the post-clearance period.

• EU MDR CE Certification. The Lumina CGM System has been commercially available in the European Union since September 2024, following receipt of CE certification under Regulation (EU) 2017/745 (EU MDR) from Meridian Conformity Assessment GmbH, an EU-recognized Notified Body (Notified Body Identification No. 0483). The EU MDR CE Certificate for the Lumina CGM System bears Certificate Number MCA-2024-07319, issued September 12, 2024. The System has been commercially distributed in Ireland, Germany, France, the Netherlands, and the United Kingdom since that date. Post-market surveillance data collected since commercial launch will be available to the Division upon request and will be summarized in the Pre-Submission meeting package and the 510(k) submission.

• ISO 13485:2016 Certification. Solstice Biomedical Devices Ltd. holds current ISO 13485:2016 certification for the design, development, manufacture, and servicing of in vitro diagnostic glucose monitoring devices and continuous glucose monitoring systems. The ISO 13485:2016 certificate was issued by Meridian Conformity Assessment GmbH and covers all Solstice manufacturing and design facilities, including the primary manufacturing site in Chapelizod, Dublin, Ireland, and the design and engineering center in Cambridge, Massachusetts.

• No Existing FDA Clearance or Approval for the Lumina CGM System. Solstice confirms that the Lumina CGM System does not have any existing FDA clearance, approval, or De Novo classification. This Pre-Submission request represents the first FDA engagement for the Lumina CGM System in the United States.

6. Pre-Submission Meeting Request Details

In accordance with the FDA's Q-Submission Program guidance, Solstice provides the following details regarding the requested Pre-Submission meeting:

Meeting Type Requested: Q-Submission (Pre-Sub) meeting pursuant to 21 C.F.R. Part 807 and the FDA guidance document Requests for Feedback and Meetings for Medical Device Submissions: The Q-Submission Program (Revised January 2023).

Preferred Meeting Format: Teleconference. Solstice respectfully requests that the meeting be conducted via teleconference for the convenience of both parties, given the participation of attendees located in Dublin, Ireland, Cambridge, Massachusetts, Washington, D.C., and Rockville, Maryland. However, if the Division prefers an in-person meeting at the FDA White Oak campus in Silver Spring, Maryland, Solstice and its representatives are prepared to attend in person and will make all necessary arrangements.

Requested Meeting Date: On or around August 14, 2025. Solstice has selected this date to allow for the full 60-calendar-day review period following submission of the Pre-Submission meeting package. Solstice understands that the Division will confirm the meeting date and time based on reviewer availability, and Solstice is available for alternative dates within the two-week window surrounding August 14, 2025, should the requested date not be available.

Pre-Submission Meeting Package Submission Timeline: Solstice will submit the complete Pre-Submission meeting package to the Division no later than June 16, 2025, which is sixty (60) calendar days in advance of the requested August 14, 2025 meeting date. The Pre-Submission meeting package will be submitted electronically via the FDA's eSTAR electronic submission system.

Contents of the Pre-Submission Meeting Package: The Pre-Submission meeting package will include the following components:

1. Executive Summary — A concise overview of the Lumina CGM System, the proposed regulatory pathway, and the key topics and questions for discussion at the Pre-Submission meeting.

2. Detailed Device Description — Comprehensive technical description of the C14 Sensor, R7 Reader, associated firmware and software components, system architecture, and user interface design, supplemented with engineering drawings, system block diagrams, and photographs.

3. Predicate Comparison and Substantial Equivalence Discussion — A side-by-side comparison of the Lumina CGM System with the proposed primary predicate device (GlucoTrack NX-500, K211034) and secondary predicate device (GlucoTrack NX-700, K230489), including an analysis of intended use, technological characteristics, performance characteristics, and identification of differences with supporting rationale for substantial equivalence.

4. Proposed Performance Testing Plan — A summary of the bench testing, analytical performance testing, electrical safety and electromagnetic compatibility (EMC) testing, software verification and validation testing, biocompatibility testing, sterility/shelf-life testing, and wireless coexistence testing that Solstice proposes to conduct (or has already completed) in support of the 510(k) submission.

5. Proposed Clinical Study Protocol Summary — A summary of Protocol SBD-LUM-CL-001 ("LUMINA-US"), the prospective clinical study that Solstice proposes to conduct at U.S. clinical sites to generate clinical performance data for the 510(k) submission, including the study design, population, endpoints, sample size justification, statistical analysis plan, and site selection.

6. Specific Questions for FDA — The detailed questions that Solstice seeks the Division's feedback on at the Pre-Submission meeting, organized by topic area as summarized in Section 7 of this cover letter.

7. Summary of Topics and Questions for Discussion

Solstice intends to present the following categories of questions and topics for discussion at the Pre-Submission meeting. Detailed, fully developed questions will be included in the Pre-Submission meeting package to be submitted by June 16, 2025. The following provides a summary of the question categories to assist the Division in identifying the appropriate reviewers and subject-matter experts for the meeting:

Topic 1: Predicate Device Selection and Substantial Equivalence Framework. Solstice will seek FDA feedback on the acceptability of the proposed primary predicate device (GlucoTrack NX-500, K211034) and secondary predicate device (GlucoTrack NX-700, K230489) for the Lumina CGM System's substantial equivalence determination. Solstice will present the proposed substantial equivalence framework, identify the key differences between the Lumina CGM System and the proposed predicate devices, and request the Division's preliminary assessment of whether those differences raise new questions of safety and effectiveness that would require additional data or testing.

Topic 2: Clinical Study Design and Endpoints (LUMINA-US Study). Solstice will present the proposed design and endpoints for the LUMINA-US clinical study (Protocol SBD-LUM-CL-001), a prospective, single-arm, multicenter clinical study to be conducted at six (6) U.S. clinical sites enrolling approximately 350 subjects with Type 1 or Type 2 diabetes mellitus. The proposed primary performance endpoint is a mean absolute relative difference (MARD) of ≤ 9.0% compared to a reference blood glucose analyzer (e.g., Kestrel Partners LLC YSI 2300 or equivalent). The proposed secondary endpoints include demonstration of ≥ 99% of paired glucose values within Zones A and B of the Clarke Error Grid Analysis and ≥ 99% within the clinically acceptable zones of the Consensus Error Grid. Solstice will seek the Division's feedback on the adequacy and acceptability of the proposed study design, sample size, endpoints, reference method, and statistical analysis plan.

