Phase 1 Clinical Research

Before medications and devices can be approved, they must first be tested.  Testing must be done for new medications/devices, new uses for approved medications/devices, or for approval to use products already in use in other countries.

The approval process starts with testing in a laboratory or with animals to determine potential toxicity.  Then testing progresses with research trials with human volunteers.  Clinical research trials are designed to determine a safe dosage range and identify any potential side effects of a new treatment.  The approval process for human volunteers takes place in Phase I-IV clinical research trials.  Typically the Phase 1 research stage lasts for one to two years.  It is estimated that 30% of products in Phase 1 research will successfully advance to Phase II.

The Food and Drug Administration (FDA) is responsible for the approval of new medications and devices, as well as new uses for products that have been approved.  Testing and FDA approval is mandatory before any pharmaceutical product can go into production to help patients.  Research trials are conducted under strict regulations and protocols.

The FDA is responsible for the protection of participants of clinical research trials as well as providing reliable information for subjects who are interested in participating.  Each trial has a detailed research plan, or protocol, that is carefully reviewed by an independent ethics board and designed to help ensure the safety of every volunteer.


Phase 1 trials primarily determine the safety of a treatment in humans and whether it is well tolerated.  While most Phase I clinical trials require healthy adults, each study is different.  For instance, some trials may be testing for a particular age group, gender, a specific medical condition or those taking a particular medication. It all depends on what the researchers are investigating.

If you don’t qualify for one trial, you may fit the criteria for the next.  Phase 1 trials are conducted with healthy subjects as well as subjects with a specific condition or disease.

As a general rule, in order to qualify to participate in studies with ICON:

  • You must be 18 years or older
  • Have the required BMI for the particular study
  • No usage of any illegal drugs
  • Legal (and current) government ID and Social Security number.

To find out if you meet the criteria for a trial, you can contact our recruiters. Or, you can view the study description online and then schedule a screening appointment. You can also be added to our database by filling out our online questionnaire.

At your screening visit, you will be provided with information about the study in a document called an informed consent form (ICF).  The ICF describes the study in detail including the purpose of the study, length of the study, possible risks/benefits of your involvement, procedures (such as vital signs, ECG, etc.) the lab work to be done, compensation, etc. The potential risks depend upon the treatment being studied.  All this information will be reviewed with you by a Registered Nurse or Doctor. If a subject is eligible, he/she must sign the ICF to be enrolled in the study and before any study procedures can be performed.

If you agree to participate, staff will review your medical history, medications and conduct the screening procedures outlined in the ICF. One of our doctors will give you a comprehensive physical to assess your health status. Once all results are obtained, your information will be compared against the study criteria. You will then be informed if you qualified or did not pass based on the criteria for that particular study. Study participation is monitored and carefully assessed starting with the signing of the ICF, during the trial and after it is completed.

Research Terminology

ICON Early Phase Services conducts a wide variety of Phase I studies.  Some of the terms can be described in multiple ways and this can be confusing.  Below is a list of terms for your reference. 





  • Alzheimer's research studies
  • allergy studies: seasonal allergies
  • asthma studies
  • bunionectomy studies - removal of a bunion
  • compensation: research study compensation, research volunteer, study participant, stipend
  • depression studies
  • dermatological studies: atopic dermatitis, eczema
  • diabetic studies: type 1 diabetic, type 2 diabetic clinical research, type 2 diabetic on 2 medications, insulin dependend diabetic, diet controlled diabetic, type 2 diabetic on metformin, type 2 diabetic research trial, type 2 diabetic with high blood pressure
  • gastrointestinal studies: inflammatory bowel (IBS) disease, constipation
  • healthy studies:  similar to other terms such as healthy clinical trial, healthy men and women, healthy patient study, healthy research study, healthy research subjects, healthy research trial, healthy volunteers
  • high blood pressure studies: hypertension
  • high cholesterol studies: hyperlipidemia 
  • inflammatory disease studies: arthritis, Celiac disease, Crohn's disease, fibromyalgia, psoriasis 
  • men's studies: prostate, erectile dysfunction
  • obese and overweight studies
  • pain studies: acute pain, chronic pain
  • peripheral arterial disease (PAD) studies
  • renal studies: kidney disease
  • research studies: similar to other terms such as investigational research, research study, clinical research study, clinical trial, research trial, research site
  • respiratory infection studies
  • senior study: for subjects age 65+
  • sickle cell disease studies
  • vaccine studies: flu, influenza, infectious diseases
  • women's studies: hot flash, oral contraception, menopause, osteoporosis, postmenopausal, childbearing, non-childbearing, birth control
Term Definitions

Clinical research uses terminology from a variety of resources including the medical field, clinical research, science, government regulation, etc.  The use of these terms varies according to the type of study being described.  Below is a list of some terms that you may come across in reading about study descriptions.

