Hi there, I'm Mrs. Kemp, and welcome to today's lesson all about development of new medicines.

This fits into the medicines and new treatments for disease unit.

So let's get started then.

Our main outcome for today is I can describe the process of discovery and development of potential new medicines, including preclinical and clinical trials.

Today we'll be using lots of new key terms and they're here for you on the board.

However, if you would like to read them over in a little bit more detail, please do pause the video now.

We've got three learning cycles for today, new medicines, stages of new drug testing, placebos and blind trials.

Of course, we will start with new medicines.

So where do you think new medicines will come from? A little think about that for a moment.

So often plants can be a really good source of new medicines and we can use things that people have used in the past as a particular type of treatment, and maybe there is some sort of active ingredient in there.

An example of this then is that it's thought that willow bark has been used in medicine to reduce fever and inflammation since the time of Hippocrates.

That's about 400 BC.

The active ingredient from the willow bark was identified and then modified to make something that we know today as aspirin.

That took place in about 1899.

But obviously we do still use aspirin today as a really effective painkiller, so it prevents you from feeling pain.

Another example then is that there have been reports of extracts from foxgloves, that's that beautiful looking flower there, being used since Roman times to treat ailments such as heart conditions.

Now actually, the drug digitalis was first extracted from the foxglove in the 18th century, so they realised that there was actually something in there that was helping with people's heart problems. That drug is now sometimes used to treat people with an irregular heartbeat.

We can also find new drugs from microorganisms, and one very famous example that we know about then is Alexander Fleming was who was a Scottish scientist.

He accidentally discovered the first antibiotic, which is penicillin.

He went on holiday, and when he got back, he noticed that the bacteria that he was trying to grow on an agar plate had some contamination on it by a fungus.

Wherever that fungus was, the bacteria were not able to grow.

We can see back to that fungus there growing on an agar plate.

Penicillin became widely used in the 1940s then and was hailed as a miracle drug because of its effectiveness in treating previously incurable bacterial diseases.

So actually we found a real increase in people's life expectancy because of the discovery of antibiotics.

It is important to protect biodiversity, so the number of different livings species that we have in an area because plants and microorganisms are really important sources of new medicines.

Without willow trees and penicillin, penicillium fungus, sorry, we would not have the widely used drugs aspirin and penicillin.

In addition to this then, scientists will also try to synthesise new drugs, specifically trying to target pathogens or host cells in a laboratory scenario.

So they'll actually be trying to come up with some kind of chemical formula that will kill particular types of pathogens.

Okay, onto our first check then.

Can you match the organism to the medicine we get from it and then to what we use it for? I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay.

Did you realise that the fungus goes with penicillin and that kills bacteria? The foxglove goes to digitalis and treats an irregular heartbeat.

Willow goes with aspirin and that is a painkiller.

Excellent, well done.

So when a new drug is discovered, it's really important that we check to make sure that it is safe, that it's actually effective, so it's going to do what you want it to do, and also the level of that drug that you need in order for it still to be effective but safe.

There is a very famous drug known as the thalidomide that was developed in the 1950s.

There's the chemical formula of thalidomide there.

It was originally intended to be used as a sedative, so to make people feel relaxed and help them to sleep, but it was also used for other treatments, such as cold symptoms and also morning sickness in pregnant women.

When women are pregnant, they can often feel quite sick.

It doesn't actually have to be in the morning.

But they realised that actually thalidomide did seem to help women with these symptoms. Thalidomide had been tested on animals and the drug company deemed it to be safe to use on humans.

It quickly gained in popularity, so it worked really well and actually they sold it in almost 50 different countries.

It took five years to actually realise that thalidomide was actually causing problems for foetuses of those pregnant women.

It actually affected foetal development leading to limb difference, sight loss and hearing loss.

The problem was is that although they had tested the drug on animals, they hadn't actually done any testing on animals that were pregnant or then humans that were pregnant.

It's actually very difficult to get anybody to take part in drug development when they are pregnant because people just don't want to risk it.

It is actually estimated that 10,000 babies were affected by the drug worldwide and almost half died within the first year.

So this was really, really a terrible, terrible issue, and actually it took a long, long time for them to get the victims to actually get any kind of compensation back from the drug companies.

As a consequence, drugs must now go through a much more rigorous testing, and any drug marketed to pregnant women needs to provide evidence that it's safe to use while pregnant.

This is quite difficult and therefore a lot of drugs do not recommend to be used while they are pregnant.

Thalidomide is actually still being used today, but with much tighter regulations.

People with leprosy may actually take thalidomide because it does help to treat the disease.

However, the people would make sure that the person with that disease were not pregnant before taking thalidomide.

It's not a perfect system and actually since it's being used for leprosy, there have been a number of cases of babies born with those problems. New drugs are extensively tested.

