Findings
The rapid advancement of sensor technology and connectivity has enabled high-frequency, longitudinal monitoring of physiological processes, yet the infrastructure for large-scale deployment remains resource-intensive. Current challenges include a lack of standardized terminology for digital decision-making tools and significant variability in environmental factors that affect sensor performance. Proprietary algorithms and device-specific barriers often hinder the verification and validation processes necessary for regulatory approval. Additionally, there is a distinct gap between granular digital features and their clinical relevance or meaningfulness to patients. Ethical concerns are emerging around data management, patient anxiety in psychiatric contexts, and the responsibility for addressing adverse events detected by remote monitoring.

Recommendations
Stakeholders should develop consensus-driven frameworks for standardized device performance reporting and environmental testing to streamline evaluations for specific contexts of use. The community should adopt a modular approach to data standards that bins requirements by concept of interest and disease-specific needs. Collaborative efforts between patients and developers are essential to bridge the gap between technical metrics and meaningful aspects of health. It is recommended to implement ""bring-your-own-device"" (BYOD) frameworks that ensure data reliability while supporting the inevitable evolution of technology during long-term studies. Researchers and clinicians must be trained in the ethical, legal, and social implications of digital health technology use, particularly regarding data privacy and the management of remote-detected safety signals.

Regulatory Considerations
Digital health technologies used to collect endpoints must meet high evidentiary requirements for validation, with complexity increasing when multiple sensors or complex software are bundled. Regulatory agencies like the FDA and EMA have established pathways for the qualification of drug development tools, including biomarkers and clinical outcome assessments. Integration of new draft guidance on remote health monitoring with existing regulatory workflows is necessary to reduce uncertainty in trial evaluations. While many digital health technologies do not qualify as medical devices unless they have a specific medical purpose, synergies between device risk assessments and drug trial data integrity frameworks should be explored. Early engagement with regulators remains a critical step for obtaining feedback on novel digital endpoints and ensuring the suitability of evidentiary support.

Findings
The traditional process of evaluating biomarkers within the context of a single drug development program is inefficient and creates uncertainty for sponsors. This case-by-case approach leads to redundant efforts, slows down the development of novel therapies, and hinders the broad adoption of promising scientific tools. There is a clear need for a centralized, collaborative pathway to formally validate biomarkers, which can de-risk drug development, encourage innovation, and make the process more predictable and cost-effective for all stakeholders.

Recommendations
Drug developers, academic researchers, and other stakeholders should proactively engage with the FDA through the formal Biomarker Qualification Program to validate biomarkers for specific contexts of use. It is recommended to form public-private partnerships and other collaborations to pool resources and data, which strengthens the evidence package for a biomarker's utility. Developers should use the qualification process to establish a biomarker's value early, making it a publicly available and reliable tool that can accelerate the development of multiple drug products.

Regulatory Considerations
The Biomarker Qualification Program provides a distinct regulatory pathway for establishing a biomarker's validity for a specific Context of Use (COU), separate from an individual Investigational New Drug (IND) or New Drug Application (NDA). The process involves a three-stage submission and review cycle: the Letter of Intent, the Qualification Plan, and the Full Qualification Package. Once qualified, a biomarker is publicly listed and can be incorporated into multiple drug development programs without the need for sponsors to re-submit and re-justify the validation data for that specific COU, streamlining subsequent regulatory reviews.

Findings
Establishing cross-sector consortia does not guarantee success without a unified objective and stakeholder buy-in. A neutral, independent facilitator is a key element for successful governance in many collaborative platforms. Many consortia lack consistent methods for storing critical data, meeting minutes, and regulatory briefing packages, which creates barriers after project completion. Regulatory success depends heavily on the early development of a strategy that defines the necessary evidence to validate innovative methodologies. Successful examples include the qualification of biomarkers for polycystic kidney disease and type 1 diabetes, as well as imaging measures for Alzheimer’s disease.

Recommendations
Consortium members should develop an initial regulatory strategy during the project scoping and planning phases. Teams must explicitly define the context of use for any proposed tool to articulate exactly what decisions the output will inform. A robust data strategy should be implemented early, including formal agreements for data use, standardization, and sharing that remain in place in perpetuity. Consortia must prioritize sustainability plans to ensure data and active databases remain available for research and regulatory use after funding expires. Projects should integrate regulatory science expertise from the start to cover both EU and US frameworks.