Topic 3: Investigational Device Exemption (IDE) Determination. Solstice intends to conduct the LUMINA-US clinical study under the IDE exemption for non-significant risk (NSR) diagnostic device studies set forth at 21 C.F.R. § 812.2(c)(3). Solstice will present its risk assessment supporting the NSR determination and will seek the Division's concurrence that the LUMINA-US study qualifies as a non-significant risk diagnostic device study exempt from the requirement to submit an IDE application, provided that the study is conducted in accordance with the abbreviated requirements of 21 C.F.R. Part 812 and under the oversight of local institutional review boards (IRBs) at each participating clinical site.

Topic 4: Software Documentation Requirements and Level of Concern. Solstice will present its proposed software documentation approach for the C14 Sensor firmware (Lumina Firmware v3.4.2), the R7 Reader operating system (Lumina Reader OS v2.1.0), the LuminaPredict Algorithm v2.1, and the Lumina Mobile App v1.0.3. Solstice proposes to designate the overall software level of concern as "Major" based on the potential for indirect patient harm through inaccurate glucose readings or delayed alerts. Solstice will seek the Division's feedback on the appropriateness of the "Major" level of concern designation and on the scope and depth of software documentation expected in the 510(k) submission, including any expectations regarding the submission of software hazard analysis, software requirements specification, architecture design documents, traceability matrices, and unit/integration/system-level test reports.

Topic 5: Cybersecurity Premarket Submission Expectations. Given that the Lumina CGM System incorporates BLE 5.2 wireless communication between the C14 Sensor and R7 Reader, BLE 5.2 communication between the R7 Reader and the Lumina Mobile App, and optional cloud-based data backup via the mobile application, Solstice will seek the Division's guidance on the cybersecurity documentation expected in the 510(k) submission. Solstice intends to address cybersecurity in accordance with the FDA guidance document Cybersecurity in Medical Devices: Quality System Considerations and Content of Premarket Submissions (September 2023) and will present a proposed threat model, cybersecurity risk assessment, software bill of materials (SBOM), and vulnerability disclosure plan. Solstice will seek the Division's feedback on the adequacy of the proposed cybersecurity approach and any additional cybersecurity testing or documentation expectations.

Topic 6: Biocompatibility Testing Scope. Solstice will present the proposed biocompatibility testing plan for the C14 Sensor (a subcutaneous implant device with a 14-day contact duration) and the R7 Reader (a skin-contact wearable device with a 14-day contact duration), developed in accordance with ISO 10993-1:2018 (Biological evaluation of medical devices — Part 1: Evaluation and review within a risk management process) and the FDA guidance document Use of International Standard ISO 10993-1, "Biological evaluation of medical devices — Part 1: Evaluation and review within a risk management process" (September 2020). Solstice will present the proposed biocompatibility testing endpoints for each component and will seek the Division's feedback on the adequacy of the testing scope, including whether any additional biological endpoints or testing (e.g., chronic toxicity, genotoxicity, hemocompatibility) are recommended for the C14 Sensor given the subcutaneous implantation and 14-day contact duration.

Topic 7: iCGM Classification Pathway Considerations. Solstice will seek the Division's preliminary feedback on whether the Lumina CGM System may qualify for integrated continuous glucose monitoring (iCGM) classification, including the applicable special controls, performance criteria, and any additional testing or documentation required to support an iCGM classification determination. Solstice is particularly interested in understanding the Division's expectations regarding accuracy performance at clinically critical glucose ranges (e.g., ≤ 70 mg/dL and ≥ 180 mg/dL), alert performance requirements, and interoperability requirements for iCGM-classified devices.

8. Proposed Attendee List

Solstice proposes the following individuals to attend the Pre-Submission meeting on behalf of the sponsor, its legal counsel, and its regulatory consultant. Solstice respectfully requests that the Division identify the FDA attendees in advance of the meeting so that Solstice may tailor its presentation to the expertise and review responsibilities of the participating FDA staff.

From Solstice Biomedical Inc. / Solstice Biomedical Devices Ltd.:

1. Dr. Niamh Tierney, RAC — Vice President, Regulatory Affairs, Solstice Biomedical Devices Ltd. (Dublin, Ireland). Dr. Tierney will serve as the lead regulatory presenter for the Pre-Submission meeting.

2. Marcus Hale — Vice President, U.S. Operations, Solstice Biomedical Inc. (Cambridge, MA). Mr. Hale will serve as the primary sponsor contact and administrative coordinator.

3. Dr. Aisling Burke — Chief Technology Officer, Solstice Biomedical Devices Ltd. (Dublin, Ireland). Dr. Burke will address technical questions regarding the C14 Sensor's PtIr-4G electrode technology, the R7 Reader hardware design, firmware and software architecture, and the LuminaPredict Algorithm.

4. Fiona Drennan — Quality Assurance Director, Solstice Biomedical Devices Ltd. (Dublin, Ireland). Ms. Drennan will address questions regarding quality system documentation, biocompatibility and sterilization validation, and manufacturing process controls.

From Calderwood & Harkness LLP:

5. Miriam Calloway, Esq. — Partner, Healthcare & Life Sciences Regulatory Practice. Ms. Calloway will serve as lead legal counsel and will address regulatory strategy, IDE exemption analysis, and procedural questions.

6. Amy Whitfield, Esq. — Lead Associate, Healthcare & Life Sciences Regulatory Practice. Ms. Whitfield will provide supporting legal and regulatory analysis.

7. Sean Morrissey, Esq. — Associate, Healthcare & Life Sciences Regulatory Practice. Mr. Morrissey will provide supporting research and documentation.

From Pinnacle Regulatory Consulting Group LLC:

8. Dr. Sandra Ellison — Managing Director. Dr. Ellison will provide subject-matter expertise on CGM device review expectations, performance testing, and clinical study design, drawing on her prior experience as a scientific reviewer in the Division of Chemistry and Toxicology Devices, CDRH.