Abbreviation               Full Description
AE               Adverse Event
AMPM               Ambulatory Blood Pressure Monitoring
ARM               Any treatment group in a randomized research study
Anaphylaxis               A serious, life-threatening allergic reaction
BP               Blood Pressure
BMI               Body Mass Index 
Baseline               Information gathered at the beginning of the study 
Biologic               Virus, toxin, vaccine, etc. for the treatment or cure of diseases
Blinding               Process in which one or more parties in a research study is unaware of the treatment assignments
CBC               Complete Blood Count 
CRC               Clinical Research Coordinator 
CRF               Case Report Form
Caffeine/xanthine products               Products such as tea, coffee, chocolate, cola 
Cardiovascular               Related to the heart or blood vessels 
Cerebrovascular                Arteries supplying oxygen to the brain 
Cholecystectomy               Gallbladder removal 
cohort               A group; studies may have one or more cohorts 
DDI               Drug-Drug Interaction 
DNA               Deoxyribonucleic Acid
DNQ               Did Not Qualify
Dermatology               Related to the study of the skin and its diseases
Double-blind               Study design in which neither the investigator nor the subject knows which medication (or placebo) the subject is receiving
ECG               Electrocardiogram
EDC               Electronic Data Capture
Early Phase               The first of four phases in clinical research
Endpoint               The overall outcome that the protocol is designed to evaluate 
Endocrine system               Collection of glands that produce hormones that regulate metabolism, growth and development
Exclusion criteria               Criteria that prevents a subject from participation 
FDA               Food and Drug Administration
FIH               First In Human study; introduction of a drug into humans for the first time 
Formulation               Mixture of chemicals and/or biologic substances used to prepare dosage forms
GCP               Good Clinical Practice
Gastrointestinal generic drug               Related to the stomach and the intestines a medicinal product with the same active ingredient but not necessarily the same inactive ingredients as a brand-name drug
HCV               Hepatitis C Virus
HIV               Human Immunodeficiency Virus
Hematology               The study of blood, blood-forming tissues and the diseases associated with them
ICF               Informed Consent Form
IMP               Investigational Medicinal Product
IRB               Institutional Review Board
Immunology/infectious diseases               Diseases affecting the defense mechanisms of the body 
Inclusion criteria               List of criteria that must be met by all study subjects
Indications               Uses or indications for which the drug has been FDA-approved (e.g., migraines, seizures)
KG               Kilogram
Lymphatic disease               Affecting tissues /organs such as bone marrow, spleen, thymus, lymph nodes
MAD               Multiple Ascending Dose
MG               Milligram
MTD               Maximum Tolerated Dose
Metabolic               Breakdown of food & transformation into energy
Muscular dystrophy               Progressive weakness/loss of muscle mass
Musculoskeletal                Related to the muscles and bones of the body 
Myocardial infarction               Heart attack
Nephrology/urology               Diseases of the kidney and urinary tract 
Non-childbearing               Unable to have children due to a surgical procedure (e.g., tubal ligation, hysterectomy, oophorectomy) or being postmenopausal
OTC               Over-the-counter drugs 
Obstetrics/gynecology               Pertaining to the care of the women's reproductive system in general
Oncology               Medical, surgical and radiation treatment of tumors 
Ophthalmology               Field of medicine concerning the eye and eye disease 
Orphan drug               FDA designation to indicate a therapy develops to treat a rare disease
Otolaryngology               Field of medicine involving the ears and larynx; as known as ENT (ears/nose/throat) 
PD               Pharmacodynamics - how a drug affects the body
PI/Principal Investigator               Medical professional who is responsible for the overall conduct of the clinical research study 
PK               Pharmacokinetics - how the body affects a drug
Phase I               The first of four phases in clinical research
Placebo               Inactive substance to resemble the drug being tested
Postmenopausal               Females who no longer have a menstrual cycle; due to a surgery or naturally occurring 
Protocol               Detailed plan describing the objectives, study design and methodology for a clinical research study
Psychiatry/psychology               Medical field related to mental disorders and their treatment and prevention
Pulmonary               Related to the lungs
Randomization               Assignment to a group in a way that each subject has an equal chance of being assigned to each treatment
recruitment               Enrolling subjects with the proper inclusion criteria
Renal               Relating to kidneys
Respiratory               Breathing; organs of respiration
Rheumatology               Field of medicine related to joints, tendons, muscles, ligaments and associated structures 
SAD               Single Ascending Dose 
SAE               Serious Adverse Event
Single-blind                Study design in which either the investigator or the subject is unaware of which medication (or placebo) the subject is receiving
Source data               All information contained in original records and certified copies of results and observations required to reconstruct and evaluate the study 
Sponsor               Individual, company, institution or organization taking responsibility for the initiation, management and financing of a study
WBC               White Blood Cell

For more information contact:

Clinical Pharmacology Unit:

USA – San Antonio, Texas

8307 Gault Lane

San Antonio, TX 78209 USA

Telephone: +210-225-5437


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Volunteer Experiences

Our volunteers' views of what it means to take part in a study.