Regulatory Considerations
Regulators require individual patient-level data that is fully curated, standardized, and presented through formal submissions like qualification applications. Formal regulatory endorsement ensures a tool can be trusted for consistent interpretation in drug development and marketing authorization evaluations. Early engagement with agencies such as the FDA and EMA is essential to gain feedback on novel methodologies and align study designs with regulatory expectations. Specific pathways like the EMA Qualification of Novel Methodologies and the FDA Qualification Process for Drug Development Tools should be utilized. Regulatory qualification may require ongoing access to databases to support the long-term use of the methodology.

Key Principles (Findings)
The central principle of the DDT Qualification Programs is to create a formal pathway for the FDA to conclude that a specific tool is well-suited for a particular Context of Use (COU) in drug development. A key finding, as reflected in the program's design, is that qualification de-risks drug development by allowing a tool to be used in any regulatory submission for its qualified COU without needing to be re-validated each time. The program is designed to foster stakeholder collaboration, encouraging the development of tools that can benefit the entire research community, thereby reducing the burden on individual sponsors.

Program Activities (Recommendations)
The structure of the DDT programs serves as a series of recommendations for tool developers:
Engage Early and Collaboratively: The programs are designed to provide a framework for early and ongoing scientific collaboration with the FDA to facilitate the development of new tools.
Follow a Staged Process: Developers are guided through a multi-stage process, typically involving a Letter of Intent, a Qualification Plan, and a Full Qualification Package, to systematically build the evidence needed for qualification.
Seek Public Qualification: The ultimate recommendation is to achieve public qualification for a DDT, which makes the tool available for broad use and integrates it into the regulatory review process, expediting future drug development.

Regulatory Considerations
The DDT Qualification Programs are a formal regulatory framework established under the 21st Century Cures Act. A "qualified" DDT has a specific regulatory status; it can be relied upon to have a specific interpretation and application in drug development and regulatory review for its stated Context of Use (COU). This qualification is publicly available and allows the tool to be included in Investigational New Drug (IND), New Drug Application (NDA), or Biologics License Application (BLA) submissions without the FDA needing to reconsider its suitability. This creates a more efficient and predictable regulatory compliance pathway for sponsors who use the qualified tool.

Findings
The database provides a transparent and accessible way for the public to track the progress of various Drug Development Tools (DDTs) through the FDA's qualification pipeline. This includes biomarkers, clinical outcome assessments, and animal models. The information available, such as submission status and supporting documentation, offers insight into the types of tools being developed and the evidence required for their qualification. The platform reveals that a wide range of tools are in development across numerous therapeutic areas, highlighting active areas of research and innovation in drug development.

Recommendations
Stakeholders in the drug development ecosystem are encouraged to utilize this database to inform their research and development strategies. By reviewing the status of existing DDT submissions, sponsors can identify opportunities for collaboration, avoid duplicative efforts, and better understand the evidentiary requirements for tool qualification. Prospective tool developers should use the database to learn from successful submissions and to align their own development plans with FDA expectations.

Regulatory Considerations
This database is a direct implementation of the transparency provisions of the 21st Century Cures Act. The public availability of this information is intended to foster trust and collaboration in the DDT qualification process. By providing a clear view of the regulatory journey of various tools, the FDA aims to standardize the qualification process and encourage the development and use of novel, validated tools in drug development. Users of the database should be aware that the information reflects the status of a DDT at a particular point in time and that the qualification process is an iterative one.

Findings
Clinically Acceptable Performance: A clinical study demonstrated that the weekly AFib burden estimates from the Apple AFib History Feature were in close agreement with a reference ECG patch, with an average difference of just 0.67%. The vast majority of measurements had paired differences within ±10% of the reference device.
Generalizable Across Subgroups: The device's accuracy was similar across various subgroups, including different sexes, races, ages, and skin tones.
Performance Post-Ablation is Uncertain: In a small subgroup of patients with a prior cardiac ablation, the device's performance, while still strong, showed slightly more variability and exceeded a pre-specified acceptance criterion. The study was not designed or powered to demonstrate equivalent performance in this specific group.
Technical Limitations Exist: The feature only provides a retrospective weekly estimate and does not give specific timestamps or durations of AFib episodes. It also does not detect other atrial tachyarrhythmias, like atrial flutter.

