PHASES OF CLINICAL TRIALS
“Clinical trial” means a systematic study of new drug(s) in human subject(s) to generate data for discovering and / or verifying the clinical, pharmacological (including pharmacodynamic and pharmacokinetic) and /or adverse effects with the objective of determining safety and / or efficacy of the new drug. “
Drug Development Process:
The process of drug development can be broadly classified as pre-clinical and clinical
Pre- clinical refers to experimentation that occurs before it is given to human subjects; whereas, clinical refers to experimentation with humans. Within the realm of clinical research, ...view middle of the document...
Phase I Trials
Phase I trials are intended to demonstrate the safety of a new therapy or combination of therapies. Most phase I studies are performed with successive small groups of patients being treated at increasing doses to define what side effects occur and at what dose level
Purpose: to determine the SAFETY of the investigational drug.
Other Objectives include: To determine…
a. Maximum Tolerated dose (MTD)
d. Early Measurement Of Drug Activity
Study Design: Unblinded, uncontrolled study
▪ Generally, normal volunteers without confounding diseases or concurrent medications are recruited to participate in Phase I trials.
▪ With antineoplastic agents and for certain disease states and to avoid trials in normal subjects, it maybe preferred to begin trials in a patient population.
No. of subjects: 20 – 60
Length of Studies: Several Months
3. Phase II Trials
Phase II studies are designed to explore the therapeutic efficacy of a treatment or drug in people who have the condition that the drug is intended to treat. They are sometimes called therapeutic exploratory trials and tend to be larger scale than Phase I trials. Many experimental drugs which fail tend to do so during the Phase II trials.
Purpose: To Demonstrate EFFICACY with particular disease
• An important goal for this Phase is to determine the dose(s) and regimen for Phase III trials.
• Additional objectives of Phase II studies can include :
• Evaluation of potential study endpoints
• Evaluation of therapeutic regimens (including concomitant medications)
• Evaluation of target populations (e.g. mild versus severe disease) for further studies in Phase II or III
Study design: Single blinded, placebo controlled
• Subjects in Phase II trials are patients with the disease or clinical situation being examined.
• They should be healthy in terms of their disease and free of other serious medical illnesses.
Length of studies: Few months or take up to several years
No. of Subjects: 60 – 200
Phase II trials can be divided into Phase IIA and Phase IIB although sometimes both are combined
Phase IIA is designed to assess dosing requirements i.e. how much of the drug should patients receive and up to what does is considered safe. The safety assessments carried out in Phase I can be repeated on a larger subject group. As more subjects are involved, some may experience side effects which none of the subjects in the Phase I experienced. The researchers aim to find out more about safety, side effects and how to manage them.
Phase IIB studies focus on the efficacy of the drug i.e. how well it works at the prescribed doses. Researchers may also be interested in finding out which types of a specific disease or condition would be most suitable for treatment.
3. Phase III Trials
Phase III trials are the...