The final phase of drugs testing and clinical trials are human trials. These are the last hurdle before groundbreaking new treatments can be made available to desperate sufferers of diseases for which there are might be no cure or whose symptoms need to be relieved. But who takes part in these trials? Are they safe? Is there an alternative?
Here, pupils will learn about the processes that a drug must undergo before it can be used to treat patients. Computer modelling, tissue trials, animal testing and human trials are all vital stages and some of these are controversial and can provoke an emotional response. This lesson explores the ethics of testing on animals and humans, the need to exclude the placebo effect and the difficulties in making sure that the tests have identified all chance of harm. It draws on examples including thalidomide – specifically mentioned in the KS4 syllabus – genetic modification and botched human trials in France and the UK. Throughout the lesson students are encouraged to form their own opinions and evaluate the evidence.
Why teach this?
Animal research, clinical trials and gene therapy are three controversial topics that are emotive but essential to our ability to treat and cure disease. Students are encouraged to explore and discuss these topics with strong links to PSHEE and
In this starter activity, created by the Nuffield Council on Bioethics [AR1], show your students an image containing a monkey participating in animal based research. Students are asked to make statements relating to their assumptions of what is happening in the image. These need to come under the headings “It is certain that…”, “It is likely that…” and “It is uncertain that…” Students could come up with their own statements – such as “It is certain the monkey is sitting on a table” and “It is likely that the monkey is in pain” and so on. Provide a statement bank for students to use if they struggle to come up with their own ideas.
Use the PowerPoint activity prepared by the group Understanding Animal Research, to introduce students to why there is a need to test drugs on animals and what type of animals and procedures this type of testing applies to [AR2]. Further activities from the Nuffield Council on Bioethics could extend this section into a whole lesson and could diversify the discussion into PSHEE. Individual resources from Nuffield look at ethical guidelines; the experience of the animals involved; pressure groups and exploring both points of view; and the role of the law in protecting animals and researchers.
1– Creative construction
Biomedical engineers use the engineering design process to solve medical problems. To do this, they apply knowledge from biology, chemistry and physics to solve problems involving the human body. In this activity students review and practice what biomedical engineers do during the research phase of the engineering design process. In this practical example designed by Teach Engineering, they use the information on an imaginary drug “Outstandix” and carry out an experiment to determine what health complications might occur in humans if we were to administer this drug [AR3]. Outstandix is designed to slow or stop the process of inflammation that causes pain in patients.
Animal testing has gone smoothly and seems to provide relief from inflammatory pain. So far, no negative side effects have been seen in the animals, but this drug has been shown to drastically reduce the levels of a protein called Osteopontin in the blood, urine and joint (synovial) fluid. Although no side effects have been seen in the test animals, it is important to research all effects of Outstandix before beginning human testing. Your students could either research what others have already learned about Osteopontin using the research sheets provided by Teach Engineering. Alternatively, to speed up this part of the lesson, you could simply tell students that one of the possible consequences of taking this drug is that calcium might precipitate out of solution.
Students then conduct a simple experiment to see what happens when solid calcium precipitates out of solution. To do this, distribute a saturated solution of CaCl2 and a saturated solution of K3PO4 in two beakers. Students will also need stirring rods and safety glasses. Direct students to carefully mix the two solutions together and stir with the glass rod. It may take five minutes or so for the precipitate to form at which point the solution will appear cloudy. Direct students to stop stirring and observe as the solid falls out of solution. In this reaction calcium phosphate precipitates out of solution. Encourage students to think about how this may apply to the solutions present in our bodies. In reality this might lead to complications such as pulmonary embolism or kidney stones, which should prevent the drug going for a real human trial.
2 – Test it on me
Human clinical trials are an essential part of the process of bringing a drug to the market. Phase one trials are the most risky and will be the first time the drug has been given to anyone. The participants are usually healthy people who are monitored for side effects when they take the drug. Ask students to use the NHS website [AR4] to design a flowchart showing the process for clinical trials through phase 1 to phase 4. Then divide the class into three groups. One of the groups represent a pharmaceutical company who are going to run a clinical trial for a new imaginary cancer drug called Remedium-X, the second group are cancer sufferers who want to take part in the trial to have a chance to try a new drug, the third group are healthy volunteers who want to earn some money by participating in the clinical trial. Students need to research their respective roles and present back to the whole group. The students representing the pharmaceutical company should design a form to fill in that asks all the questions they will need a prospective participant in the trial to complete. The cancer sufferers group should investigate the meaning of a double blind trial and what it would mean for them if they were given a placebo. The healthy volunteers should research occasions where clinical trials have gone wrong and permanently harmed the participants. Indicative websites include UK Clinical Trials Gateway [AR5], Cancer Research Clinical Trials [AR6], BBC News account of damaging French clinical trials [AR7] and Independent news article “The Troubled History of Clinical Drugs Trials” [AR8].
How soon should we intervene to prevent illness? Students should investigate the use of genetic screening and treatment of embryos to reduce hereditary diseases. Why does screening “unhealthy” embryos cause some people to be concerned about a future of “designer babies”?
Drugs that have been tested on animals, and then successfully in humans, can go on to become widely distributed in the population. Thalidomide was such a drug; amongst other uses it was a cure for morning sickness, which was effective and considered safe. However, thalidomide had not been tested in pregnant women, because you cannot take part in a clinical trial if you are pregnant. The drug led to catastrophic birth defects affecting thousands of children who were born to mothers who had used the drug. Useful resources to promote discussion of the pharmaceutical disaster include the Thalidomide Society website [AR9]. Another group of people who rarely participate in clinical trials are children under the age of 18; this can mean that once a drug becomes available it is only licensed for adults. A number of charities and campaign organisations claim that this unfairly excludes young cancer sufferers from potentially lifesaving treatments [AR10]. Pull the main activities together by asking students to use this information along with thalidomide and the availability of drugs to childhood cancer sufferers, to construct a set of 10 top guidelines for all pharmaceutical companies to use.
[AR4] Clinical Trials NHS
[AR9] The Thalidomide Society
About our expert
Dr Joanna L. Rhodes M.Chem, D.Phil, MRSC is a teacher of science at Shelley College, Huddersfield.