Clinical Trials / Browse by Phase / N/A (Early Phase / Not Applicable)

Browse by Phase

N/A (Early Phase / Not Applicable) Clinical Trials

Browse currently recruiting N/A (Early Phase / Not Applicable) clinical trials registered on ClinicalTrials.gov.

Total Trials

6,827

Recruiting Now

6,827

Top Conditions in N/A (Early Phase / Not Applicable)

Stroke (111) Breast Cancer (103) Cancer (89) Heart Failure (75) Obesity (70) Anxiety (58) Lung Cancer (57) Prostate Cancer (57) Depression (54) Coronary Artery Disease (50)

Frequently Asked Questions — N/A (Early Phase / Not Applicable) Trials

What does "N/A" mean for a clinical trial phase?

"N/A" or "Not Applicable" in the phase field indicates the trial does not follow the traditional Phase 1–4 drug development pathway. This applies to observational studies, epidemiological research, behavioral interventions, device studies, or exploratory work not yet assigned a formal phase. These studies are still registered on ClinicalTrials.gov and follow IRB-approved protocols.

Are N/A phase trials safe to participate in?

N/A phase trials encompass a wide range of study types, many involving minimal risk—such as observational studies, questionnaire-based research, or registry enrollment. Some may involve investigational devices or early-stage interventions. Review the trial's protocol, risks and benefits section, and informed consent documents carefully before enrolling. All ClinicalTrials.gov-registered studies must comply with applicable safety oversight requirements.

How do I find N/A phase trials for my condition?

Browse ClinicalMetric by condition to find all trials—regardless of phase—that are recruiting for a specific disease. Many N/A phase trials are observational or behavioral studies with fewer eligibility restrictions than phase-designated drug trials, making them more accessible to a broader range of participants.

Active N/A (Early Phase / Not Applicable) Studies

NCT06744660 N/A

Clinical Validation of the Aptitude Medical Systems Metrix COVID-19 Test

Aptitude Medical Systems

NCT04442724 N/A

Bladder Fiducial Markers and Multiparametric-MRI (Mp-MRI) to Optimize Bladder Ch...

Cedars-Sinai Medical Center

NCT06418282 N/A

Clinical Study to Evaluate the Effectiveness and Health Economics of a Novel Por...

Phlebolymphedema

Koya Medical, Inc.

NCT06764082 N/A

Nutritional Intervention for Biliary Atresia

Nutrition Disorder, Infant

Tongji Hospital

NCT07081724 N/A

"Opt-In" Early Intervention Program for Children Waiting to Receive an Autism Di...

Drexel University

NCT07105423 N/A

Mindful Eating and Sustainability

Sustainable Food Consumption

Turkey (Türkiye)

Atılım University

NCT07183423 N/A

Novel Skin Barrier Product Versus Petrolatum for Skin Barrier Dysfunction

Makati Medical Center

NCT05389878 N/A

Implementation of a Registry for Patients With Stroke

Fondazione Don Carlo Gnocchi O

NCT06906185 N/A

Adaptation and Examination of a Trauma-informed Intervention for Pregnant Vetera...

Trauma-related Mental Health Symptoms

VA Office of Research and Deve

NCT03487185 N/A

Continuous Positive Airway Pressure (CPAP) for Sleep Apnea in Pregnancy

Obstructive Sleep Apnea of Adult

The George Washington Universi

NCT05717985 N/A

Evaluation of De-epithelized Connective Tissue Grafts and Modified Combined Appr...

Gingival Recession

National University of Malaysi

NCT06155643 N/A

EKO SENSORA: Detecting Clinically Significant Murmurs

Corewell Health South

NCT04759443 N/A

Detection of Small Fiber Neuropathy Using Skin Properties

Small Fiber Neuropathy

Brigham and Women's Hospital

NCT07316543 N/A

Cognitive Rehabilitation for Veterans With PNES

Psychogenic Nonepileptic Seizures (PNES)

VA Office of Research and Deve

NCT04255615 N/A

Use of Artificial Intelligence for Clinical Assessment of Assisted Reproductive ...

Weill Medical College of Corne

NCT06931535 N/A

Remote Ischemic Conditioning for Acute Moderate Posterior Ischemic Stroke

Ischemic Stroke

General Hospital of Shenyang M

NCT06044935 N/A

Effect of Nicotinamide Riboside on Ketosis, Fat Oxidation & Metabolic Rate

National Institute of Diabetes

NCT07213908 N/A

Comparing Two School-Based Sleep Health Interventions To Promote Sleep Quality i...

Children's Hospital Los Angele

NCT06964308 N/A

Thoracoscopic Pleural Biopsy in Sohag University Hospital

Pleural Diseases

Sohag University

NCT05726825 N/A

Efficacy of Add-on Plasma Exchange As an Adjunctive Strategy Against Septic Shoc...

Austria, Germany, Switzerland

Hannover Medical School

NCT07504276 N/A

Tele-Rehabilitation vs Conventional Rehabilitation for Cognitive Improvement in ...

Riphah International Universit

NCT00912717 N/A

Pancreatic Adenocarcinoma Gene Environment Risk Study

Pancreatic Cancer

University of Pittsburgh

NCT05890417 N/A

Evolution of Sexual Life Quality of Women With POI Before and After Introduction...

Premature Ovarian Failure

University Hospital, Bordeaux

NCT06494540 N/A

NIS to Examine the Effectiveness of TDC in Patients With Metastatic Non-squamous...

Non-squamous Metastatic Non-Small-Cell Lung Carcinoma

NCT05789940 N/A

Hysteroscopy vs. Endouterine Aspiration in the Management of Trophoblastic Reten...

University Hospital, Montpelli

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer · Last Reviewed: April 2026 · Data Methodology