OVERVIEW
Consistent airway inflammation measurement is critical in respiratory trials
Respiratory studies depend on objective biomarkers that can be collected consistently across sites and patient populations. FeNO measurement helps researchers quantify airway inflammation and complement traditional pulmonary function assessments when evaluating treatment effects or characterizing patient populations.
SOLUTION
One respiratory endpoint partner from protocol design through database lock
Sponsors often manage multiple vendors, disparate data streams and inconsistent site execution. Clario delivers a coordinated FeNO solution that combines devices, training, operational support and centralized data management within a single respiratory assessment ecosystem.
Design studies with FeNO in mind
Protocol consultation helps sponsors select appropriate FeNO approaches, optimize assessment schedules and support endpoint consistency.
Accelerate site
readiness
Configured devices, site onboarding and deployment support help drive consistent study execution worldwide.
Improve measurement consistency with training
Comprehensive training helps site personnel perform FeNO assessments according to study requirements.
Strengthen data
quality
Comprehensive training to help create consistent and regulatory ready FeNO data.
Connect respiratory endpoints
Integrate FeNO data alongside spirometry and other respiratory assessments for a more complete view of patient outcomes.
Support the regulatory process
Regulatory environment support to help you achieve fast study start-up with a variety of FeNO options.
A complete clinical trial solution
Clario delivers a fully integrated clinical trial solution that combines FeNO measurement with centralized data management, expert oversight, site support and regulatory-ready workflows.
Rather than managing multiple vendors and disconnected data streams, sponsors can work with a single respiratory endpoint partner from protocol design through database delivery. By integrating FeNO within a broader respiratory assessment strategy, Clario helps support consistent measurement collection, streamlined operations and high-quality data across global studies.
From data quality oversight to integrated respiratory assessments, these capabilities are designed to support reliable endpoints and efficient study execution:
Integrated FeNO data with quality control
FeNO measurements are integrated into a centralized clinical trial ecosystem, helping support data consistency, accessibility and oversight throughout the study lifecycle. FeNO results can be evaluated alongside other respiratory assessments, providing sponsors with a more complete view of treatment response and patient outcomes.
Quality control processes are designed to support reliable endpoint data and efficient study execution.
Capabilities include:
- FeNO repeatability checks to improve measurement reliability
- Outlier detection to identify potentially problematic data early
- Secure data transfer and centralized review workflows
- Regulatory-ready source documentation
Connect FeNO with a broader respiratory endpoint strategy
FeNO data is often most valuable when assessed alongside complementary respiratory endpoints. Clario combines FeNO assessments with spirometry and other respiratory measurements through coordinated operational workflows, centralized oversight and integrated data delivery.
This connected approach helps sponsors evaluate respiratory health through multiple objective measures while simplifying study management across endpoint providers.
Clinical workflows designed for trial integrity
Blinded data collection and review processes are built into study workflows across data capture, reporting and sponsor-facing systems.
Blinded FeNO data management is embedded across data capture, review, and reporting workflows, protecting study integrity while providing teams with the insights needed to monitor trial execution and data quality.
These controls help maintain protocol integrity while providing study teams with the visibility needed to effectively monitor trial progress and data quality.
Why FeNO matters in respiratory clinical trials
FeNO provides an objective, quantitative measure of airway inflammation that can add biological context to functional and patient-reported outcomes. Depending on the protocol and investigational therapy, FeNO may support:
- Participant selection
- Inflammatory phenotype characterization
- Longitudinal monitoring
- Pharmacodynamic assessment
- Exploratory responder analyses
FeNO can help sponsors form a more complete view of treatment response when evaluated alongside spirometry, symptoms, exacerbations, and other biomarkers.
Why sponsors choose Clario for their FeNO studies
Integrated respiratory endpoint expertise
Standardized data collection workflows
Integrated outlier check, repeatability check and full workflow control
Help desk support
Unified delivery across respiratory assessments
Related solutions
Site-Based Spirometry (FEV1, FVC, PEF, and more.)
Centralized, on-site pulmonary function testing for clinical trials.
Cough and Lung Sounds
Assessment of cough frequency, cough severity and other lung sounds such as crackles or rhonchi for clinical trials.
Virtual Home Spirometry
Remote spirometry testing for respiratory clinical trials
Learn more or speak with one our experts
Our team of clinical trial respiratory solution experts are always available to address questions about our respiratory solutions. Submit your contact information and we’ll be in touch shortly.
FAQs
What is FeNO assessment?
Fractional exhaled nitric oxide (FeNO) assessment is a non-invasive test that measures nitric oxide in exhaled breath. As a biomarker of eosinophilic airway inflammation, FeNO supports the evaluation and stratification of inflammatory phenotypes in respiratory clinical trials.
Why is FeNO measured in clinical trials?
FeNO (Fractional exhaled Nitric Oxide) is measured in clinical trials because it provides a non-invasive, objective indicator of airway inflammation. Elevated FeNO levels are often associated with type 2 (eosinophilic) inflammation, which plays a key role in asthma and certain other respiratory conditions.
