Contract analysis

I. Introduction and Purpose of Questions This section of the Pre-Submission (Q-Submission) Meeting Package sets forth specific questions that Solstice Biomedical Inc. ("Solstice" or "SBI") respectfully requests the U.S. Food and Drug Administration ("FDA"), Center for Devices and Radiological Health ("CDRH"), to address during the Pre-Submission meeting currently scheduled for August 14, 2025. The questions presented

1. Lumina C14 Implantable Sensor — A subcutaneously implanted, enzymatic electrochemical continuous glucose monitoring sensor with a 14-day functional wear duration. The C14 sensor employs a proprietary platinum-iridium electrode coating designated PtIr-4G.

2. Lumina R7 Wearable Reader/Transmitter — An arm-worn wearable device that wirelessly receives glucose data from the C14 sensor via Bluetooth Low Energy (BLE) 5.2 communication, processes the data through the proprietary LuminaPredict v2.1 glucose prediction algorithm, and displays real-time glucose readings and trend information to the user. The R7 reader also transmits data to the companion Lumina Mobile App (v1.0

1. Predicate Acceptance and Substantial Equivalence Framework

2. Acceptability of Proposed Clinical Study Design and Endpoints

3. IDE Exemption Applicability for Non-Significant Risk Study

4. Software Documentation Requirements and Level of Concern Designation

5. Cybersecurity Premarket Submission Expectations

6. Biocompatibility Testing Scope Adequacy 7. iCGM Classification Pathway Considerations For each topic area, Solstice provides brief contextual information to frame the question(s), followed by the specific question(s) for FDA. A consolidated summary table of all questions is provided in Section IX for ease of reference during the Pre-Submission meeting.

II. Topic 1: Predicate Acceptance and Substantial Equivalence Framework Context Solstice has undertaken a thorough review of legally marketed devices in order to identify appropriate predicate devices for purposes of establishing substantial equivalence of the Lumina CGM System under Section 510(k) of the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 360(k). Based on this review, Solstice has identified the follo

1. Sensor Wear Duration: The Lumina C14 sensor is designed for 14-day continuous wear, compared to the 10-day wear duration of the NX-500 sensor. Solstice notes that this difference is bridged by the secondary predicate NX-700 (K230489), which also features a 14-day sensor wear duration.

2. Electrode Material: The Lumina C14 sensor employs a proprietary platinum-iridium electrode with a PtIr-4G coating, whereas the NX-500 sensor uses a platinum electrode. The PtIr-4G coating was developed by Solstice to enhance sensor stability and reduce signal drift over the extended 14-day wear period. While the base electrode material (platinum) is shared between the devices, the addition of iridium and the propr

3. BLE Version: The Lumina CGM System uses Bluetooth Low Energy version 5.2 for wireless communication between the C14 sensor and the R7 reader, and between the R7 reader and the companion mobile application. The NX-500 uses an earlier version of BLE (the NX-700 secondary predicate uses BLE 5.0). BLE 5.2 offers enhanced data throughput, improved connection stability, and additional security features compared to earli

4. Reader Form Factor: The Lumina R7 reader/transmitter is an arm-worn wearable device, whereas the NX-500 employs a handheld receiver. The change in form factor is intended to improve user convenience and enable continuous, hands-free glucose monitoring. The core functionality of the reader — receiving sensor data, processing the data through the glucose algorithm, and displaying glucose readings — remains substanti

5. Algorithm: The Lumina CGM System employs the Solstice proprietary glucose prediction algorithm designated LuminaPredict v2.1, which differs from the NovaSense algorithm used in both predicate devices (NX-500 and NX-700). The LuminaPredict v2.1 algorithm was developed by Solstice's internal software and data science teams and has been validated against both laboratory glucose reference data and clinical data genera

III. Topic 2: Acceptability of Proposed Clinical Study Design and Endpoints Context Solstice proposes to conduct a pivotal clinical study to generate the clinical data necessary to support the 510(k) submission for the Lumina CGM System. The study, designated Protocol SBD-LUM-CL-001 and titled "LUMINA-US," is described in summary below. A detailed protocol synopsis is provided in the companion section of this Pre-Sub

IV. Topic 3: IDE Exemption Applicability for Non-Significant Risk Study Context Solstice anticipates that the LUMINA-US clinical study (Protocol SBD-LUM-CL-001) will qualify for the Investigational Device Exemption (IDE) exemption applicable to non-significant risk (NSR) diagnostic device studies under 21 C.F.R. § 812.2(c)(3). Under this provision, a clinical study of a diagnostic device may be exempt from the full I

1. Diagnostic Device: The Lumina CGM System is a diagnostic device intended to continuously measure interstitial glucose concentrations and display glucose readings to the user. The device does not directly administer therapy, control drug delivery, or actuate any therapeutic intervention. The device is not an automated insulin dosing controller and does not autonomously adjust insulin delivery.

2. Superficial Implantation: The Lumina C14 sensor is implanted subcutaneously (i.e., in the subcutaneous tissue beneath the skin) at a shallow insertion depth. The implantation procedure is minimally invasive, performed by the user via a spring-loaded applicator, and does not involve deep tissue, organ, or vascular implantation. The sensor is designed to be easily removed by the user at the end of the 14-day wear pe

3. Limited Duration of Implantation: The C14 sensor wear duration is 14 days (336 hours), after which the sensor is removed and discarded. This duration falls within the range of existing legally marketed CGM sensors that have been studied under NSR protocols.

4. Historical Precedent: Similar CGM clinical studies, including studies of subcutaneously implanted enzymatic electrochemical glucose sensors with comparable or longer sensor wear durations, have historically been determined to be non-significant risk studies. Solstice is aware that multiple prior CGM 510(k) submissions have been supported by clinical data generated under NSR study protocols with IRB oversight.

