The eCOA captures how patients feel and function, a few scheduled points at a time. Wearables record what the body does in between. With Ametris now part of Signant Health, sponsors can pair the patient reported outcomes with a continuous, validated physiological signal, and obtain multiple lines of evidence for a more complete picture of a patient. A daily diary captures how a patient feels in a moment. A clinician visit captures a single day, once every few weeks. These are the scheduled points a trial is built around, and they remain the measure of record. Between them, and through every night, the same patient keeps living with the condition, and a wearable can follow that continuously. The eCOA is still the foundation of efficacy measurement, and rightly so: patient-reported, clinician-reported and performance outcomes are how a patient's experience becomes the endpoints regulators accept and sponsors report. A sensor does not fill a gap in that measure or correct it. It adds an independent, physiological perspective on the same experience, so the evidence a programme works from is fuller and better corroborated.
Wearables do not replace that measure. They observe the same underlying experience continuously, adding a sensor layer that stands alongside the endpoint rather than competing with it.
One platform, two modalities
Ametris, formerly ActiGraph and now part of Signant Health, brings two decades of wearable-sensor science to clinical measurement. Its methods appear in more than 30,000 peer-reviewed publications and have established regulatory precedent at the FDA, the EMA and agencies worldwide across CNS, cardiovascular, oncology and respiratory programmes. The platform is device-agnostic, spanning the ActiGraph LEAP multi-sensor wearable and validated third-party devices, so the measurement fits the scientific question rather than the reverse.
That combination is the point of difference. A sensor is easy to add to a trial; a defensible endpoint is not. Sponsors have generally had to assemble the patient-reported side and the device side from different suppliers and then reconcile the science and the regulatory story themselves. Bringing eCOA and validated wearable measures together, under a single measurement and regulatory team, is what turns two data streams into one coherent evidence package.
The same enhancement, across therapeutic areas
The opportunity is not confined to one disease or one device. In oncology, CNS and rheumatology, continuous physical-activity data, steps, intensity and sedentary time, gives an objective counterpart to reported function and fatigue. Across neurological, psychiatric, respiratory, pain and dermatology programmes actigraphy objectively quantifies sleep continuously, duration and distruption, providing an independent measure in addition to patient-reported and clinician-administered assessments. Continuous cardiac and respiratory signals add physiological and safety context in cardiovascular and respiratory studies, and remotely captured vital signs support monitoring between visits. Even highly specific behaviours can be measured: in atopic dermatitis, nocturnal scratch derived from wrist actigraphy has been validated against expert-annotated video, quantifying the one thing patients cannot reliably self-report, because it happens while they sleep (npj Digital Medicine, 2023).
What regulators already accept
The question sponsors ask first is whether a sensor measure can carry real regulatory weight. It can. Stride velocity, recorded by a wrist-worn device, became the first wearable-derived digital endpoint qualified by the EMA, initially as a secondary and, in 2023, as a primary efficacy endpoint in Duchenne muscular dystrophy. It was qualified as an endpoint in its own right, not as an accessory to a clinical scale, which is the strongest possible evidence that a well-constructed digital measure can meet the same evidentiary bar as an established assessment. Sensor-enhanced eCOA takes the next step. Rather than replacing the certified measure, it sets a continuous, objective view alongside it, so a programme keeps the endpoint regulators expect and gains the resolution a sensor provides. That pairing is an emerging discipline, and one Signant and Ametris are now unusually well placed to build.
And it is not only regulators who have moved. Across the industry, wearables have shifted from novelty to routine: sponsors are building activity, sleep and other sensor measures into protocols across therapeutic areas, and a digital endpoint is increasingly something a development team plans for rather than debates. Stride velocity is the landmark example, but it is no longer the exception. The organisations setting the pace now treat sensor data as part of how modern efficacy evidence is built, not as an experiment bolted on at the edges.
Where the pairing pays off
Where it earns its place depends on the phase. In early and mid-phase studies, a continuous measure can reveal the shape of a response, the turn toward benefit, or a dose separating from placebo, sooner and more sensitively than intermittent assessments. That matters commercially as much as scientifically. The stride-velocity programme, for instance, detected decline over shorter intervals than the six-minute walk test or the North Star Ambulatory Assessment, and a more sensitive measure can translate into a smaller sample size or a shorter study to observe the same effect. Earlier, clearer signal supports better go/no-go and dose decisions before a programme commits to a large confirmatory trial.
In confirmatory trials the role is different, and deliberately so. There the eCOA remains the primary and secondary endpoints, and the sensor is deployed as a pre-specified exploratory measure that corroborates them. Two independent methods pointing the same way make the efficacy story more robust for regulators and payers, and where a sensor and a diary point to complementary dimensions of benefit, that is a feature, not a flaw- each captures something the other cannot, and together they give a more complete picture than either alone.
Throughout, capture is passive and at home, so it adds evidence without adding burden and supports decentralised and hybrid designs, and it sits within the FDA's 2023 guidance on fit-for-purpose digital health technologies.
The choice was never eCOA or wearables. Keep the measure regulators trust, add an objective, continuous view of the same benefit, and put it where in the programme it does the most good.
None of this comes from the device alone. A cleared sensor is a starting point; the value lies in the endpoint it supports, and that endpoint has to be verified and validated for its context of use, with the evidence and documentation regulators expect, exactly as the stride-velocity programme showed. Turning continuous sensor streams into analysis-ready, fit-for-purpose measures, and defending them, is where Ametris' sensor science and Signant's measurement and regulatory expertise now sit under one roof.
The enhancement story
Sponsors no longer have to choose between the measure regulators trust and the resolution modern science can provide. Used where it fits, from early-phase signal detection to confirmatory corroboration, sensor-enhanced eCOA offers both: the validated endpoint a programme already reports, and an objective, continuous, at-home view of the same benefit. The result is richer, more complete evidence, earlier insight, and a stronger evidence package, achieved without disturbing the endpoints a programme depends on.
To explore where sensor-enhanced eCOA could strengthen a specific programme, from signal detection to submission, speak with Signant Health about the core Ametris digital health technologies.
Clinical examples are illustrative or drawn from published work. Sensor-derived measures are described as complementary or exploratory alongside validated eCOA, except where independently qualified. Stride velocity 95th centile was qualified by the EMA in Duchenne muscular dystrophy (secondary 2019; primary 2023) and has shown greater sensitivity to change than the six-minute walk test and the North Star Ambulatory Assessment. Nocturnal-scratch validation: npj Digital Medicine, 2023.
About the authors
Helen Brooker is a specialist in cognitive test development and aging, with over 18 years of experience in academic and clinical research. She leverages her expertise in neuropsychological assessment, clinical trial delivery, and digital health solutions as a Senior Product Manager at Signant, where she oversees the company's proprietary computerized cognitive test solution.
Marcela Roy, MA, ACC serves as Executive Director of Clinical Science & Medicine, bringing over 20 years of clinical and research expertise to her role. She provides strategic leadership across CNS and non-CNS therapeutic areas, with particular expertise in psychedelic research and central ratings data quality monitoring methodologies.
