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

6,771

Recruiting Now

6,771

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

Breast Cancer (110) Stroke (104) Obesity (80) Cancer (65) Heart Failure (63) Prostate Cancer (53) Lung Cancer (52) Healthy (51) Depression (49) Hypertension (47)

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

NCT07402122 N/A

Registry for Duchenne and Becker Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD)

Austria, Germany

Dr. Andreas Ziegler

NCT07860697 N/A

Association of Subcutaneous Fat Index, Paraspinal Muscle Characteristics, and Fa...

Chronic Low Back Pain

Turkey (Türkiye)

Marmara University

NCT06626360 N/A

Screening for Malnutrition in Obese Patients

Overweight and Obese Adults

HAN University of Applied Scie

NCT07246382 N/A

Evaluation of a Customizable Antibiotic Stewardship Program Tailored to French N...

Antibacterial Agents

University of Lorraine

NCT07496424 N/A

Manual- VS Auto-Strain

Transesophageal Echocardiography

NCT07101770 N/A

A Prediction Model in Pregnant Women With Aplastic Anemia

Aplastic Anemia

Peking University People's Hos

NCT06800469 N/A

Gut Microbiota Analysis in Patients Undergoing Duodencephalopancreasectomy for P...

Pancreatic Cancer, Adult

IRCCS Azienda Ospedaliero-Univ

NCT06544941 N/A

Improving Maternal Sleep and Mental Health

Postpartum Depression

University of Colorado, Colora

NCT07227441 N/A

Chronic Infections and Inflammation in ME/CFS: An Observational Study

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

University of California, San

NCT06907654 N/A

Couples' Affect in Relationships Study

Depression Disorders

University of Wisconsin, Madis

NCT03225794 N/A

Simian Foamy Virus Transmission to Humans

Simian Foamy Virus Infection (Disorder)

Institut Pasteur

NCT06532994 N/A

Predictive Algorithms for Critical Rehabilitation Outcomes

Wuhan University

NCT06670456 N/A

Prospective Cohort of Patients With Intracerebral Hemorrhage

NCT07778797 N/A

Guangke Lenses in Congenital Cataract

Congenital Cataract

Eye & ENT Hospital of Fudan Un

NCT00230620 N/A

Molecular Studies on Hereditary Haemorrhagic Telangiectasia Families

Telangiectasia, Hereditary Hemorrhagic

Imperial College London

NCT06459024 N/A

Master Framework For Relapse or Refractory Acute Myeloid Leukemia

Acute Myeloid Leukemia, in Relapse

Germany, Italy, Jordan

Istituto Romagnolo per lo Stud

NCT06835959 N/A

Moms@Home: A Storytelling-based Mobile Health Intervention to Improve Blood Pres...

Hypertension in Pregnancy

University of Massachusetts, W

NCT07635823 N/A

Adaptive DBS for PD

Parkinson Disease(PD)

Beijing Pins Medical Co., Ltd

NCT07397559 N/A

Spatiotemporal tSCS in Spinal Cord Injury

Spinal Cord Injuries (SCI)

Washington University School o

NCT07407959 N/A

Screening and Staging of Benign vs Malignant Pelvic Abnormalities

Endometrial Carcinoma

NCT07001696 N/A

Combining Chest X-Ray and Arterial Blood Gas Findings to Predict Need for Mechan...

Respiratory Failure

Zagazig University

NCT06727162 N/A

The Value of CEUS in Assessing the Response of Cervical Lymph Nodes After NACI f...

Head and Neck Squamous Cell Carcinoma

Sun Yat-Sen Memorial Hospital

NCT07514962 N/A

Minimally Invasive Coronary Artery Bypass Supported by Cangrelor

Coronary Artery Disease

Cardiocentro Ticino

NCT07062003 N/A

Minibeam Radiation Therapy With Tungsten Slit Collimator for the Treatment of Re...

Metastatic Malignant Skin Neoplasm

NCT06681142 N/A

Pharmacist-physiotherapist Collaborative Management for Early Knee Osteoarthriti...

Osteoarthritis (OA) of the Knee

University of Alberta

Page 11 of 271 — 6,771 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