9. Thomas Greenbaum — Senior Regulatory Specialist. Mr. Greenbaum will support the presentation of the predicate comparison and substantial equivalence analysis.

9. Enclosures

The following document is enclosed with this Pre-Submission Meeting Request cover letter:

1. FDA Form 3514 — Pre-Submission Meeting Request Form, completed and signed by Marcus Hale, VP of U.S. Operations, Solstice Biomedical Inc., on behalf of the sponsor.

Solstice notes that the complete Pre-Submission meeting package — including the executive summary, detailed device description, predicate comparison and substantial equivalence discussion, proposed performance testing plan, proposed clinical study protocol summary (Protocol SBD-LUM-CL-001, "LUMINA-US"), and specific questions for FDA feedback — will be submitted separately and electronically via the FDA's eSTAR electronic submission system no later than June 16, 2025, sixty (60) calendar days in advance of the requested meeting date of August 14, 2025. The meeting package submission will reference this Pre-Submission Meeting Request cover letter and the accompanying FDA Form 3514.

10. Contact and Correspondence Information

All correspondence regarding this Pre-Submission request, including meeting scheduling communications, feedback letters, and any requests for additional information, should be directed to:

Primary Contact:

Marcus Hale Vice President, U.S. Operations Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 Tel: (617) 482-9115

Fax: (617) 482-9101

Email: m.hale@solsticebiomedical.com

With a copy to:

Miriam Calloway, Esq. Partner, Healthcare & Life Sciences Regulatory Practice Calderwood & Harkness LLP 1401 K Street NW, Suite 900 Washington, D.C. 20005 Tel: (202) 654-8800

Fax: (202) 654-8801

Email: m.calloway@calderwoodharkness.com

Solstice authorizes the Division to communicate with either Mr. Hale or Ms. Calloway regarding any aspect of this Pre-Submission request and the anticipated 510(k) submission. Both contacts are authorized to receive confidential and trade-secret information on behalf of the sponsor.

Solstice Biomedical Inc. sincerely appreciates the Division's consideration of this Pre-Submission Meeting Request and the Agency's commitment to facilitating pre-submission dialogue with device sponsors. Solstice is confident that a productive Pre-Submission meeting will assist in the preparation of a high-quality, complete 510(k) submission for the Lumina CGM System, to the mutual benefit of the sponsor and the Agency, and ultimately in service of providing persons with diabetes access to an advanced, accurate, and reliable continuous glucose monitoring technology.

Solstice looks forward to a productive and collaborative dialogue with the Division of Chemistry and Toxicology Devices regarding the regulatory pathway and evidentiary expectations for the Lumina CGM System and stands ready to provide any additional information that the Division may require in connection with the scheduling or preparation for the Pre-Submission meeting.

Respectfully submitted,

SOLSTICE BIOMEDICAL INC.

By: ________

Name: Marcus Hale

Title: Vice President, U.S. Operations

Date: June 2, 2025

Prepared with the assistance of:

CALDERWOOD & HARKNESS LLP

By: ________

Name: Miriam Calloway

Title: Partner, Healthcare & Life Sciences Regulatory Practice

Date: June 2, 2025

cc: (via email)

Dr. Eoin Gallagher, Chief Executive Officer, Solstice Biomedical Devices Ltd. Dr. Niamh Tierney, Vice President of Regulatory Affairs, Solstice Biomedical Devices Ltd. Joel Strauss, Billing Partner, Calderwood & Harkness LLP Dr. Sandra Ellison, Managing Director, Pinnacle Regulatory Consulting Group LLC

Enclosure: FDA Form 3514 (Pre-Submission Meeting Request Form)

