Contract analysis

I. Purpose and Scope Calderwood & Harkness LLP ("C&H") has been engaged by Solstice Biomedical Devices Ltd. ("SBD") and its U.S. subsidiary, Solstice Biomedical Inc. ("SBI"), to conduct a comprehensive review of the draft labeling package for the Solstice Lumina™ Continuous Glucose Monitoring System (the "Lumina CGM System" or "Lumina System"). The Lumina CGM System comprises two primary components: the Lumina C14 im

1. Instructions for Use (IFU): The multi-page patient-facing booklet providing comprehensive setup, operation, troubleshooting, and safety information for the Lumina CGM System (Draft Revision 04, dated March 15, 2025).

2. Package Labeling: Both the outer carton labeling for the C14 Sensor and R7 Reader, respectively, and the inner carton labeling for individual sensor pouches (Draft Revision 03, dated March 10, 2025).

3. Physician Labeling (Healthcare Professional Guide): The summary guide intended for prescribing healthcare professionals, covering clinical indications, contraindications, warnings, precautions, device specifications, and clinical study data summaries (Draft Revision 02, dated March 12, 2025). Our review has been conducted against the requirements of 21 C.F.R. Part 801 (Labeling), 21 C.F.R. § 809.10 (labeling for i

II. Regulatory Framework for Device Labeling A. Statutory and Regulatory Requirements The labeling of medical devices in the United States is governed by a comprehensive statutory and regulatory framework rooted in the FD&C Act and its implementing regulations. The following provisions are of principal relevance to the Lumina CGM System labeling review. Sections 501 and 502 of the FD&C Act. Section 501 (21 U.S.C. § 3

III. Summary of Draft Labeling Components Reviewed A. Instructions for Use (IFU) The draft IFU is a multi-page booklet (currently approximately 68 pages, Draft Revision 04, dated March 15, 2025) that has been adapted from the EU MDR IFU approved in connection with CE certificate MCA-2024-07319. The IFU is organized into the following principal sections: system overview and component descriptions; initial setup and mo

IV. General Labeling Deficiencies and Recommendations This section addresses labeling deficiencies that are cross-cutting—i.e., they affect multiple or all components of the labeling package. Section-specific deficiencies are addressed in subsequent sections of this memorandum. A. Establishment Identification (21 C.F.R. § 801.1 and § 801.63) Deficiency: The draft labeling, across all three components (IFU, package la

V. Indications for Use / Intended Use Statement A. Current Draft Language Review The draft labeling states the intended use of the Lumina CGM System as follows: "The Solstice Lumina™ Continuous Glucose Monitoring System is intended for the continuous monitoring of glucose levels in the interstitial fluid of persons with diabetes mellitus. The system is indicated for use in adults and children aged 4 years and older."

VI. Warnings and Precautions The warnings and precautions sections of the draft labeling are among the areas requiring the most substantial revision for U.S. compliance. FDA expects CGM device labeling to contain comprehensive, specific warnings and precautions that address the reasonably foreseeable risks associated with device use. The draft labeling, adapted from the EU MDR version, is incomplete in several respec

1. Adjunctive vs. Non-Adjunctive Use Warning. Deficiency: The draft labeling is ambiguous regarding whether the Lumina CGM System is intended for adjunctive use—requiring confirmatory fingerstick blood glucose testing before treatment decisions are made—or non-adjunctive use—permitting treatment decisions, including insulin dosing, to be made based solely on CGM readings without confirmatory fingerstick testing. The

2. MRI Safety Warning. Deficiency: The C14 implantable sensor contains metallic components, specifically a platinum-iridium (PtIr) electrode, which raises MRI safety concerns. The draft labeling includes an MRI conditional statement—"MR Conditional: The Lumina C14 sensor has been tested and found to be MR Conditional under specified conditions"—but critically fails to specify the conditions under which MRI is safe. S

3. CT/X-Ray and Other Imaging Modalities. Deficiency: The draft labeling does not contain any warning or precaution regarding the use of CT scans, X-rays, or other medical imaging modalities in patients wearing the C14 Sensor. Given that the sensor is implanted subcutaneously and contains metallic components, there is a reasonable potential for imaging artifacts that could interfere with diagnostic image interpretati

4. Interference Substances Warning. Deficiency: The list of substances known or expected to interfere with the accuracy of CGM glucose readings is materially incomplete in the draft labeling. The draft mentions only acetaminophen (paracetamol) as a potential interferent. FDA's expectations for CGM labeling, as reflected in the September 2023 iCGM guidance and in the labeling of predicate devices, require disclosure o

5. Sensor Wear Duration Warning. Deficiency: The draft labeling warns that the C14 Sensor "should not be worn longer than 14 days" but does not adequately explain the specific risks associated with extended sensor wear beyond the validated wear period. The warning is stated in a single sentence without elaboration. Recommendation: The sensor wear duration warning should be enhanced to include the following elements:

6. Altitude, Temperature, and Environmental Conditions. Deficiency: The draft labeling does not contain any warning or precaution regarding device performance at extreme altitudes, temperatures, or humidity levels. The Lumina CGM System's operating specifications—including the operating temperature range, humidity range, and altitude range—are not disclosed in the warnings section or elsewhere in the patient-facing I