Recommendations
Appropriate Use: The document implicitly recommends using the tool precisely within its qualified context of use—as a secondary, not primary, endpoint for comparing AFib burden between study arms in cardiac ablation device trials.
Supplemental Data Collection: For studies involving patients who have had a prior ablation, it would be beneficial to assess the tool alongside other methods of determining AFib burden to better characterize its performance in this population.
Define Study-Specific Endpoints: Investigators using the tool are responsible for defining and justifying their specific study designs and what constitutes a clinically significant reduction in AFib burden.

Regulatory Considerations
MDDT Qualification: The Apple AFib History Feature is officially qualified by the FDA as a Medical Device Development Tool (MDDT), which reduces the burden on device developers, as they no longer need to independently justify its methodology for collecting weekly AFib burden estimates in their clinical studies.
Secondary Endpoint Only: A key limitation for its regulatory use is its qualification only as a secondary endpoint. It cannot, by itself, be used to evaluate the primary safety and effectiveness of cardiac ablation devices. This is partly because FDA typically requires the inclusion of any atrial tachyarrhythmia (not just AFib) for defining ablation success in pivotal studies.
Not a Replacement for Primary Endpoints: The tool's utility is intended to provide supplemental data and help better understand post-treatment AFib burden; it is not meant to replace more clinically well-defined primary endpoints.

Findings
The development and evaluation of medical devices require scientifically plausible and reliable tools for collecting data to support regulatory submissions. A lack of standardized, pre-vetted tools can lead to inefficiencies and unpredictability in the device development and review process. The qualification of development tools can be applied across a wide range of device areas, including cardiovascular, neurology, imaging, and cybersecurity. The evidence required for tool qualification must be robust enough to support its intended context of use.

Recommendations
Tool developers, medical device sponsors, research organizations, and academic institutions are encouraged to voluntarily submit proposals to the MDDT program to qualify their tools. Submissions should include a detailed description of the tool, a clearly defined context of use (COU), specific performance criteria, and a comprehensive plan for collecting evidence to validate the tool's performance and scientific plausibility. Collaboration in developing tools and supporting evidence is recommended to pool resources and increase the acceptance of qualified tools.

Regulatory Considerations
The MDDT program is a formal regulatory mechanism for the FDA to qualify tools that can be used to support assessments of medical device safety, effectiveness, or performance. Once a tool is qualified for a specific context of use, the FDA accepts assessments from that tool in support of regulatory submissions without needing to re-evaluate the tool's suitability. The program recognizes four main categories of tools: Non-clinical Assessment Models (NAM), Biomarker Tests (BT), Clinical Outcome Assessments (COA), and an "Other" category for tools that do not fit the primary classifications.

Findings
Sleep disturbances are common across multiple therapeutic areas, making standardized digital measures essential for cross-condition research.
Measurement accuracy varies depending on sensor placement, algorithms, and contextual factors such as sleep environment.
While home-based digital sleep tracking improves accessibility, challenges remain in ensuring consistency with clinical polysomnography.
Digital measures of sleep provide new opportunities for continuous and longitudinal monitoring, but standardization in data collection and interpretation is needed.
Stakeholders, including regulatory agencies, increasingly recognize digital sleep biomarkers, but additional validation is required to ensure widespread adoption.

Recommendations
Researchers and clinicians should integrate core digital sleep measures into study designs to improve data comparability across trials and clinical contexts.
Algorithm transparency and validation protocols should be established to enhance the accuracy of digital sleep monitoring tools.
Regulatory engagement should be prioritized early in the development process to ensure that digital sleep measures meet evidentiary standards.
Multi-stakeholder collaboration, including patient and care partner input, is essential to ensure sleep measures reflect meaningful aspects of health.
Further research is needed to refine wearable and sensor-based technologies to improve real-world applicability and clinical utility of digital sleep biomarkers.

Regulatory Considerations
The FDA and other regulatory bodies increasingly acknowledge sleep measures as potential clinical endpoints, but clear validation frameworks are necessary.
Digital sleep measures should align with industry standards such as HL7 to ensure interoperability and data integrity.
Data privacy and security regulations must be followed, particularly for continuous sleep monitoring in real-world settings.
Post-market validation and real-world evidence generation are critical to support regulatory acceptance of digital sleep biomarkers.
Developers must document the derivation of sleep measures, including algorithmic processing and sensor accuracy, to meet regulatory review requirements.