CONFIDENTIAL — PRE-SUBMISSION CORRESPONDENCE
SOLSTICE BIOMEDICAL INC. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 Tel: (617) 482-9100
Fax: (617) 482-9101
www.solsticebiomedical.com
June 2, 2025
Director, Division of Chemistry and Toxicology Devices Office of Health Technology 2 (OHT2) Center for Devices and Radiological Health (CDRH) U.S. Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993
Re: Pre-Submission (Q-Submission) Meeting Request — Solstice Lumina™ Continuous Glucose Monitoring System (Lumina C14 Implantable Sensor and Lumina R7 Wearable Reader/Transmitter)
Anticipated Product Code: QKQ Anticipated Regulation Number: 21 C.F.R. § 862.1355 Anticipated Device Classification: Class II
Dear Director and Members of the Division:
Solstice Biomedical Inc. ("Solstice" or "SBI"), a Delaware corporation (File No. 7834291), respectfully requests a Pre-Submission (Q-Submission) meeting with the Division of Chemistry and Toxicology Devices, Office of Health Technology 2, Center for Devices and Radiological Health ("CDRH"), in accordance with the guidance set forth in the FDA's Requests for Feedback and Meetings for Medical Device Submissions: The Q-Submission Program (Revised January 2023). The purpose of this request is to discuss the planned traditional 510(k) premarket notification submission for the Solstice Lumina™ Continuous Glucose Monitoring System (the "Lumina CGM System" or the "System"), comprising the Lumina C14 subcutaneously implantable continuous glucose monitoring sensor (the "C14 Sensor") and the Lumina R7 wearable reader/transmitter (the "R7 Reader").
SBI is the wholly-owned U.S. subsidiary of Solstice Biomedical Devices Ltd., a private limited company incorporated in Ireland (Companies Registration Office No. 648231), headquartered at Unit 14, Liffey Innovation Park, Chapelizod, Dublin D20 FX72, Ireland. SBI will serve as the intended 510(k) holder and U.S. agent for the Lumina CGM System and has been authorized by Solstice Biomedical Devices Ltd. to engage with the Agency on all regulatory matters related to U.S. market entry of the System. SBI has retained Calderwood & Harkness LLP as outside regulatory and legal counsel for this submission, and Pinnacle Regulatory Consulting Group LLC as its regulatory consulting partner, as further described below.
We submit this cover letter in advance of the complete Pre-Submission meeting package, which Solstice will submit no later than June 16, 2025, in conformance with the 60-calendar-day advance requirement for Pre-Submission meeting requests. The following sections provide sponsor information, a device description summary, the intended regulatory pathway, predicate device identification, topics and questions proposed for discussion, and administrative details necessary for the Agency's scheduling and review.
1. Sponsor Information
The sponsor and intended 510(k) holder for the Lumina CGM System is:
Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 United States Tel: (617) 482-9100
Fax: (617) 482-9101
The following individuals are designated as principal contacts for this Pre-Submission request and all related regulatory correspondence:
Primary Contact for Correspondence:
Marcus Hale Vice President, U.S. Operations Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 Tel: (617) 482-9115
Email: m.hale@solsticebiomedical.com
Regulatory Affairs Contact:
Dr. Niamh Tierney, RAC Vice President, Regulatory Affairs Solstice Biomedical Devices Ltd. Unit 14, Liffey Innovation Park Chapelizod, Dublin D20 FX72, Ireland Tel: +353 1 697-4200
Email: n.tierney@solsticebiomedical.ie
Legal Counsel (Authorized Representative):
Miriam Calloway, Esq. Partner, Healthcare & Life Sciences Regulatory Practice Calderwood & Harkness LLP 1401 K Street NW, Suite 900 Washington, D.C. 20005 Tel: (202) 654-8800
Email: m.calloway@calderwoodharkness.com
Ms. Calloway previously served as Senior Counsel, Office of the Chief Counsel, Center for Devices and Radiological Health, U.S. Food and Drug Administration (2011–2017), and is intimately familiar with the Division's review processes and the regulatory landscape governing in vitro diagnostic and continuous glucose monitoring devices.
Additional Counsel:
Amy Whitfield, Esq. Lead Associate, Healthcare & Life Sciences Regulatory Practice Calderwood & Harkness LLP 1401 K Street NW, Suite 900 Washington, D.C. 20005 Tel: (202) 654-8824
Email: a.whitfield@calderwoodharkness.com
Regulatory Consultant:
Pinnacle Regulatory Consulting Group LLC 9500 Medical Center Drive, Suite 210 Rockville, MD 20850 Tel: (301) 741-3200
Contacts:
•  Dr. Sandra Ellison, Managing Director
Email: s.ellison@pinnaclereg.com
•  Thomas Greenbaum, Senior Regulatory Specialist
Email: t.greenbaum@pinnaclereg.com
Dr. Ellison previously served as a scientific reviewer in the Division of Chemistry and Toxicology Devices, CDRH, and brings substantial expertise in the review and clearance of continuous glucose monitoring and electrochemical biosensor devices.
2. Device Description Summary
2.1 Product Line Overview
The Solstice Lumina™ CGM System is a next-generation, continuous glucose monitoring system designed to provide real-time, minimally invasive interstitial glucose measurement for the management of diabetes mellitus. The System is comprised of two hardware components — the Lumina C14 Sensor and the Lumina R7 Reader — together with supporting firmware, software, and a mobile application. Solstice intends to submit a single, integrated 510(k) premarket notification covering both the C14 Sensor and the R7 Reader as a unified system, as the components are designed, verified, and validated to function together and are not independently marketed or used.
2.2 Device Variant 1 — Lumina C14 Sensor
The Lumina C14 is a subcutaneously implantable, continuous glucose monitoring sensor with a maximum approved wear duration of fourteen (14) days (336 hours). The C14 Sensor employs a fourth-generation enzymatic electrochemical biosensor architecture utilizing Solstice's proprietary platinum-iridium electrode coating technology, designated internally as PtIr-4G. The PtIr-4G coating is engineered to enhance signal stability, reduce oxygen dependency, and extend sensor longevity over the full 14-day wear period.
Key technical specifications of the C14 Sensor include:
•  Sensing Mechanism: Fourth-generation enzymatic electrochemical biosensor (glucose oxidase-based) with PtIr-4G platinum-iridium electrode coating
•  Wear Duration: 14 days (336 hours), single-use, disposable
•  Implantation Site: Subcutaneous tissue, posterior upper arm (recommended) or abdomen (alternate)
•  Insertion Method: Single-use, spring-loaded applicator (Lumina C14 Applicator, included in sensor kit)
•  Measurement Range: 40–400 mg/dL
•  Data Sampling Rate: Every 60 seconds (1-minute intervals); averaged and transmitted every 5 minutes
•  Warm-Up Time: ≤ 60 minutes from insertion to first glucose reading
•  Wireless Communication: Bluetooth Low Energy (BLE) 5.2 protocol for one-way data transmission from the C14 Sensor to the R7 Reader
•  Power Source: Integrated silver oxide micro-battery (non-rechargeable, non-replaceable)