1. Pediatric Use Precaution. Deficiency: The draft labeling does not include a statement that the safety and effectiveness of the Lumina CGM System have not been established in patients under 18 years of age. Given that the EU-approved indication includes children aged 4 years and older but the U.S. intended use will be limited to adults aged 18 years and older, it is essential that the U.S. labeling include a clear

2. Pregnancy and Gestational Diabetes. Deficiency: The draft labeling does not contain any precaution regarding use of the Lumina CGM System in pregnant patients or in patients with gestational diabetes mellitus (GDM). Pregnancy can alter glucose metabolism and interstitial fluid dynamics, potentially affecting CGM accuracy. Additionally, the LUMINA-US study excludes pregnant patients from enrollment. Recommendation:

3. Critically Ill Patients. Deficiency: The draft labeling does not include a precaution regarding the use of the Lumina CGM System in critically ill patients, hospitalized patients, or patients undergoing dialysis. These patient populations may present physiological conditions (e.g., hypoperfusion, edema, fluid shifts) that affect interstitial fluid glucose concentrations and, consequently, CGM accuracy. The LUMINA-

4. Electromagnetic Interference. Deficiency: The draft labeling includes a generic precaution regarding electromagnetic interference ("Keep the device away from strong electromagnetic fields") but does not reference the specific wireless communication technology used by the Lumina CGM System (BLE 5.2) or the potential sources of interference that could affect the BLE connection between the C14 Sensor and the R7 Reade

VII. Contraindications A. Current Draft Review The draft labeling lists two contraindications for the Lumina CGM System:

1. Patients with known allergy to sensor adhesive materials.

2. Patients unable to maintain minimum sensor body clearance from transmitter. Deficiency: This list is incomplete for the U.S. market and does not meet FDA's expectations for comprehensive contraindication labeling for CGM devices. The contraindication regarding "minimum sensor body clearance from transmitter" is vaguely worded and does not convey a specific clinical condition or patient characteristic. Additionally

1. Hypersensitivity to sensor materials. Patients with known hypersensitivity to platinum, iridium, or other materials used in the C14 Sensor (specifically the PtIr-4G electrode coating) should be listed as contraindicated. This contraindication is distinct from allergy to the adhesive materials and addresses a different risk.

2. Pediatric patients. Use in patients under 18 years of age should be listed as a contraindication, consistent with the intended use limitation and the absence of pediatric clinical data.

3. MRI procedures. If MRI conditional testing has not been completed or does not support MRI conditionality under specified parameters, the labeling should contraindicate use during MRI procedures. The contraindication should state that the C14 Sensor must be removed prior to MRI.

4. Dialysis and severe dehydration. If clinical data does not support the use of the Lumina CGM System in patients undergoing dialysis or experiencing severe dehydration (conditions that can significantly alter interstitial fluid glucose concentrations), these populations should be listed as contraindicated for device use.

5. Use with unvalidated AID systems. The labeling should contraindicate the use of the Lumina CGM System for dosing decisions with automated insulin delivery (AID) systems unless the device has been specifically validated and cleared by FDA for interoperability with such systems. This is a particularly important contraindication in the context of iCGM classification, as iCGM devices may be marketed for interoperabili

VIII. Sensor Insertion Instructions (IFU) The sensor insertion instructions are a critical component of the IFU from both a user safety and a regulatory compliance perspective. Errors or omissions in the insertion instructions can lead to serious adverse events, including infection, inaccurate glucose readings due to improper sensor placement, and physical injury to the patient. Our review of the draft sensor inserti

1. Anatomical Site Specification. Deficiency: The draft IFU refers to "the abdomen or upper arm" as the approved insertion sites for the C14 Sensor. However, the LUMINA-US clinical study protocol (SBD-LUM-CL-001) evaluates only the upper arm as the primary insertion site. Moreover, the primary predicate device (NovaSense GlucoTrack NX-500, K211034) is cleared for abdomen use only, while the secondary predicate device

2. Sensor Insertion Procedure Illustrations. Deficiency: The sensor insertion illustrations in the draft IFU depict a three-step insertion process (open package, position applicator, press to insert) but omit two important procedural steps. First, the illustrations do not include a skin preparation step (i.e., cleaning and disinfecting the insertion site prior to sensor placement). Second, the illustrations do not de

3. Sensor Removal and Disposal. Deficiency: The instructions for sensor removal in the draft IFU are brief—consisting of only two sentences—and do not adequately address sharps disposal requirements or biohazard handling procedures. Given that the C14 Sensor is a subcutaneously implanted device with a sharp insertion element, proper disposal guidance is essential for user safety and regulatory compliance. Recommendat

4. Aseptic Technique. Deficiency: The draft IFU does not emphasize the importance of aseptic technique during the sensor insertion process. Given that the C14 Sensor involves subcutaneous placement through a needle puncture, the risk of local infection at the insertion site is a genuine clinical concern. The absence of aseptic technique guidance in the IFU represents a significant patient safety gap. Recommendation:

IX. Software and Algorithm Labeling A. LuminaPredict Algorithm Labeling Deficiency: The draft labeling references the "LuminaPredict" algorithm in several places as the system component responsible for glucose prediction and trend arrow generation. However, the labeling does not describe, in patient-accessible language, what the algorithm does, what its inputs and outputs are, or what its clinical limitations may be.