Clinical Trial Design and Phases Flashcards

What is the primary objective of a Phase I clinical trial?

Answer: Assess safety, tolerability, and pharmacokinetics, usually in a small number of subjects

Phase I trials are first-in-human studies, usually in 20–80 subjects (often healthy volunteers). They focus on safety, tolerability, dosing, and pharmacokinetics.

In a double-blind trial, who does not know the subjects' treatment assignments?

Answer: Both the subjects and the investigators/study staff

In a double-blind trial, neither the subjects nor the investigators and study staff who assess them know who is getting which treatment. This reduces bias in both reporting and assessment.

What is the main purpose of randomization in a clinical trial?

Answer: To reduce selection bias and balance known and unknown confounders between groups

Random assignment prevents investigators from choosing who gets which treatment and tends to balance baseline characteristics across groups. This supports valid comparisons.

Under an intention-to-treat (ITT) analysis, subjects are analyzed:

Answer: In the group they were randomized to, regardless of adherence or withdrawal

ITT analyzes subjects in the group they were originally randomized to. This preserves the benefit of randomization and reflects real-world effectiveness.

Which type of study is typically conducted after a product has received marketing approval?

Answer: Phase IV

Phase IV (post-marketing) studies look at long-term safety, rare adverse events, new populations, or additional uses after approval.

In a crossover design, which statement is true?

Answer: Each subject receives the treatments being compared in sequence, often with a washout period in between

In a crossover trial, each subject receives the treatments being compared in sequence, so each subject acts as their own control. A washout period reduces carryover effects. This design works best for stable, chronic conditions.