What is a clinical trial and how does it work? Flashcards
How does drug development take place?
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What are controlled clinical trials?
A clinical trial is a series of tests that scientists need to conduct when they come up with new ideas for new drugs, new medical procedures, or medical devices. Medicines and Healthcare products Regulatory Agency (MHRA) of the United Kingdom (UK) and the Food and Drug Administration (FDA) of the United States of America (US) are the regulatory authorities which approve drugs or devices or claims made by pharmaceutical companies.
What are the different phases of clinical trials? And how long does each phase roughly take?
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How is a phase 1 clinical trial conducted?
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Methods:
• First in Man : Small number of healthy volunteers
• First in a small group of 20 to 25
• Start with a dose of about 1/10 to 1/5 tolerated animal
dose
• Slowly increase the dose to find a safe tolerated dose
• If safe in a larger group of up to about 50 –75
• No blinding
• Performed by clinical pharmacologists
• Performed in a single centre
• Takes 3 – 6 months [ 70% success rate]
Describe phase 2 of a clinical trial
Phase II
• First in patient [ different from healthy volunteer]
• Early phase [20 – 200 patients with relevant disease]
• Therapeutic benefits & ADRs evaluated
• Establish a dose range to be used in late phase
• Single blind [Only patient knows] comparison with standard
drug
• Late phase [ 50 – 500]
• Double blind
• Compared with a placebo or standard drug
• Outcomes
• Assesses efficacy against a defined therapeutic endpoint
• Detailed P.kinetic & P.dynamic data
• Establishes a dose & a dosage form for future trials
• Takes 6 months to 2 years [ 35% success rate]
Describe phase 3 of a clinical trial
Phase III
• Large scale, Randomised (why?), Controlled trials (RCT)
• Target population: 250 – 1000 patients
• Performed by Clinicians in the hospital
• Methods
• Multicentric Ensures geographic & ethnic variations
• Randomised allocation of test drug /placebo / standard drug
• Double blinded:
• Vigilant recording of all adverse drug reactions
• Rigorous statistical evaluation of all clinical data
• Takes a long time: up to 5 years [25% success]
Describe post 4 of clinical trials
- No fixed duration / patient population
- Starts immediately after marketing
- Report all Adverse reactions
- Helps to detect
- rare ADRs
- Drug interactions
- Also new uses for drugs
Describe all participating parties involved in clinical trial
- Patient / Healthy volunteer
- Clinical Pharmacologist, Clinical
Investigator & team: [Qualified and
competent] - Institution where trials are held :
[Approval required] - Research Ethics Committee (REC) or
Institutional Ethical Committee - Sponsor
- Regulatory Authorities.
What individuals are found inside research ethics committee, sponsor and regulatory authorities?
Institutional Ethical Committee: – Supervises and monitors every step; – Safeguard the welfare and the rights of the participants • [5] Sponsor (responsible for trial) – Pays for all expenses; – Appoints competent investigators, – Ships all drugs for the trial, – Files all papers to legal / regulatory authorities, • [6] Regulatory Authorities: – Legal authority on the outcomes of the trial (e.g. MHRA, HPA ect)
Describe the clinical trial protocol
Title & Abstract • Introduction • General statement of purpose • Complete Preclinical results on animal study • Clinical data if available • Goals: Primary & secondary objectives • Study Design: • Type of study • Recruitment criteria : Exclusion & Inclusion criteria • Randomisation criteria and Sample size • Duration of study • Data Analysis: • Case report forms, Statistical Analysis, Bibliography
What are the diff types of study designs?
- Observational designs
- Experimental designs –interventional studies
Describe the types of observational studies
What are the two types of observational studies?
• Cohort Studies
• A group of subjects followed over time
• Purpose: defining the incidence and investigating potential causes of a
condition (incidence)
• Can be prospective – investigator chooses a sample group and measures
characteristics in each subject over a period of time that might predict
outcomes
• Can be retrospective – same as prospective, except all data collection and
follow-up has happened in the past; only possible if adequate data is available
Describe experimental studies
These studies evaluate the effects of an intervention
• Types of interventions:
• Behavior modification (eg. a walking program to improve weight loss)
• Drug (eg. a new investigational drug or studying a drug for off-label use – subject to FDA
regulations)
• Device (eg. a new investigational stent – subject to FDA regulations)
• Strength: Can demonstrate causality
Describe parallel vs crossover designs
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How is a trial started?
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