FDA device marketing approval and clinical trial endpoint acceptability are different issues. Equating the two may confuse sponsors about risks involved.

For instance: "Since there are no cough counters approved by the FDA, does that mean their inclusion in a clinical trial is risky?"

The above-mentioned question is understandable, although it contains a category mistake. It treats U.S. device marketing authorization and acceptance of a measurement strategy in a drug-development program as the same regulatory decision. They are not.

CDRH asks whether a device can be marketed for an intended use

The Center for Devices and Radiological Health (CDRH) oversees medical devices. It reviews 510(k) submissions, De Novo requests and premarket approval applications. If a cough monitor is marketed to clinicians or patients to inform diagnosis, management or treatment decisions, CDRH evaluates whether the product is safe and effective for that labeled intended use.

CDER asks whether an endpoint can support a drug program

The Center for Drug Evaluation and Research (CDER) reviews drugs and the Center for Biologics Evaluation and Research (CBER) reviews biologics and approves drugs for use. In a CDER/CBER-led development program, the relevant review division evaluates whether the proposed endpoint - and the technology used to measure it - is fit for purpose for that drug, indication, population and trial design. CDER may consult CDRH on device questions, but the program-specific evidentiary decision sits with the center responsible for the investigational medical product.

Put plainly: CDRH clearance is neither necessary nor sufficient for CDER to accept a cough monitor as a trial endpoint. The two run on independent tracks.

Why clearance is not a prerequisite

FDA's 2023 guidance on digital health technologies is explicit: a DHT that meets the definition of a device may still be used only for data acquisition in a clinical investigation without first obtaining marketing authorization, provided the investigation complies with applicable requirements under 21 CFR Part 812. For many nonsignificant-risk DHTs, a separate IDE application is not required when the abbreviated IDE requirements are met.

That does not mean that the instrument is unregulated or that no evidence is required. The sponsor still needs to address risk, verification, validation, usability, data integrity, version control and missing data. The point is that a 510(k) clearance or De Novo grant is not a gate that every research measurement tool must pass before it can be used in a drug trial.

The reverse is also true. Marketing authorization is not automatic endpoint acceptance. A clearance may cover recording or storing audio, for example, without covering automated cough-event detection. Even a clearance that explicitly covered cough counting would not, by itself, establish that the measure is appropriate for every indication, population, time window or estimand. Clearance is granted device by device, for a specified intended use; it does not travel. The endpoint question is one every cough counter answers on its own evidence, cleared or not.

The fit-for-purpose question has two parts:

• First is the measurement question: can the system capture cough reliably under the conditions of the proposed study? The evidence may need to cover sensor and algorithm performance, test-retest reliability, the target population, real-world environments, day and night use, data flow, usability, missingness and software change control.

• Second is the endpoint question: is objective cough frequency the right way to demonstrate benefit for this drug and indication? That includes the endpoint definition, monitoring window, statistical treatment, clinical meaningfulness and relationship to how patients feel or function. The technology provider can supply the measurement evidence. The sponsor owns the scientific argument for the endpoint within the development program.

A real-world example of the distinction

In June 2026, KYORIN announced the start of a pivotal study of KRP-DC125, a digital therapeutic for chronic cough that integrates Hyfe's cough-monitoring tools. Hyfe separately announced that Japan's Pharmaceuticals and Medical Devices Agency had agreed to the CoughMonitor Suite as the primary-endpoint measurement tool for that study.

This is a PMDA example, not a CDER decision, and it says nothing by itself about U.S. device marketing authorization. It does, however, demonstrate the structural point: a drug regulator can assess a research measurement tool for a pivotal endpoint on the strength of program-specific evidence without treating device marketing authorization as a prerequisite.

None of this makes device development irrelevant. Verification, analytical and clinical validation, human factors, quality systems and change control all contribute evidence a drug regulator may want to see. But clearance status itself is not what wins endpoint acceptance, and it should not be treated as a step toward it.

Ask the right regulatory regulators the right question

For drug developers, CDER or CBER are the regulators and for them the useful question is not whether a cough monitor is cleared. It is whether the measurement tool and the endpoint are fit for purpose for this drug, this indication and this trial. The technology provider answers for the measurement; the sponsor answers for the endpoint. ______________________________

References and regulatory sources

1. U.S. FDA. Digital Health Technologies for Remote Data Acquisition in Clinical Investigations (December 2023).

2. Bakker JP, Izmailova ES, Clement A, et al. Regulatory Pathways for Qualification and Acceptance of Digital Health Technology-Derived Clinical Trial Endpoints. Clinical Pharmacology & Therapeutics. DOI: 10.1002/cpt.3398.

3. KYORIN Pharmaceutical Co., Ltd. Initiation of a Confirmatory Study for KRP-DC125 (11 June 2026).

4. Hyfe, Inc. Hyfe Cough Monitoring to be Primary Endpoint in Pivotal Clinical Trial (15 June 2026).