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

NCT07069491 N/A

Search About Contributing Factors That Leading to Intradialytic Hypertension in ...

Intradialytic Hypertension in Hemodialysis Patients

Sohag University

NCT07459621 N/A

Evaluation of a Novel mHealth Intervention for People Who Are Ambivalent About Q...

Smoking Behaviors

Kaiser Permanente

NCT06340516 N/A

NT-proBNP to Assess Trastuzumab-induced Cardiotoxicity

Vastra Gotaland Region

NCT06915584 N/A

Drug Management in Heart Failure

IRCCS San Raffaele Roma

NCT04769947 N/A

Italian Treatment Free Remission Registry

Treatment Free Remission

University of Turin, Italy

NCT02670447 N/A

Early Identification of Patients Presenting a First Psychotic Episode, Non Answe...

Centre Hospitalier Universitai

NCT07375147 N/A

Transanal vs Transvaginal Rectal Resection for Anterior Rectocele

Rectocele; Female

Cairo University

NCT07809347 N/A

Evaluation of the Factors Associated With BRADYcardia Following Pulmonary Vein I...

Atrial Fibrillation (AF)

Wroclaw Medical University

NCT07625358 N/A

Investigating the Effect of Caffeine and Alcohol on Pupil Dynamics

National University of Singapo

NCT06422078 N/A

A Non-interventional, Prospective Study With Benralizumab

Asthma, Bronchial

NCT06277778 N/A

Effect of Combined Music and Taekwondo Training for Children with Autism Spectru...

Autism Spectrum Disorder

The Hong Kong Polytechnic Univ

NCT07573085 N/A

Internet-delivered Emotion Regulation Individual Therapy or Adolescents (IERITA)...

Nonsuicidal Self-Injury

Karolinska Institutet

NCT06997315 N/A

Bath Myorhythms Project

Metabolic Regulation

University of Bath

NCT06467825 N/A

Effect of Sex on Orthostatic Intolerance and Cardiovascular Response During Luna...

National Aeronautics and Space

NCT06861868 N/A

Brain and Behavior Influences on Obesity Development From Infancy Through Childh...

Obesity and Overweight

Johns Hopkins University

NCT07683650 N/A

Hyaluronic Acid and I-PRF Mixture for TMJ Disc Displacement Management

TMJ Disc Displacement With Reduction

Mansoura University

NCT07050550 N/A

A Prospective Study of ¹⁸F-DFA PET Imaging for the Assessment of Liver Injury

First Affiliated Hospital of Z

NCT06085950 N/A

Transcranial Ultrasonic Stimulation in Treatment-resistant Depression : an Open-...

Treatment Resistant Depression

Centre Hospitalier St Anne

NCT05479474 N/A

Platelet Rich Plasma Testis Treatment for Infertile Men

Male Infertility

Stanford University

NCT06794047 N/A

The Effect of VitC on IVF Outcome of DOR Patients

Diminished Ovarian Reserve

Peking University Third Hospit

NCT03867448 N/A

Study of Endocrine-Related Conditions and Physiology

Endocrine Disease

National Institute of Diabetes

NCT07154355 N/A

Community Exercise Treating Effect on Cardiopulmonary Disease Patients

Coronary Heart Disease (CHD)

Guangdong Provincial People's

NCT04270578 N/A

Gestational Diabetes

Gestational Diabetes

University Hospital Tuebingen

NCT05663385 N/A

Mucograft Seal in ARP Follow-up

Erasmus Medical Center

NCT06925425 N/A

Effect of Task Specific Electrical Stimulation on Upper Limb Gross Motor Skills ...

Cerebral Palsy (CP)

Kafrelsheikh University

Page 15 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