What do scientists check for during these tests? A, the efficacy of the drug, B, the correct dosage, C, the overall smell and taste, D, whether it is safe to use? I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that it's the efficacy, the effectiveness of it, the dosage, so how much they need to use and whether or not it's actually safe to use.

Excellent.

Well done.

Okay.

Onto our first task of the day then.

This is task A, and you can record your answers on your worksheet.

Number one, describe where new medicines come from.

Number two, give an example of medicine developed for a microorganism, from a microorganism, sorry.

Three, using thalidomide as an example, explain why it is important to test any drugs marketed to pregnant women for safety whilst pregnant.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that number one, today many new medicines are created in a laboratory by scientists? Plants and microorganisms are also important sources of new drugs.

Number two, some fungi can produce antibiotics.

For example, the fungus penicillium produces the antibiotic penicillin.

Number three, thalidomide was tested on animals and then used for treating morning sickness in pregnant women.

The drug can affect development of the foetus, including causing limb difference, sight loss and hearing loss.

Medicines are now tested on animals and humans, and also evidence need to be provided to show they are safe to use when pregnant.

If you need to add any more to your answer, please do that now.

Okay, onto our second learning cycle of today, stages of new drug testing.

All new drugs are tested for safety effectiveness, also called efficacy and dosage.

There are two main stages of drug testing, there's preclinical and then clinical trials.

Preclinical trials has two phases.

Phase one is modelling and testing in cells, so new drugs are first tested using computer models.

Human cells grown in tissue culture.

We can actually see there that there are some hamster embryo cells that are growing in culture.

That would be the same way that we would grow human ones.

This test for effectiveness, so whether or not it actually does the thing that we're hoping it to do, and also safety, we can see whether or not those cells survive by putting the drug on them.

So the preclinical trials phase two is testing in animals.

All new drugs in the UK are tested on animals.

This is really important as it will show whether or not the drug has any toxic effects, okay, so can it lead to cell death? And also, has it got any side effects? What does this person experience when they take the drug? It can also allow us to work out the estimated dosage that is required.

They often use mice as they are small, they breed easily and they grow to adulthood really quickly.

They're actually really biologically similar.

Their organs are all in the same place and the same shape, they're just on a much smaller version than ours.

That will increase the validity of the results.

Of course, they are a different species to us, and therefore we can't always guarantee that what happens to the mice will be exactly the same as what happens to a human being.

But this is a really important phase to happen.

Testing on animals is strictly controlled, so we want to make sure that we're reducing any possibility that cruelty is occurring.

So the animals are very well cared for.

Experiments are strictly controlled to minimise any risk of suffering.

The scientists must prove that the benefits to the humans will outweigh the cost to the animals.

There are only a small number of places that are actually licenced for testing on animals.

We do not test on animals or in animals with cosmetics in this country.

In the UK, it is completely banned.

Number three, clinical trials testing in humans.

Phase one, scientists test the drug in a small number of healthy people to test for safety.

They would use healthy people at this stage usually because then you can see whether or not the side effects are to do with the illness, or actually is it because of the drug.

Phase two is testing people with the illness at very low doses just to make sure that it is effective, but it's also safe.

The optimum dose balances the effectiveness of the drug with its toxicity.

So whether or not it causes some side effects, but actually is it effective? Can you put these stages of drug testing in the correct order? A, animal testing, B, human clinical trials, or C, computer models and tissue culture.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, number one is computer models and tissue culture.

Number two, animal testing.

Number three, human clinical trials.

Excellent, well done.

Onto our next task of the day then, task B.

Please open up your worksheet, so you can record your answers on there.

Describe what happens at each stage of the trials for a new drug.

One, preclinical trials.

Two, clinical trials.

For each stage, include what the new drug is tested in, and what the new drug is tested for.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, so the new drug is tested using computer models and human cells grown in tissue culture.

These test for effectiveness, the efficacy and safety, including toxicity and possible side effects.

The drug is then tested in animals for effectiveness and safety.

These tests show if the drug has any toxic side effects and at what dose.

Clinical trials.

Initially, scientists test the drug in a small number of healthy people to check for safety.

They can move on to testing people with the illness at low doses to check for effectiveness and safety.

Excellent, well done.

Onto our final learning cycle of the day then, placebos and blind trials.

Have you ever heard of the placebo effect? You may have done.

People might have said it to you before.

So a placebo is a treatment or substance that is designed to have no therapeutic effect.

Okay, so that means that it's not actually going to make you feel better, improve diseases.

It has been recognised since the late 18th century that patients can feel a certain amount of relief from placebos.

So in the past when the doctor maybe didn't have anything to give you to make you feel better, so sort of in that 18th century time, they may have given you something that actually just to sort of relieve you and make you feel happy that you've been given something by a doctor.

This is the placebo effect, and actually lots and lots of tests have shown that the placebo effect does still cause a response in humans.

Placebos are actually used as a control in drug trials.