Findings
The field lacks a centralized, standardized database of validated digital health technologies, making it difficult for researchers and clinicians to select appropriate tools.
Non-wearable sensors and software applications are the most common types of DHTs, with 83% of ambient technologies categorized as software or applications.
Most DHTs focus on mild cognitive impairment (MCI) and early Alzheimer’s disease, with fewer technologies validated for moderate or severe dementia stages.
Uneven Distribution of Dementia Subtypes – The review identified a gap in DHT validation for frontotemporal dementia (FTD) and Lewy Body dementia, with Alzheimer’s disease being the predominant focus.

Recommendations
Expand and maintain an open-access database of validated DHTs to improve accessibility and standardization.
Increase research on digital measures applicable to moderate and severe stages of dementia, as well as non-Alzheimer’s dementias.
Promote integration of wearable, ambient, and cognitive assessment tools to generate comprehensive digital phenotypes of patients.
Follow clear guidelines for analytical and clinical validation of DHTs to improve regulatory acceptance and research applicability.
Conduct more usability and feasibility assessments, especially for populations with cognitive decline, to ensure DHTs are accessible and effective in real-world settings.

Findings
There is a lack of systematic approaches to guide the processes of collecting, interpreting, analyzing, and translating health data from wearables into digital biomarkers.
Most wearables have fixed measurement capabilities, limiting their translation to digital biomarkers.
Current guidance lacks study design and conduct elements that involve all stakeholders in an iterative approach for implementing digital biomarkers in practice.
Researchers and health professionals often rely on limited guidance for using wearable data in clinical practice and chronic disease management.

Recommendations
Implement the DACIA framework to provide interdisciplinary guidance on using wearable sensor data for digital biomarker development.
Focus on participant needs as a crucial factor for study success, applicable to both short and long-duration studies.
Involve relevant stakeholders in each key step of the DACIA framework in an iterative manner.
Apply the DACIA framework to explore digital biomarkers using various devices or signal measurements.
Reduce participant burden through support and continuous feedback.

Regulatory Considerations
Not mentioned

Findings
Only a small number of novel digital measures have matured into regulatory qualification or efficacy endpoints.
Demonstrating that digital measures are meaningful to patients is a key challenge.
There is resistance from sponsors due to uncertainty about the value of DHT-derived endpoints in regulatory discussions.
Patient experiences are highly heterogeneous, making it difficult to generalize meaningful aspects of health.
Challenges exist in defining clinical significance and classifying digital measures as COAs vs biomarkers.

Recommendations
Engage patients and caregivers in facilitated discussions to incorporate their voices.
Determine the best method for gathering patient input on a case-by-case basis.
Engage patients to inform evidence needs, implementation, and value delivery.
Return summarized health data to participants to motivate and encourage communication with clinicians.

Regulatory Considerations
Understand the FDA's recent guidance on patient engagement in drug development.
Recognize the shift in evidence rigor required by the FDA for demonstrating meaningfulness.
Provide evidence that DHTs are usable, acceptable, and clinically relevant.
Utilize early engagement channels like CPIM and pre-LOI programs offered by the FDA.

Findings
There is a lack of alignment in concepts, definitions, and terminology related to digital health technologies, which hinders global drug development programs.
Different regulatory agencies interpret common terms like "monitoring" differently, leading to confusion and inconsistency.
The classification of digital measures impacts evidentiary requirements and regulatory acceptance, but detailed guidance on these requirements is lacking.

Recommendations
Align terminology and definitions across stakeholders to ensure consistency in understanding and communication.
Reuse existing terms where possible to avoid unnecessary complexity.
Focus on what is measured rather than how it is measured to streamline regulatory processes.
Encourage companies and regulators to reflect on and adopt a common lexicon within their organizations.
Move quickly to address critical questions about evidence needed for validation of digital measures.

Regulatory Considerations
Regulatory authorities should apply consistent standards for all endpoints, regardless of data acquisition methods.
The classification of DHTs as medical devices or not will impact their regulatory pathway and requirements.
There is a need for dialogue with regulators to clarify source data requirements for data acquired by DHTs.