In clinical research, FeNO testing helps investigators:
- Identify appropriate study participants who may have underlying airway inflammation
- Stratify patients into subgroups based on inflammatory characteristics
- Monitor changes in airway inflammation over time during treatment
- Evaluate the biological effects of investigational therapies, particularly those targeting inflammatory pathways
- Complement other clinical endpoints such as lung function tests, symptom assessments, and exacerbation rates
Because the test is quick, non-invasive, and repeatable, FeNO assessment can be performed at multiple study visits with minimal burden to participants. This helps researchers collect consistent data and gain deeper insights into treatment response throughout the course of a clinical trial.
Which types of clinical trials commonly use FeNO testing?
FeNO testing is most commonly used in respiratory clinical trials where airway inflammation plays an important role in disease progression, patient selection, or treatment response. Because FeNO provides a non-invasive and objective measure of eosinophilic airway inflammation, it has become an established biomarker in many respiratory research programs.
Asthma clinical trials are among the most common applications for FeNO assessment. Researchers use FeNO measurements to help identify patients with type 2 (eosinophilic) inflammatory asthma, characterize study populations, and evaluate how investigational therapies affect airway inflammation over time. FeNO data is often collected alongside lung function testing, symptom assessments, and exacerbation monitoring.
Severe asthma studies frequently incorporate FeNO testing to support the development of advanced treatments, including biologics and targeted therapies. In these trials, FeNO can help identify patients who may benefit from treatments aimed at specific inflammatory pathways and provide insight into biological response during treatment.
Pediatric asthma trials also commonly utilize FeNO assessments because the test is simple, quick, and non-invasive. Since the procedure only requires a controlled exhalation into an analyzer, it is well-suited for repeated assessments in children and adolescents participating in clinical research.
Beyond asthma, FeNO testing is increasingly used in studies involving eosinophilic airway diseases, where elevated nitric oxide levels may indicate underlying inflammatory activity. Researchers may use FeNO as a biomarker to better understand disease mechanisms, select appropriate participants, and monitor treatment effects.
Chronic cough studies may also include FeNO measurements to investigate the role of airway inflammation in persistent cough symptoms. In some research settings, FeNO can provide valuable information about inflammatory status and response to therapy.
In selected COPD clinical trials, FeNO testing may be used to identify inflammatory phenotypes within a broader patient population. Although FeNO is not used as extensively in COPD research as it is in asthma studies, it can provide useful supplemental information in trials evaluating inflammatory biomarkers and targeted treatments.
Finally, FeNO assessment plays an important role in the development of novel biologic, precision medicine, and anti-inflammatory therapies. As pharmaceutical companies continue to develop treatments that target specific inflammatory pathways, FeNO provides an objective biomarker that can help demonstrate biological activity, support patient stratification, and contribute to a more comprehensive understanding of treatment response.
Because FeNO testing is standardized, repeatable, and minimally burdensome for participants, it has become a valuable tool across a wide range of respiratory clinical trials, helping researchers generate high-quality data while improving their understanding of airway inflammation and therapeutic outcomes.
Why should FeNO data be blinded, and when is blinding recommended?
FeNO measurements can provide early insight into airway inflammation and treatment response. In many interventional clinical trials, blinding FeNO data is recommended when access to results could influence investigator decisions, patient management, site behavior, or study conduct.
By restricting access to treatment-related FeNO results, sponsors can help minimize operational bias, maintain protocol integrity, and ensure endpoint assessments remain objective. Blinded FeNO workflows are particularly important in randomized controlled studies where knowledge of biomarker trends could affect clinical decision-making or participant management. At the same time, centralized monitoring processes can continue to review data quality, compliance, and device performance without compromising the study blind.
Does FeNO replace spirometry or other lung function tests?
No. FeNO testing and spirometry measure different aspects of respiratory health and provide complementary information in clinical trials. While both assessments are valuable tools in respiratory research, they answer different clinical questions and are often used together to provide a more complete picture of a patient’s disease status and treatment response.
FeNO (Fractional exhaled Nitric Oxide) measures airway inflammation, specifically the presence of type 2 (eosinophilic) inflammatory activity within the airways. Elevated FeNO levels may indicate underlying inflammation that is commonly associated with certain forms of asthma and other inflammatory airway diseases. Because FeNO testing is non-invasive and can be performed repeatedly over the course of a study, it is often used as a biomarker to monitor changes in airway inflammation and evaluate the biological effects of investigational therapies.
Spirometry, on the other hand, measures lung function. It evaluates how much air a person can inhale and exhale, as well as how quickly air can be expelled from the lungs. Common spirometry endpoints such as Forced Expiratory Volume in One Second (FEV₁) and Forced Vital Capacity (FVC) help researchers assess airflow limitation, airway obstruction, and overall respiratory performance.
Importantly, airway inflammation and lung function do not always change in parallel. A participant may experience a reduction in airway inflammation, reflected by lower FeNO levels, before meaningful improvements are observed in spirometry results. Likewise, some patients may have relatively normal lung function measurements while still exhibiting elevated inflammatory activity within the airways. For this reason, relying on either assessment alone may not provide a complete understanding of disease activity or treatment effects.
In clinical trials, FeNO is often used alongside spirometry, symptom questionnaires, exacerbation assessments, biomarker testing, and other clinical endpoints. Together, these measurements help researchers evaluate both the biological and functional impact of a treatment. By combining FeNO and lung function testing, researchers can gain a more comprehensive understanding of respiratory disease mechanisms, patient response to therapy, and overall clinical outcomes.