Some participants in drug trials are given the real drug, whilst others are given the placebo.

The participants will not know if they've received the drug or the placebo.

During a trial, the placebo will look like the drug.

Sugar pills can be used as placebos.

So if in the drug trial they were given medicine in the form of pills, what they would do is they would give the people that are receiving the placebo a pill that is actually just sugar, and it doesn't have the active ingredient of the drug in it.

Placebos allow psychological effects of the treatment to be measured in people in the control group.

So if they suddenly start feeling a little bit better, or if they suddenly get headaches because they've taken a new type of drug, then this can be measured against what the actual drug is making people feel.

See, this is compared with the effects of the real drug in people in the treatment group, so the true effectiveness of the drug and its effects on the body can be measured more accurately.

Okay, which is the best definition of a placebo? A, a pill that contains sugar, B, any drug or C, a treatment or substance that is designed to have no therapeutic effect.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that it is a treatment or substance that is designed to have no therapeutic effect? A pill that contains sugar, that is just an example.

It's not a definition for a placebo.

Okay, so how do they use these placebos in a drugs trial? They've got two different types.

You can have a blind trail.

This is when only the doctor knows which patient has received the placebo and which has been given the drug.

The patient is not aware, so cannot be biassed towards the new drug.

However, the scientists that are gathering the information, they might actually inadvertently be slightly biassed towards the drug working because they want to show that their research is actually making a difference.

The reason why the patient might be biassed then is that actually if they know that they've got a placebo, they might realise, well, they haven't given me anything.

It's not gonna make me feel any better, and it will reduce those placebo effects.

If they actually got the drug, they might feel the effects of a placebo anyway and it might make them feel better and record better results and data, even though the drug might not actually be helping.

Probably a better example is where you have a double blind trial.

This is where neither the doctor or the patient know who has the placebo.

This helps to reduce bias from the doctor and also the patient at the same time because neither of them know which one should have the better results.

Placebo controlled trials are a good way to test the effectiveness of new drugs.

However, if the new drug treats a serious disease such as cancer, we don't use a placebo as this would actually be unethical.

You can't give somebody that has a life-threatening disease, a sugar pill that is not gonna help that disease.

Instead, what they usually do is they usually use the current best treatment for that disease for the placebo, and then they will compare the new drug against the existing drug.

There is always a small amount of risk involved when participating in a drug trial.

Sometimes the volunteers are healthy and sometimes they are unwell.

Volunteers are often paid a very small sum of money, and this will depend on how long the trial goes on for, whether or not they have to go into a unit to really control the environment, and also that level of risk involved with that particular drug.

Onto another check then.

This one's a true or false.

Only healthy volunteers are used in clinical trials.

Is that true or false? Can you justify your answer? Healthy volunteers are used to check for side effects, or B, volunteers with their illness are used to check for the effectiveness.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that that was false? And that's because volunteers with the illness are also used to check for effectiveness.

Excellent.

Well done.

Onto our final task of the day then, task C.

Again, you can record your answer on your worksheet.

Number one, explain the difference between a blind and double blind trial.

Number two, why are blind and double blind trials used? Number three, in what situations is a placebo not recommended and why? I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, in blind trials then the doctor knows which is the placebo and which is the drug, but the patient doesn't.

In double blind trials, neither the patient nor the doctor knows who receives the placebo and who receives the new drug.

Why do we use them then? So blind and double blind trials reduce bias when testing a new drug.

If the patient doesn't know which drug they're receiving, they can't be biassed.

For example, if they knew they were getting the new active drug, they may think they're getting better, even if they weren't.

If they knew they had the placebo, they may think they weren't improving, as they may not think the placebo is going to work.

If the doctor knew who was getting the drug and who was getting the placebo, they might treat the patients differently or ignore data that doesn't prove their hypothesis.

In a double-blind trial, there is no bias from the doctor or the patients as neither knows who is getting the drug and who is getting the placebo.

When scientists are treating a serious disease such as cancer, it would be unethical to not give them a drug.

Instead, the current most effective treatment is used as a comparison.

Hopefully, you've got all those points down, but if you need to add some more, please do.

So, we're very nearly finished.

I just want to go through those key learning points with you.

Plants and microorganisms are a source of new medicines, but many new medicines are synthesised in the lab to target specific pathogens or host cells.

New drugs are tested for safety and effectiveness.

Preclinical trials involve computer models, tissue samples, and animals.

They test for effectiveness and safety, including side effects.

Clinical trials use healthy human volunteers to test for safety, and sick human volunteers to test for safety and effectiveness.

The optimum dose balances the effectiveness of the drug with its toxicity.

Blind and double blind trials can use placebos and test for effectiveness and safety efficacy of a treatment whilst avoiding bias.

I've gone through a lot today and I hope you've been able to keep up.

I've really enjoyed it and hopefully see you again soon.

Bye.