•  Biocompatible Materials: Medical-grade silicone housing, parylene-C conformal coating, platinum-iridium electrode, biocompatible adhesive patch (cyanoacrylate-free)
•  Sterilization: Ethylene oxide (EtO) sterilization; supplied sterile in sealed, single-use packaging
•  Embedded Firmware: Lumina Firmware v3.4.2
2.3 Device Variant 2 — Lumina R7 Reader
The Lumina R7 is a wearable reader and transmitter device designed to be worn on the posterior upper arm, in proximity to the C14 Sensor. The R7 Reader receives BLE data from the C14 Sensor, processes the glucose signal using Solstice's proprietary glucose prediction algorithm (LuminaPredict Algorithm v2.1), and displays real-time glucose values, trend arrows, and 8-hour trend graphs on an integrated 1.4-inch AMOLED touchscreen display. The R7 Reader also transmits processed glucose data via BLE to the Solstice Lumina™ mobile application installed on the user's personal smartphone (iOS and Android platforms supported).
Key technical specifications of the R7 Reader include:
•  Display: 1.4-inch AMOLED capacitive touchscreen, 320 × 320 pixel resolution
•  Data Reception: BLE 5.2 receiver; receives raw sensor data from C14 Sensor at 5-minute intervals
•  Data Processing: Onboard processing of glucose signal using LuminaPredict Algorithm v2.1 for noise filtration, trend calculation, and predictive glucose estimation
•  Displayed Information: Real-time glucose value (mg/dL), directional trend arrows (rapidly falling, falling, stable, rising, rapidly rising), 8-hour trend graph, time-in-range statistics
•  Alert Functionality: Configurable hypoglycemia alerts (default: ≤ 55 mg/dL), configurable hyperglycemia alerts (default: ≥ 250 mg/dL), rate-of-change alerts, signal loss alerts; audible, vibratory, and visual alert modalities
•  Alert Latency: ≤ 5 minutes from sensor measurement to alert notification
•  Mobile Application Communication: BLE 5.2 transmission to Solstice Lumina™ Mobile App v1.0.3 (compatible with iOS 16.0+ and Android 13.0+)
•  Data Storage: 90-day onboard glucose data storage; cloud backup via mobile application (optional, user-enabled)
•  Power Source: Rechargeable lithium polymer battery; battery life ≥ 14 days per full charge; USB-C charging
•  Water Resistance: IP67 rated (immersion to 1 meter for 30 minutes)
•  Wearability: Medical-grade silicone band with hypoallergenic adhesive patch; designed for continuous 14-day wear concurrent with C14 Sensor wear period
•  Operating System: Lumina Reader OS v2.1.0 (proprietary real-time embedded operating system)
2.4 Software Components
The Lumina CGM System incorporates the following software and firmware components, each of which will be documented in accordance with FDA guidance on the content of premarket submissions for software contained in medical devices and the FDA's premarket cybersecurity guidance:
1.  Lumina Firmware v3.4.2 — Embedded firmware on the C14 Sensor controlling electrochemical measurement acquisition, analog-to-digital conversion, signal conditioning, and BLE data transmission.
2.  Lumina Reader OS v2.1.0 — Proprietary real-time embedded operating system on the R7 Reader managing BLE data reception, algorithm execution, display rendering, alert management, and mobile application pairing.
3.  LuminaPredict Algorithm v2.1 — Proprietary glucose prediction and trend analysis algorithm executing on the R7 Reader. LuminaPredict employs an adaptive Kalman filter and machine learning-based signal processing to convert raw sensor current (nanoamperes) to calibrated glucose concentration (mg/dL) and to generate trend predictions and rate-of-change calculations.
4.  Lumina Mobile App v1.0.3 — Companion mobile application for iOS (16.0+) and Android (13.0+) platforms providing extended data visualization, glucose data sharing with healthcare providers, retrospective analysis, and optional cloud data backup. The mobile application is intended to complement — not replace — the R7 Reader display, and the System is designed to function fully without the mobile application.
2.5 Intended Use
The Solstice Lumina™ CGM System is intended for prescription use for the continuous monitoring of interstitial fluid glucose levels in persons aged 18 years and older with Type 1 or Type 2 diabetes mellitus. The System is intended to replace fingerstick blood glucose testing for diabetes treatment decisions, including insulin dosing, when used in conjunction with a compatible blood glucose meter for calibration verification. The System is not intended for use in persons under the age of 18, in pregnant women, in critically ill patients, or as a sole basis for making therapy adjustments without clinical judgment.
3. Intended Regulatory Pathway
Solstice intends to submit a traditional 510(k) premarket notification for the Lumina CGM System in accordance with Section 510(k) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 360(k)) and the implementing regulations at 21 C.F.R. Part 807, Subpart E. The Lumina CGM System will be submitted as a single, integrated device system encompassing both the C14 Sensor and the R7 Reader.
The anticipated regulatory classification parameters are as follows:
•  Product Code: QKQ (Electrode, Glucose, Subcutaneous)
•  Regulation Number: 21 C.F.R. § 862.1355 (Glucose test system)
•  Device Classification: Class II (with special controls)
Solstice notes that the classification of continuous glucose monitoring systems under product code QKQ and 21 C.F.R. § 862.1355 reflects the FDA's reclassification order that became effective in March 2024, which reclassified integrated continuous glucose monitoring systems from Class III (PMA) to Class II (510(k)) with special controls, provided that such devices meet the performance criteria and special controls identified in the reclassification order.
In addition to the traditional 510(k) pathway, Solstice also intends to explore during the Pre-Submission meeting whether the Lumina CGM System qualifies for integrated continuous glucose monitoring (iCGM) classification under the applicable special controls. Solstice believes that the System's performance characteristics — including its measurement accuracy, alert functionality, and sensor longevity — may support an iCGM classification determination, and Solstice seeks the Division's preliminary feedback on the criteria and evidentiary standards applicable to an iCGM classification for the Lumina CGM System. Solstice acknowledges that iCGM classification carries specific performance requirements and special controls, and Solstice is prepared to discuss how the Lumina CGM System's design and performance data align with those requirements.
4. Predicate Device Identification
4.1 Primary Predicate Device
Solstice has identified the following device as the primary predicate for the Lumina CGM System's 510(k) substantial equivalence determination:
NovaSense Medical Technologies Inc. GlucoTrack NX-500 CGM System
•  510(k) Number: K211034
•  Date of Clearance: June 18, 2022
•  Product Code: QKQ
•  Classification: Class II
•  Regulation Number: 21 C.F.R. § 862.1355
•  Key Characteristics: 10-day subcutaneous enzymatic electrochemical glucose sensor; BLE wireless data transmission to wearable reader; continuous interstitial glucose measurement in adults (≥ 18 years) with Type 1 or Type 2 diabetes mellitus; prescription use