5. No Adjunctive Use Limitation Removed: The LUMINA-US study protocol does not direct subjects to make insulin dosing decisions based solely on the Lumina CGM System readings. Subjects will be instructed to confirm glucose readings with a blood glucose meter before making treatment decisions, consistent with standard CGM study protocols. IRB Oversight. Under the NSR determination, the LUMINA-US study would proceed un

V. Topic 4: Software Documentation Requirements and Level of Concern Designation Context The Lumina CGM System incorporates multiple software components that are integral to the device's intended function. These software components collectively govern sensor data acquisition, signal processing, glucose value computation, data display, wireless communication, and data storage. Each software component has been develope

1. Lumina Firmware v3.4.2 — Embedded software resident on the Lumina C14 sensor. This firmware controls sensor electrode excitation, analog-to-digital conversion of sensor signals, initial signal processing, and BLE data transmission from the sensor to the R7 reader. The firmware operates on a low-power microcontroller within the sensor assembly.

2. Lumina Reader OS v2.1.0 — Operating software resident on the Lumina R7 wearable reader/transmitter. This software manages BLE communication with the C14 sensor, receives and processes raw sensor data, applies the LuminaPredict glucose prediction algorithm, generates glucose readings and trend displays, manages alert and alarm functions, and communicates with the companion Lumina Mobile App via BLE.

3. LuminaPredict Algorithm v2.1 — A proprietary glucose prediction algorithm developed by Solstice's data science team. The algorithm receives processed sensor signals from the R7 reader OS, applies calibration models and signal correction routines, and outputs real-time glucose concentration values and glucose trend predictions. The algorithm was developed using machine learning techniques applied to a training data

4. Lumina Mobile App v1.0.3 — A companion mobile application available on iOS and Android platforms. The mobile application receives glucose data from the R7 reader via BLE, displays real-time and historical glucose readings, generates glucose trend reports, and enables data sharing with healthcare providers via a secure cloud-based data platform. The mobile application does not independently generate glucose reading

VI. Topic 5: Cybersecurity Premarket Submission Expectations Context The Lumina CGM System employs wireless communication technologies and cloud-based data infrastructure that necessitate robust cybersecurity considerations. Solstice has developed a comprehensive cybersecurity program for the Lumina CGM System and seeks FDA's input on specific cybersecurity documentation expectations for the 510(k) submission. Wirele

VII. Topic 6: Biocompatibility Testing Scope Adequacy Context Biocompatibility testing for the Lumina CGM System is being conducted in accordance with ISO 10993-1:2018 (Biological evaluation of medical devices — Part 1: Evaluation and review within a risk management process). The biocompatibility evaluation follows a risk-based approach, considering the nature of patient contact, the duration of contact, and the spec

VIII. Topic 7: iCGM Classification Pathway Considerations Context In 2018, FDA established the integrated Continuous Glucose Monitoring (iCGM) device classification through De Novo classification order DEN170088, creating a new regulatory classification for CGM devices that meet specified performance criteria and are designed to be interoperable with other compatible medical devices, such as automated insulin dosing

IX. Summary of Questions The following table consolidates all questions presented in this Pre-Submission meeting package, organized by topic area, for ease of reference during the Pre-Submission meeting. Total: 26 questions across 7 topic areas.

X. Cross-References to Other Pre-Sub Package Sections The questions presented in this document should be considered in conjunction with the companion sections of the Pre-Submission meeting package. Solstice respectfully directs FDA's attention to the following sections for additional context and technical detail:

1. Executive Summary — Provides a high-level overview of the Lumina CGM System, the regulatory strategy, and the purpose of the Pre-Submission meeting request.

2. Device Description — Contains detailed technical descriptions of the Lumina C14 sensor and R7 reader/transmitter, including materials of construction, dimensions, operating principles, software versions (Lumina Firmware v3.4.2, Lumina Reader OS v2.1.0, LuminaPredict Algorithm v2.1, Lumina Mobile App v1.0.3), performance specifications, and labeling.

3. Predicate Comparison and Substantial Equivalence Discussion — Provides a detailed comparison of the Lumina CGM System to the primary predicate (NovaSense GlucoTrack NX-500, K211034) and secondary predicate (NovaSense GlucoTrack NX-700, K230489), including a comprehensive predicate comparison matrix, analysis of technological differences, and Solstice's argument for substantial equivalence.

4. Proposed Performance Testing Plan — Describes the bench testing, biocompatibility testing (at Whitmore Laboratories Inc.), electromagnetic compatibility (EMC) testing, software verification and validation (V&V), and other non-clinical testing proposed to support the 510(k) submission.

5. Proposed Clinical Study Protocol Summary — Provides a detailed synopsis of Protocol SBD-LUM-CL-001 (LUMINA-US), including study objectives, study design, subject selection criteria, study procedures, endpoints, statistical analysis plan, and safety monitoring plan. These companion sections are submitted together with this Questions document as a unified Pre-Submission meeting package.

XI. Meeting Logistics and Attendees Meeting Format and Date Solstice respectfully requests that the Pre-Submission meeting be conducted via teleconference. The target meeting date is August 14, 2025, consistent with the standard 75-day timeline for Pre-Submission meeting scheduling following FDA's receipt of the Q-Submission package. Proposed Attendees Solstice proposes the following attendees for the Pre-Submission

XII. Closing Solstice Biomedical Inc. sincerely appreciates FDA's willingness to engage in the Pre-Submission process and to provide feedback on the regulatory, clinical, and technical questions presented in this meeting package. The guidance received through this Pre-Submission interaction will be instrumental in shaping Solstice's 510(k) submission strategy and ensuring that the submission is complete, well-support