2. Clinical Trial Phases

Question 1

How many phases does a clinical trial consist of?

Answer 1

(Ordinarily) Four

Each Phase is designed to answer a separate question and is in itself a separate clinical trial.

Question 2

What has been conducted by the research companies prio to a clinical trial?

Answer 2

Preclinical Studies (laborator or animals) 
(for activity and toxicity data)

Question 3

How is Phase 1 done and why?

Answer 3

First into human. Small sample size.

Pharmacokinecit & Pharmacodynamic effects and MTD

Question 4

What is the Proof of Concept Phase?

Answer 4

A phase often inbetween Phase 1 and Phase 2.

Small Scale Trial to to determine whether a compound might have new indications (significant efficacy in other diseases)

Question 5

When can Phase 2 start?

Answer 5

In the absence of safety concerns

Question 6

On which sample size is Phase 2 conducted and what is the goal of a phase 2 trial?

Answer 6

1. Large Sample Size

2. Assess activity, feasability and toxicity of a given dose

Question 7

Compare 2a and 2b Phases

Answer 7

2a
Goal: Repeating safety assesment from Phase 1 on bigger scale
Focus: dose requirements, MTD, dose frequency….

2b
Goal: How well does the drug work at prescribed doses

Question 8

When can Phase 3 start?

Answer 8

Once it is proven that the drug is effective against the disease

Question 9

What is the goal of Phase 3?

Answer 9

to reach a definite assesment of the efficacy of the drug and provide large scale safety data.

Question 10

Compare 3a and 3b

Answer 10

3a
- Conducted prior to submission of the drug for a new drug application

3b
- Conducted after the regulatory submission but prior to approval and marketing

Question 11

When is Phase 4 conducted? Why is it done?

Answer 11

1. After the approval and marketing of the drug (often postlicencure or postregistration trials)
2. To gather information on the effects in various populations and side effects associated with long term use.