Solstice submits that the Lumina CGM System shares the same intended use, the same fundamental technological characteristics (enzymatic electrochemical biosensing, subcutaneous implantation, BLE wireless data transmission to a wearable reader), and the same classification and product code as the GlucoTrack NX-500. The principal differences between the Lumina CGM System and the NX-500 — including the extended 14-day sensor wear duration (versus 10 days for the NX-500), the upgraded BLE 5.2 communication protocol, and the PtIr-4G electrode coating — do not raise new questions of safety and effectiveness and do not alter the fundamental scientific technology underlying the device. A detailed substantial equivalence comparison will be included in the Pre-Submission meeting package and, subsequently, in the 510(k) submission.
4.2 Secondary Predicate Device (Reference Device)
Solstice has also identified the following device as a secondary predicate (reference device) to support the substantial equivalence analysis:
NovaSense Medical Technologies Inc. GlucoTrack NX-700 CGM System
•  510(k) Number: K230489
•  Date of Clearance: March 7, 2024
•  Product Code: QKQ
•  Classification: Class II
•  Regulation Number: 21 C.F.R. § 862.1355
•  Key Characteristics: 14-day subcutaneous enzymatic electrochemical glucose sensor; BLE 5.0 wireless data transmission to wearable reader; enhanced glucose prediction algorithm; continuous interstitial glucose measurement in adults (≥ 18 years) with Type 1 or Type 2 diabetes mellitus; prescription use
The GlucoTrack NX-700 is cited as a secondary predicate to demonstrate that the FDA has previously cleared a CGM system under product code QKQ with a 14-day sensor wear duration and enhanced BLE communication protocol — features shared by the Lumina CGM System. The NX-700 provides a relevant reference point for the Division's assessment of the Lumina CGM System's extended wear duration, updated wireless communication protocol, and algorithmic enhancements, each of which is consistent with features previously reviewed and cleared by the Agency.
4.3 Additional Reference
Solstice GlucoStrip RX-200 Test Strip Reader
•  510(k) Number: K192847
•  Date of Clearance: November 14, 2019
•  Product Code: NBW
•  Classification: Class II
The GlucoStrip RX-200 is cited solely for the purpose of establishing SBI's corporate pedigree and prior FDA interaction history. As a blood glucose test strip reader under product code NBW, the GlucoStrip RX-200 is not being advanced as a predicate device for the Lumina CGM System's substantial equivalence determination. Rather, Solstice references this prior clearance to demonstrate SBI's familiarity with FDA's regulatory expectations, quality system requirements, and review processes for glucose monitoring devices, and to provide the Division with context regarding SBI's regulatory track record.
5. Regulatory History of Sponsor
Solstice Biomedical Inc.'s parent company, Solstice Biomedical Devices Ltd. (Dublin, Ireland), has an established history of regulatory engagement with the U.S. Food and Drug Administration and with international regulatory authorities. The following summarizes the key elements of the sponsor's regulatory history relevant to this Pre-Submission request:
•  Prior FDA Clearance. Solstice Biomedical Devices Ltd. (through its U.S. subsidiary, SBI) previously obtained 510(k) clearance for the Solstice GlucoStrip RX-200 Test Strip Reader (510(k) No. K192847, cleared November 14, 2019, product code NBW, Class II). The GlucoStrip RX-200 remains commercially available in the United States and has maintained an active establishment registration and device listing throughout the post-clearance period.
•  EU MDR CE Certification. The Lumina CGM System has been commercially available in the European Union since September 2024, following receipt of CE certification under Regulation (EU) 2017/745 (EU MDR) from Meridian Conformity Assessment GmbH, an EU-recognized Notified Body (Notified Body Identification No. 0483). The EU MDR CE Certificate for the Lumina CGM System bears Certificate Number MCA-2024-07319, issued September 12, 2024. The System has been commercially distributed in Ireland, Germany, France, the Netherlands, and the United Kingdom since that date. Post-market surveillance data collected since commercial launch will be available to the Division upon request and will be summarized in the Pre-Submission meeting package and the 510(k) submission.
•  ISO 13485:2016 Certification. Solstice Biomedical Devices Ltd. holds current ISO 13485:2016 certification for the design, development, manufacture, and servicing of in vitro diagnostic glucose monitoring devices and continuous glucose monitoring systems. The ISO 13485:2016 certificate was issued by Meridian Conformity Assessment GmbH and covers all Solstice manufacturing and design facilities, including the primary manufacturing site in Chapelizod, Dublin, Ireland, and the design and engineering center in Cambridge, Massachusetts.
•  No Existing FDA Clearance or Approval for the Lumina CGM System. Solstice confirms that the Lumina CGM System does not have any existing FDA clearance, approval, or De Novo classification. This Pre-Submission request represents the first FDA engagement for the Lumina CGM System in the United States.
6. Pre-Submission Meeting Request Details
In accordance with the FDA's Q-Submission Program guidance, Solstice provides the following details regarding the requested Pre-Submission meeting:
Meeting Type Requested: Q-Submission (Pre-Sub) meeting pursuant to 21 C.F.R. Part 807 and the FDA guidance document Requests for Feedback and Meetings for Medical Device Submissions: The Q-Submission Program (Revised January 2023).
Preferred Meeting Format: Teleconference. Solstice respectfully requests that the meeting be conducted via teleconference for the convenience of both parties, given the participation of attendees located in Dublin, Ireland, Cambridge, Massachusetts, Washington, D.C., and Rockville, Maryland. However, if the Division prefers an in-person meeting at the FDA White Oak campus in Silver Spring, Maryland, Solstice and its representatives are prepared to attend in person and will make all necessary arrangements.
Requested Meeting Date: On or around August 14, 2025. Solstice has selected this date to allow for the full 60-calendar-day review period following submission of the Pre-Submission meeting package. Solstice understands that the Division will confirm the meeting date and time based on reviewer availability, and Solstice is available for alternative dates within the two-week window surrounding August 14, 2025, should the requested date not be available.
Pre-Submission Meeting Package Submission Timeline: Solstice will submit the complete Pre-Submission meeting package to the Division no later than June 16, 2025, which is sixty (60) calendar days in advance of the requested August 14, 2025 meeting date. The Pre-Submission meeting package will be submitted electronically via the FDA's eSTAR electronic submission system.
Contents of the Pre-Submission Meeting Package: The Pre-Submission meeting package will include the following components:
1.  Executive Summary — A concise overview of the Lumina CGM System, the proposed regulatory pathway, and the key topics and questions for discussion at the Pre-Submission meeting.
2.  Detailed Device Description — Comprehensive technical description of the C14 Sensor, R7 Reader, associated firmware and software components, system architecture, and user interface design, supplemented with engineering drawings, system block diagrams, and photographs.
3.  Predicate Comparison and Substantial Equivalence Discussion — A side-by-side comparison of the Lumina CGM System with the proposed primary predicate device (GlucoTrack NX-500, K211034) and secondary predicate device (GlucoTrack NX-700, K230489), including an analysis of intended use, technological characteristics, performance characteristics, and identification of differences with supporting rationale for substantial equivalence.
4.  Proposed Performance Testing Plan — A summary of the bench testing, analytical performance testing, electrical safety and electromagnetic compatibility (EMC) testing, software verification and validation testing, biocompatibility testing, sterility/shelf-life testing, and wireless coexistence testing that Solstice proposes to conduct (or has already completed) in support of the 510(k) submission.
5.  Proposed Clinical Study Protocol Summary — A summary of Protocol SBD-LUM-CL-001 ("LUMINA-US"), the prospective clinical study that Solstice proposes to conduct at U.S. clinical sites to generate clinical performance data for the 510(k) submission, including the study design, population, endpoints, sample size justification, statistical analysis plan, and site selection.
6.  Specific Questions for FDA — The detailed questions that Solstice seeks the Division's feedback on at the Pre-Submission meeting, organized by topic area as summarized in Section 7 of this cover letter.
7. Summary of Topics and Questions for Discussion
Solstice intends to present the following categories of questions and topics for discussion at the Pre-Submission meeting. Detailed, fully developed questions will be included in the Pre-Submission meeting package to be submitted by June 16, 2025. The following provides a summary of the question categories to assist the Division in identifying the appropriate reviewers and subject-matter experts for the meeting:
Topic 1: Predicate Device Selection and Substantial Equivalence Framework. Solstice will seek FDA feedback on the acceptability of the proposed primary predicate device (GlucoTrack NX-500, K211034) and secondary predicate device (GlucoTrack NX-700, K230489) for the Lumina CGM System's substantial equivalence determination. Solstice will present the proposed substantial equivalence framework, identify the key differences between the Lumina CGM System and the proposed predicate devices, and request the Division's preliminary assessment of whether those differences raise new questions of safety and effectiveness that would require additional data or testing.
Topic 2: Clinical Study Design and Endpoints (LUMINA-US Study). Solstice will present the proposed design and endpoints for the LUMINA-US clinical study (Protocol SBD-LUM-CL-001), a prospective, single-arm, multicenter clinical study to be conducted at six (6) U.S. clinical sites enrolling approximately 350 subjects with Type 1 or Type 2 diabetes mellitus. The proposed primary performance endpoint is a mean absolute relative difference (MARD) of ≤ 9.0% compared to a reference blood glucose analyzer (e.g., Kestrel Partners LLC YSI 2300 or equivalent). The proposed secondary endpoints include demonstration of ≥ 99% of paired glucose values within Zones A and B of the Clarke Error Grid Analysis and ≥ 99% within the clinically acceptable zones of the Consensus Error Grid. Solstice will seek the Division's feedback on the adequacy and acceptability of the proposed study design, sample size, endpoints, reference method, and statistical analysis plan.
Topic 3: Investigational Device Exemption (IDE) Determination. Solstice intends to conduct the LUMINA-US clinical study under the IDE exemption for non-significant risk (NSR) diagnostic device studies set forth at 21 C.F.R. § 812.2(c)(3). Solstice will present its risk assessment supporting the NSR determination and will seek the Division's concurrence that the LUMINA-US study qualifies as a non-significant risk diagnostic device study exempt from the requirement to submit an IDE application, provided that the study is conducted in accordance with the abbreviated requirements of 21 C.F.R. Part 812 and under the oversight of local institutional review boards (IRBs) at each participating clinical site.
Topic 4: Software Documentation Requirements and Level of Concern. Solstice will present its proposed software documentation approach for the C14 Sensor firmware (Lumina Firmware v3.4.2), the R7 Reader operating system (Lumina Reader OS v2.1.0), the LuminaPredict Algorithm v2.1, and the Lumina Mobile App v1.0.3. Solstice proposes to designate the overall software level of concern as "Major" based on the potential for indirect patient harm through inaccurate glucose readings or delayed alerts. Solstice will seek the Division's feedback on the appropriateness of the "Major" level of concern designation and on the scope and depth of software documentation expected in the 510(k) submission, including any expectations regarding the submission of software hazard analysis, software requirements specification, architecture design documents, traceability matrices, and unit/integration/system-level test reports.
Topic 5: Cybersecurity Premarket Submission Expectations. Given that the Lumina CGM System incorporates BLE 5.2 wireless communication between the C14 Sensor and R7 Reader, BLE 5.2 communication between the R7 Reader and the Lumina Mobile App, and optional cloud-based data backup via the mobile application, Solstice will seek the Division's guidance on the cybersecurity documentation expected in the 510(k) submission. Solstice intends to address cybersecurity in accordance with the FDA guidance document Cybersecurity in Medical Devices: Quality System Considerations and Content of Premarket Submissions (September 2023) and will present a proposed threat model, cybersecurity risk assessment, software bill of materials (SBOM), and vulnerability disclosure plan. Solstice will seek the Division's feedback on the adequacy of the proposed cybersecurity approach and any additional cybersecurity testing or documentation expectations.
Topic 6: Biocompatibility Testing Scope. Solstice will present the proposed biocompatibility testing plan for the C14 Sensor (a subcutaneous implant device with a 14-day contact duration) and the R7 Reader (a skin-contact wearable device with a 14-day contact duration), developed in accordance with ISO 10993-1:2018 (Biological evaluation of medical devices — Part 1: Evaluation and review within a risk management process) and the FDA guidance document Use of International Standard ISO 10993-1, "Biological evaluation of medical devices — Part 1: Evaluation and review within a risk management process" (September 2020). Solstice will present the proposed biocompatibility testing endpoints for each component and will seek the Division's feedback on the adequacy of the testing scope, including whether any additional biological endpoints or testing (e.g., chronic toxicity, genotoxicity, hemocompatibility) are recommended for the C14 Sensor given the subcutaneous implantation and 14-day contact duration.
