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

6,814

Recruiting Now

6,814

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

Breast Cancer (108) Stroke (98) Cancer (89) Heart Failure (64) Obesity (61) Prostate Cancer (56) Healthy (54) Anxiety (51) Hypertension (48) Coronary Artery Disease (48)

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

NCT07464093 N/A

STABLE Pilates for Hypermobility

Ehlers-Danlos Syndrome (EDS)

Brigham and Women's Hospital

NCT06771193 N/A

Study on Disease Characteristics and Treatment in Locally Advanced or Recurrent ...

Cervical Cancer

MSD Italia S.r.l.

NCT06886204 N/A

Youth Participatory Action Research to Prevent Community Violence Among Black Yo...

Community Violence

Emory University

NCT06844604 N/A

Carbon Footprint Assessment for Robotic, Laparoscopic and Open Colorectal Operat...

Colorectal Operations

University Hospital, Basel, Sw

NCT04733404 N/A

Safety and Effectiveness Study of Dragonfly System for Functional Mitral Regurgi...

Mitral Regurgitation Functional

Hangzhou Valgen Medtech Co., L

NCT03583684 N/A

Neuroimaging Predictors of Improvement to Pivotal Response Treatment (PRT) in Yo...

Autism Spectrum Disorder

Stanford University

NCT04640584 N/A

C-Brace Prospective Registry

United States, Australia, Germany

Otto Bock Healthcare Products

NCT06915584 N/A

Drug Management in Heart Failure

IRCCS San Raffaele Roma

NCT07113184 N/A

Randomized a Clinical Trial With Medical Device in Acute Ischemic Stroke

Acute Ischemic Stroke

Instituto de Investigación Mar

NCT07006233 N/A

A Novel Approach to Manage Symptoms of Narcolepsy and Idiopathic Hypersomnia

Idiopathic Hypersomnia

University of Sydney

NCT06956833 N/A

Immersive Virtual Reality Simulation-Effects of Self-Guided Versus Facilitator-G...

Virtual Reality Simulation

Copenhagen University Hospital

NCT04664933 N/A

Intra-arterial Neuroprotective Strategy for Ischemic STroke Patients With Endova...

Stroke, Ischemic

NCT06591533 N/A

The Effect of Music Therapy on Vital Signs and Heart Rate Variability of Pediatr...

Respiratory Failure

Claudia Aristizábal

NCT07510984 N/A

Symptoms and Quality of Life in Patients With Heterotopic Gastric Mucosa (HGM)

Heterotopic Gastric Mucosa of the Proximal Esophagus

Knappschaft Kliniken GmbH

NCT05702281 N/A

Evaluation of the Safety and Efficacy of the ReLARC Inserter During the Insertio...

University Hospital, Ghent

NCT06800430 N/A

Graft Failure and Consequences of Coronary Artery Bypass Graft Surgery

Coronary Artery Bypass

University of Edinburgh

NCT07281092 N/A

Comparative Efficacy of Organizational Skills Training (OST) and Mindfulness-Bas...

Seattle Children's Hospital

NCT05956236 N/A

Hip Prospective Study

Hip Arthropathy

Societe dEtude, de Recherche e

NCT04671511 N/A

Targeted Axillary Dissection (TAD) in Early-stage Node Positive Breast Cancer

Breast Cancer Female

Jewish General Hospital

NCT05606536 N/A

The Impact of Intra-operative Fluid Infusion Rate on Microcirculation

University Hospital Hradec Kra

NCT07875036 N/A

Comparative Effects of Coherent Breathing and Regular Paced Breathing on Dyspnea...

Pulmonary Disease, Chronic Obstructive (COPD)

Foundation University Islamaba

NCT06082687 N/A

De-identified Human Tissue Project

University of Central Florida

NCT06270121 N/A

Development of a Healthcare Service Platform for Successful Aging

Depression in Old Age

NCT07197814 N/A

Evaluation of the Tolerance of a New Formula Based on Hydrolyzed Rice Proteins i...

IgE-Mediated Cow Milk Allergy

Health and Happiness Research

NCT07594821 N/A

MeDe Study: Comparing Median Nerve Decompression at the Carpal Tunnel Alone Vers...

Carpal Tunnel Syndrome (CTS)

Maasstad Hospital

Page 4 of 273 — 6,814 trials total

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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: November 2026 · Data Methodology