Clinical Trials

Question 1

Phase 0 trial

Answer 1

Necessitated by the observation that about 40-50% of drugs fail in phase I, causing a huge waste of time and money; reduces chance of failure later

Goal: by using a small dose of drug in humans with a known bio marker for drug, the drug can affect the target

Less than 20 subjects

Requires that drug has wide therapeutic index and known target

Patients not allowed to get therapeutic benefit or enroll in trial with therapeutic intent

Question 2

Phase I Trials

Answer 2

Determine the max dose tolerated; Target is safety!

Look at pharmacokinetic data: absorption, distribution, metabolism, and excretion

20-100 patients looking at dose escalation

Question 3

Phase II Trials

Answer 3

Explore efficacy

Generate hypothesis based on observations, which can be tested

100-1000 subjects

Question 4

Phase III Trials

Answer 4

Confirm efficacy and safety profile in target population

Larger population, usually greater than 1000

Question 5

Phase IV

Answer 5

Determine if drug or treatment is safe over time (that were unlikely to be seen in short term trials) and if there are any other uses

Occurs after drug has already been approved by FDA

Post-market surveillance