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

6,885

Recruiting Now

6,885

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

Stroke (113) Breast Cancer (104) Cancer (79) Obesity (68) Prostate Cancer (59) Coronary Artery Disease (51) Heart Failure (50) Cardiovascular Diseases (49) Lung Cancer (49) Healthy (49)

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

NCT07627178 N/A

A Prospective Comparative Study Evaluating the Safety and Efficacy of Transureth...

Benign Prostatic Hyperplasia (BPH)

Tanta University

NCT06387485 N/A

A Study to Evaluate the Utilization of 3D Printed Models in Pre-Operative Planni...

Ricoh USA, Inc.

NCT04284943 N/A

Surgical TreAtment for Obesity Related Disease and Onco-Metabolic Surgery

Korea University Anam Hospital

NCT05963815 N/A

The Spine PROMCO Study

Lumbar Disc Herniation

Park Medical centrum

NCT06600815 N/A

Analgesic Efficacy of Preemptive Stepwise Infiltration Anesthesia for Perioperat...

Total Knee Arthroplasty

First Affiliated Hospital of F

NCT07129915 N/A

Nudge-Based Shared Decision Making and Self-Management in Type 2 Diabetes: A Ran...

Diabetes Mellitus, Type 2

NCT06529835 N/A

A Comparison of NeuroSpan Bridge, NeuraGen Nerve Guide, and Nerve Autograft for ...

Peripheral Nerve Injuries

Auxilium Biotechnologies

NCT03967808 N/A

French Renal Epidemiology and Information Network (REIN) Registry

End-stage Renal Disease

Central Hospital, Nancy, Franc

NCT07414225 N/A

Safety and Efficacy of Transcatheter Edge-to-Edge Repair for Atrial Functional M...

Atrial Functional Mitral Regurgitation

Beijing Anzhen Hospital

NCT01915225 N/A

Obtaining Solid Tumor Tissue From People Having Biopsy or Surgery for Certain Ty...

Colorectal Neoplasms

National Cancer Institute (NCI

NCT06769776 N/A

Drain vs No Drain After Live Donor Hepatectomy

Donor Hepatectomy

Marengo Asia Hospitals

NCT06273293 N/A

Postprocedural Contrast Mediated FFR Plus Intracoronary Infusion of Nitroglyceri...

Coronary Disease

Fundación EPIC

NCT07402616 N/A

Ex Vivo Cutaneous SCC

Cutaneous Squamous Cell Carcinoma

Rigshospitalet, Denmark

NCT06655506 N/A

Enhanced Recovery Protocols in Gynecologic Oncology

National and Kapodistrian Univ

NCT07706647 N/A

Oil Pulling Reduction

The University of Texas Health

NCT05943249 N/A

Development of Novel MR Techniques Using Volunteer Participants

University College, London

NCT07815249 N/A

Speech Therapy for Children With Rare Genetic Conditions and Childhood Apraxia o...

Childhood Apraxia of Speech

Murdoch Childrens Research Ins

NCT06265038 N/A

Confirmatory Investigation to Evaluate the Performance and Safety of ReSpace TiC...

Degenerative Instability

Sanatmetal Orthopaedic and Tra

NCT06779058 N/A

MR Elastography for Assessing Liver Fibrosis in Chronic Hepatitis B

Chronic Hepatitis B

Shengjing Hospital

NCT06502548 N/A

Endometriosis Transcriptomic Cell Atlas

University Hospital, Toulouse

NCT05190848 N/A

Correlation of Microbiome and Metabonomics With IgA Nephropathy

IgA Nephropathy

Guangdong Provincial People's

NCT07375355 N/A

Real-world Study of Scemblix in the Treatment of Chronic Myeloid Leukemia in Chi...

Chronic Myeloid Leukemia in Chronic Phase

Novartis Pharmaceuticals

NCT07611526 N/A

Investigation of the Individual Fatigue Response During Blood Flow Restriction T...

Total Knee Anthroplasty

University Hospital, Bonn

NCT07213908 N/A

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

Children's Hospital Los Angele

NCT04020276 N/A

OAR-Based, Dose Escalated SBRT With Real Time Adaptive MRI Guidance for Liver Me...

Liver Metastases

University of Wisconsin, Madis

Page 3 of 276 — 6,885 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: September 2026 · Data Methodology