To get more information and insights about the technologies at the forefront of diabetes management, MPO recently spoke to Mona Eskandarian, director of project management, general medicine and cardiovascular, for PPD, Thermo Fisher Scientific's clinical research business.
Sam Brusco: What are the trends right now in continuous glucose monitoring technology?
Mona Eskandarian: There are different continuous glucose monitoring (CGM) device technologies and vendors available commercially that are also utilized in clinical research. The devices provided by these vendors vary very much when it comes to capabilities. The main differences lie in: sensor life (10 days vs. 14 days); how data is obtained from the CGM device (e.g., through a reader or in real time via an app); and the device’s recording intervals over the sensor life (e.g., every five or 15 minutes). When choosing which device to use in a clinical trial, it is important to assess the best suitable device based on the protocol requirements and the geographic availability of the commercial device.
Earlier generations of CGM devices would require the patient to scan the sensor with a reader at certain intervals to collect sensor data and upload to a computer for readout; otherwise, data would be lost. Nowadays, we see more and more use of CGM devices where sensor data is transmitted without any human interaction (automatically through Bluetooth to an app on the patient’s mobile phone). By partnering with vendors providing digital health platforms, the app can be configured to allow or disable the patient’s view of their data, so participants in a clinical study will not have access to data if they are blinded.
In clinical research, the use of CGM devices is especially effective in decentralized clinical trials, where data can be collected remotely from the patient and uploaded with minimal human interaction. CGM technology is mainly used in Type 1 and 2 diabetes clinical studies where secondary endpoints and efficacy are assessed by looking at time-in-range values before and after treatment. Real-time CGM data are also used to support dose titration/adjustments while participating in a clinical study. Lately, there is also a move toward using CGM in non-diabetes studies where certain glucose targets are set to enforce lifestyle changes; for example, in obesity studies or with high-performance athletes.
CGM devices generate a lot of data, >1300 data points per patient visit, when used in clinical research. The proper analysis and review of the data generated from CGM devices requires use of data “lakes” from which dashboards are created, containing visualizations that can be used for safety monitoring and identification of hypoglycemic (low blood sugar) events, compliance monitoring and scientific surveillance on the clinical research data.
When reviewing CGM data, it is important to understand how the data collected from a CGM wearable can be impacted and to ensure correct interpretation when compared to glucose values from a traditional finger prick in diabetes studies. CGM and finger prick or plasma glucose measurements may not always agree. This is due to the gradient in glucose levels that may exist between the two different compartments where the glucose measurements are made (interstitial space for CGM vs. plasma or blood).
In addition, external pressure from a lounge chair or bed to the site where the CGM sensor is inserted can cause low values due to decreased blood flow to a pressured area. This should not be considered a fault, since the sensor actually measures the true glucose value in interstitial fluid in subcutaneous tissue at that point in time. CGM data can also be impacted by patient use, for example—sensor displaced, sensor deliberately removed or sensor failure, resulting in lower device compliance
Lastly, when using a device where CGM data is transmitted automatically to an app on a mobile phone, connectivity is critical to ensuring continuous data can be collected. Proactive measures to verify and mitigate these challenges are important for the success of the trial.
Brusco: How does integration of CGM with insulin pump technology advance diabetes management strategy?
Eskandarian: Recently, various hybrid closed-loop systems have become commercially available. These systems maintain glucose levels within a target range through use of a computerized algorithm to adjust the basal rate of insulin and administer corrective bolus doses. They are called “hybrid” systems because, unlike, fully closed-loop systems, the user is still required to manually program insulin boluses with meals.
Another development is the development of dual hormone systems, where there is an incorporation of glucagon and insulin. The use of these closed-loop systems is not without risk, as they have not undergone extensive testing, nor are they approved by the FDA.Brusco: How are eDiaries assisting diabetes patients with managing their condition? How can they still be improved?
Eskandarian: By documenting an individual’s dietary habits, daily activities, glucose measures, dose of anti-diabetic medication, and hypoglycemic or hyperglycemic events, eDiaries can help patients discover trends in their behavior that result in hypo or hyper events, and help them learn how to proactively take measures to prevent such events in the future.
In the past, patients had to manually document their glucose values (obtained from a glucometer or CGM device). We see that companies are now moving towards a more interfaced approach, where values from the glucometers and/or CGM devices are automatically uploaded in the eDiary, removing the chances of human error in transcription or “forgetting “ to document the value, making the eDiary more reliable.
We also see in clinical trials, use of eDiaries is gaining importance to include the patient’s voice. In patient-centric clinical trials (where patients are placed at the center of the research process), patient eDiaries play a crucial role in providing real-time insights into patient experiences, preferences, and outcomes. These diaries empower patients by allowing them to record their experiences throughout the study from their own natural environment.
The eDiary can be a powerful tool contributing to collecting data around the assessment of safety and efficacy of the drug under investigation. But at the same time, it brings its own challenges that, when not proactively managed, may affect data integrity of the clinical trial it is being used in. When programming eDiaries for use in a clinical trial, proper measures must be taken to safely store and transmit the patient’s health information. Furthermore, patient compliance in completing the eDiary consistently and in a timely manner, as well as the patient’s technology savviness or device combability, may cause a burden and decrease patient motivation to keep the eDiary up to date.
Ensuring the eDiary is user-friendly and intuitive for collecting current data (as opposed to retrospective data the patient needs to recall) contributes to patient adherence. When used in pediatric studies, it is also important to ensure the design and language used in an eDiary is adjusted to the subject’s age. Finally, allowing for more interfaces between different devices and wearables (e.g., glucometer, activity tracker, CGM device, etc.) and the eDiary deceases the risk of data entry errors or data gaps and increases the reliability of the data collected for inclusion in the endpoint measures of a clinical study.
Find more information about these technologies in the feature article "The Sweet Science of Diabetes Technology"