Lecture 9 Understanding Clinical Trials What is Risk Epidemiological risk refers to a probability the chance that something may occur but not a guarantee that it will Risks are determined by studying large groups of people to discover the probability that any given person or category of people will develop the disease over a certain period of time Looks at what characteristics or behaviors are associated with increased or decreased risk a specific time period Two categories of risk absolute and relative Absolute risk actual numeric chance or probability of developing cancer during Relative risk Gives you a comparison or ratio rather than an absolute value Interpreting Risk as When reading about cancer risk statistics pay attention to the details such Who s being observed A news report may say a certain activity increases the risk of cancer for a group of people But who was being observed in the study Pay attention to ages genetic predisposition and geography How many people were studied Studies with larger s of people are more accurate than studies that examine a small group Have similar studies been done The findings of one study are more reliable if they re similar to findings by other studies Incidence and Mortality during a specific period The incidence of a disease is the rate at which new cases occur in a population Mortality is the number of cancer related deaths during a specific time period The incidence and mortality rates describe the number of new cases or deaths from cancer per 100 000 people during a specific time period usually one year Prevalence Cancer prevalence the number or percent of living people who have ever been diagnosed with cancer It includes how often cancer occurs incidence and how long people live after diagnosis survival Prevalence rates express the number of cases of cancer per 100 000 people Clinical Trials How do we find and test new treatments Idea test tube trial animal trial human trials What are Clinical Trials A research study in human volunteers to answer specific health questions Fastest and safest way to find treatments that work in people that ways to improve health Types of Clinical Trials Prevention Prevent disease in na ve people or prevent disease recurrence Screening Test methods of find disease Diagnostic Test new treatment approaches Quality of life Improve comfort quality of life Compassionate use Provide partially tested unapproved therapeutics to a small number of patients who have no other realistic options FDA regulated Used in unresponsive patients Clinical Trail Design treatment or a placebo Randomized Subjects are randomly assigned to receive either the study Blind Subjects do not know which treatment they receive Double blind Researchers also do not know Placebo controlled The use of a placebo fake treatment allows the researchers to isolate the effect of the study treatment from the placebo effect perceived or actual improvement in a medical condition despite not receiving treatment Randomized Trials Participants have an equal chance to be assigned to one of two or more groups One gets the most widely accepted treatment standard treatment The other gets the new treatment being tested which researchers hope and have reason to believe will be better than standard treatment The Four Phases of A Clinical Trial Phase 1 Phase 1 studies are the first step in testing a medical intervention on human subjects and are primarily concerned with assessing the safety of that intervention Phase 2 Once a medical intervention has proved to be safe Phase 2 trials begin to test the effectiveness of a treatment and aim to establish whether the experimental drug is of potential benefit to people Phase 3 The aim is to gain a definitive understanding of the effectiveness benefits and potential side effects of the medical intervention under examination Phase 4 Initiated after the treatment has been approved Phase 4 is used to assess long term safety monitor impact on different populations and to determine the cost Clinical Trial Phases Phase 1 Goal Initial safety and tolerability Determine safe dosage range Identify side effects 20 80 subjects Phase 2 Goal Effectiveness exploratory Dose response Further evaluation of safety 100 300 subjects Phase 3 Goal Effectiveness confirmatory Monitor side effects Compare commonly used treatments Collect information that will allow the drug or treatment to be used safely 1 000 5 000 subjects Phase 4 Goal Effectiveness in the general population Optimizing drug use Patient population sample you How long does it take to get FDA approval Preclinical Testing Discovery of compound Testing in animals and cell culture 5 20 years or more Investigational new drug application filed with FDA Clinical Trials Phase 1 Test for safe dose Phase 2 Preliminary testing for effectiveness Phase 3 Randomized double blind trial 5 10 years New drug application filed with FDA FDA review 1 5 years FDA approval Approved Treatment Further evaluation of side effects and other uses ongoing Do Many People Participate in Cancer Clinical Trials Only 3 of U S adults with cancer participate in clinical trials 0 14 years old 50 0 15 19 years old 20 0 20 and older 2 5 70 and older 1 0 Protections for Participating in Clinical Trials The government has strict guidelines to protect trial participants Must be approved and monitored by an Institutional Review Board IRB An IRB in an independent committee of medical specialists nurses social workers medical ethicists and patient advocates who review clinical trial protocols at institutions that conduct medical research Informed consent must be obtained before participation is approved Possible Benefits of Participation Patient will receive at a minimum the best standard treatment If the new treatment or intervention is proven to work patients may be among the first to benefit Patients have a chance to help others and improve cancer care New treatments or interventions under study are not always better than or even as Risk of Participation good as standard care Even if a new treatment has benefits it may not work for every patient Health and insurance and managed care providers do not always cover clinical trails Why do so few cancer patients participate in clinical trials Doctors might Lack awareness of appropriate clinical trials Be unwilling to lose control of a person s care Believe that standard therapy is best Be concerned that clinical trials add administrative burdens Sometimes Patients Don t
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