Clinical Trials: Purpose and History

12 Questions

What is the main purpose of clinical trials?

To minimize risk to the patient while testing new interventions

Who typically designs clinical trials?

Doctors and specialists

What was the outcome of the 1747 scurvy trial by James Lind?

It showed that a particular diet could prevent scurvy

What is one of the potential consequences of not conducting clinical trials?

All of the above

What was the first randomized controlled trial for?

Treating the common cold with Patulin

What is a key characteristic of clinical trials?

They may involve interventions to modify lifestyle or behavior

What is the primary purpose of conducting a clinical trial in its first stage?

To test the safety and side effects of the treatment in a small group of patients

What is the main difference between a controlled trial and a blind trial?

A controlled trial compares different treatments, while a blind trial ensures that participants do not know which group they are in

What is the primary reason for conducting a clinical trial in its fourth stage?

To get stats on how well the drug is working on a large population

What is the estimated average cost of administering a 5.5-year clinical trial involving collecting data across 20 centers in the UK?

~£1M

What is the estimated cost of taking a drug from development to the market in the UK?

~£1.1 Billion

What is the proportion of drugs that make it through to stage 4 in clinical trials?

One in many

Study Notes

Reasons for Clinical Trials

Prevent disease and reduce the number of people who become ill
Treat illness and improve or increase the number of people cured
Improve the quality of life for people living with illness – reducing symptoms or side effects
For disease diagnosis and health problems

History of Clinical Trials

1747: James Lind conducted the first clinical trial in the modern era on scurvy
Early 1800s: The term "Placebo" was first defined
1943: The first double-blind controlled trial was conducted by the Medical Research Council
1946: The first randomized curative trial was conducted using Streptomycin to treat tuberculosis

Importance of Clinical Trials

Without clinical trials, patients could be given medicines that do not work
Resources could be wasted on ineffective treatments
Medicines could even make the patient worse

Design of Clinical Trials

Designed to offer the least risk to the patient but maximum potential new treatment or intervention being tested
Generally designed by doctors and specialists
Start with a systematic review of previous trials performed in the same area of disease or using similar drugs

Phases of Clinical Trials

Early Stage (Phase 1)

Tests the safety of the treatment in small groups of healthy subjects or patients
Assesses large side effects

Second Stage (Phase 2)

Tests the treatment in a larger group of people to assess safety and side effects in greater detail
Assesses the treatment's positive effect in patients

Third Stage (Phase 3)

Tests the treatment in hundreds or thousands of people, often internationally
Compares the new drug to a standard treatment
Assesses the drug's effectiveness and duration of effects
Finds out more about serious side effects and their duration

Fourth Stage (Phase 4)

The drug is licensed and used as a treatment
Collects data on the drug's effectiveness in a large population
Monitors long-term risks and benefits, including rare side effects

Types of Clinical Trials

Controlled Trial

Compares different treatments
Involves two groups: a trial group and a control group

Blind Trial

Participants do not know which group they are in
Some trials are double-blinded, meaning both participants and researchers do not know which group they are in

Assessments in Clinical Trials

Potential side effects
New symptoms
Quality of life, day-to-day activities, and mental state
Cost effectiveness of treatment, including the ability to work and visit the doctor