Why Biosensors Will Revolutionize How Treatments Are Evaluated

Ever since our family received the diagnosis of Rett syndrome for my daughter, Jilly, in 2004, I have vowed to do all I can to help advance research, so that one day a cure will be found. This includes participating in clinical research studies, which help researchers and companies prepare for clinical trials. When we learn about studies, we figure out what it entails and, if Jilly is eligible, we enroll her.

Recently we enrolled her in a study for biosensors, funded by RSRT, at Boston Children’s Hospital. The study is testing sensors that can record physiological data – such as heart rate, breathing patterns, and sleep, among other things – to see how well they measure Rett symptoms.

To be honest, at first this study didn’t excite me too much. I have always thought of the studies involving some sort of medicine to hopefully “fix” the symptoms as the most exciting. At our first visit for the study we learned how and when to apply the sensors and how to electronically track our observations. We learned about a data collecting device, called the Emerald, that would be in Jilly’s room during the study. The part that I was most looking forward to was receiving a report of Jilly’s data at the end of the study.

When I emailed RSRT CEO Monica Coenraads about the appointment, her response switched on a lightbulb in my head:

“Thank you for participating, Jennifer. These sensors will end up playing a critical role in trials and figuring out whether a therapeutic actually works or not. Eventually sensors will replace the currently used subjective scales that ask parents and clinicians to interpret how they think a child is doing.”

It was then that I realized why this study and studies like it are crucial to the future of potential curative strategies: By creating new tools to measure symptoms, we revolutionize how treatment effectiveness is tested. This is HUGE. I realized this is just as important and exciting as a potential therapeutic.

So that all parents and caregivers understand the importance of the biosensors study, I interviewed RSRT Chief Scientific Officer Jana Von Hehn about it.

1. Hi Jana! What is your role within the biosensor initiative?
I run all of RSRT’s clinical research studies, including our biosensor development work. I help identify the most promising new biosensors and test them in studies at our clinical sites like Boston Children’s. The ultimate goal is to show that biosensors can accurately measure symptoms at home so that biopharmaceutical companies can reliably use them in their clinical trials to detect changes over time to determine if a therapeutic is having a positive impact.

2. What exactly are biosensors and what do they do?
Biosensors are special sensors that can record and measure something about your body or its function, such as breathing, heart rate, position, motion, sleep, walking, etc. ECG that measures heart function and heart beat, and EEG that records brain waves and can detect seizures, determine sleep stages, and other brain functions are biosensors commonly used in the clinic. We are working to develop sensors like these that can be used at home

3. Why is the biosensor initiative important to RSRT?
Developing biosensors to measure symptoms provides a way for biopharmaceutical companies to objectively test the effects of their therapies directly in patients. It allows us to observe and quantify symptoms that can’t otherwise be reliably collected or evaluated, like the variability between heart beats, the number of breath holds and rapid breathing events, or how long they last and when they occur. Biosensors allow us to capture continuous information over days, weeks, months, or longer. They also allow us to get a picture of symptom impact, which provides more information and should be more representative than what is collected or observed in a few hours for an office visit in a research study, or even what you may find in an overnight sleep study.

By creating objective measurements, we can see how a therapeutic is affecting a patient directly by measuring something before and after a treatment. Currently, we rate patient symptoms by having someone (the clinician or the parent) rate how that patient is doing on a symptom rating scale or by answering a questionnaire. Scores can vary based on who is evaluating the patient. Often, different raters of the same participant (for example, a mom and a dad) can have different enough scores on a rating scale that a common clinical trial requirement is that the rater (whether the parent or the clinician), can’t change during the study. This serves as a way to reduce differences in scores due to different raters, or rater bias. Biosensors eliminate rater bias because they always measure the symptom the same way.

4. Can you explain the differences/pros/cons between "wearables" and "invisibles?"
“Wearables” are sensors that you wear – they attach or fit to your body, like a sticker, a fitted shirt, or a watch band. Some examples are an apple watch and a Fitbit. Invisibles are sensors that do not touch your body at all. These are new and very cool. “Invisibles” bounce a wave, like a radio wave, off of your body and can measure what is happening in your body by understanding how your body function changes the reflection of the wave. Invisibles are typically freestanding objects that are placed near you, like in your bedroom, and can bounce the waves off of you when you are nearby. The Emerald is an “invisible,” and it’s one of the devices being evaluated in the study that Jilly is participating in.

Pros and cons will vary by the device. As an invisible tracking device, the Emerald can only detect a signal if the person is nearby, so the data collected will be limited to time spent at home. But there is no burden to the patient or their family, and they can live their lives normally while the device gathers symptom information by itself. Wearables can go anywhere the patient goes but usually need to be removed and charged on a schedule, and close contact of the device may cause skin discomfort or be uncomfortable. So in this case, a different window of data can be collected, but there is more for parents and patients to do, which means a higher burden at home. Nonetheless, we are working with both wearables and invisibles so there will be a range of devices available for biopharmaceutical companies to choose from, depending on the design of their clinical trial and what symptoms the drug may be most likely to impact.

5. What are you most excited about when you look to the future of biosensors?
Developing biosensors for use at home has the potential to completely change how we measure therapeutic benefit in Rett. It would be the first time we see directly into what a patient is experiencing. As the technologies advance we’ll be able to measure more and more symptoms, and knowing more about what patients are experiencing will enable us to care for Rett patients better and better.

6. How do you choose a biosensor to develop?
We look for biosensors that can measure the highest number of symptoms, are easy for families to use, and generate good quality data that we can analyze. Right now we are focused on testing biosensors that can measure symptoms that should correct themselves on their own if MECP2 protein is restored in the brain. We are starting with breathing, sleep, and heart rate, all of which are disrupted in Rett. But we hope to expand what we can measure to include skills such as walking, hand use, and others that may take more time and learning to correct if MECP2 is restored.

Learn more about biosensors by watching the biosensors webinar: "Assessing Rett Symptoms with Cutting Edge Biosensors and Invisible Technology," from April 27, 2021.