Topic 7: iCGM Classification Pathway Considerations. Solstice will seek the Division's preliminary feedback on whether the Lumina CGM System may qualify for integrated continuous glucose monitoring (iCGM) classification, including the applicable special controls, performance criteria, and any additional testing or documentation required to support an iCGM classification determination. Solstice is particularly interested in understanding the Division's expectations regarding accuracy performance at clinically critical glucose ranges (e.g., ≤ 70 mg/dL and ≥ 180 mg/dL), alert performance requirements, and interoperability requirements for iCGM-classified devices.
8. Proposed Attendee List
Solstice proposes the following individuals to attend the Pre-Submission meeting on behalf of the sponsor, its legal counsel, and its regulatory consultant. Solstice respectfully requests that the Division identify the FDA attendees in advance of the meeting so that Solstice may tailor its presentation to the expertise and review responsibilities of the participating FDA staff.
From Solstice Biomedical Inc. / Solstice Biomedical Devices Ltd.:
1.  Dr. Niamh Tierney, RAC — Vice President, Regulatory Affairs, Solstice Biomedical Devices Ltd. (Dublin, Ireland). Dr. Tierney will serve as the lead regulatory presenter for the Pre-Submission meeting.
2.  Marcus Hale — Vice President, U.S. Operations, Solstice Biomedical Inc. (Cambridge, MA). Mr. Hale will serve as the primary sponsor contact and administrative coordinator.
3.  Dr. Aisling Burke — Chief Technology Officer, Solstice Biomedical Devices Ltd. (Dublin, Ireland). Dr. Burke will address technical questions regarding the C14 Sensor's PtIr-4G electrode technology, the R7 Reader hardware design, firmware and software architecture, and the LuminaPredict Algorithm.
4.  Fiona Drennan — Quality Assurance Director, Solstice Biomedical Devices Ltd. (Dublin, Ireland). Ms. Drennan will address questions regarding quality system documentation, biocompatibility and sterilization validation, and manufacturing process controls.
From Calderwood & Harkness LLP:
5.  Miriam Calloway, Esq. — Partner, Healthcare & Life Sciences Regulatory Practice. Ms. Calloway will serve as lead legal counsel and will address regulatory strategy, IDE exemption analysis, and procedural questions.
6.  Amy Whitfield, Esq. — Lead Associate, Healthcare & Life Sciences Regulatory Practice. Ms. Whitfield will provide supporting legal and regulatory analysis.
7.  Sean Morrissey, Esq. — Associate, Healthcare & Life Sciences Regulatory Practice. Mr. Morrissey will provide supporting research and documentation.
From Pinnacle Regulatory Consulting Group LLC:
8.  Dr. Sandra Ellison — Managing Director. Dr. Ellison will provide subject-matter expertise on CGM device review expectations, performance testing, and clinical study design, drawing on her prior experience as a scientific reviewer in the Division of Chemistry and Toxicology Devices, CDRH.
9.  Thomas Greenbaum — Senior Regulatory Specialist. Mr. Greenbaum will support the presentation of the predicate comparison and substantial equivalence analysis.
9. Enclosures
The following document is enclosed with this Pre-Submission Meeting Request cover letter:
1.  FDA Form 3514 — Pre-Submission Meeting Request Form, completed and signed by Marcus Hale, VP of U.S. Operations, Solstice Biomedical Inc., on behalf of the sponsor.
Solstice notes that the complete Pre-Submission meeting package — including the executive summary, detailed device description, predicate comparison and substantial equivalence discussion, proposed performance testing plan, proposed clinical study protocol summary (Protocol SBD-LUM-CL-001, "LUMINA-US"), and specific questions for FDA feedback — will be submitted separately and electronically via the FDA's eSTAR electronic submission system no later than June 16, 2025, sixty (60) calendar days in advance of the requested meeting date of August 14, 2025. The meeting package submission will reference this Pre-Submission Meeting Request cover letter and the accompanying FDA Form 3514.
10. Contact and Correspondence Information
All correspondence regarding this Pre-Submission request, including meeting scheduling communications, feedback letters, and any requests for additional information, should be directed to:
Primary Contact:
Marcus Hale Vice President, U.S. Operations Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 Tel: (617) 482-9115
Fax: (617) 482-9101
Email: m.hale@solsticebiomedical.com
With a copy to:
Miriam Calloway, Esq. Partner, Healthcare & Life Sciences Regulatory Practice Calderwood & Harkness LLP 1401 K Street NW, Suite 900 Washington, D.C. 20005 Tel: (202) 654-8800
Fax: (202) 654-8801
Email: m.calloway@calderwoodharkness.com
Solstice authorizes the Division to communicate with either Mr. Hale or Ms. Calloway regarding any aspect of this Pre-Submission request and the anticipated 510(k) submission. Both contacts are authorized to receive confidential and trade-secret information on behalf of the sponsor.
Solstice Biomedical Inc. sincerely appreciates the Division's consideration of this Pre-Submission Meeting Request and the Agency's commitment to facilitating pre-submission dialogue with device sponsors. Solstice is confident that a productive Pre-Submission meeting will assist in the preparation of a high-quality, complete 510(k) submission for the Lumina CGM System, to the mutual benefit of the sponsor and the Agency, and ultimately in service of providing persons with diabetes access to an advanced, accurate, and reliable continuous glucose monitoring technology.
Solstice looks forward to a productive and collaborative dialogue with the Division of Chemistry and Toxicology Devices regarding the regulatory pathway and evidentiary expectations for the Lumina CGM System and stands ready to provide any additional information that the Division may require in connection with the scheduling or preparation for the Pre-Submission meeting.
Respectfully submitted,
SOLSTICE BIOMEDICAL INC.
By: ________
Name: Marcus Hale
Title: Vice President, U.S. Operations
Date: June 2, 2025
Prepared with the assistance of:
CALDERWOOD & HARKNESS LLP
By: ________
Name: Miriam Calloway
Title: Partner, Healthcare & Life Sciences Regulatory Practice
Date: June 2, 2025
cc: (via email)
Dr. Eoin Gallagher, Chief Executive Officer, Solstice Biomedical Devices Ltd. Dr. Niamh Tierney, Vice President of Regulatory Affairs, Solstice Biomedical Devices Ltd. Joel Strauss, Billing Partner, Calderwood & Harkness LLP Dr. Sandra Ellison, Managing Director, Pinnacle Regulatory Consulting Group LLC
Enclosure: FDA Form 3514 (Pre-Submission Meeting Request Form)

CONFIDENTIAL — PRE-SUBMISSION CORRESPONDENCE

SOLSTICE BIOMEDICAL INC.

CALDERWOOD & HARKNESS LLP

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