At a time when the world is going through one of the biggest health crises ever experienced, it may seem strange to question why new drugs are important. The answer might not be as obvious as it may seem.
Drug Discovery Concept. Image Credit: metamorworks/Shutterstock.com
There are many reasons why new drugs are important, such as new diseases, the development of drug resistance, and our increasing understanding of health conditions allowing treatment of previously untreatable conditions. In some cases, it may not be a new drug that is required, but that a previously known drug can be used for a new purpose.
Antibiotics are one of the most commonly used and well-known drugs for fighting bacterial and fungal infections. Since 1990 only three new classes of antibiotics have been established, although many derivatives of existing drugs have been developed.
Drug Approval Process
One of the hindrances to developing new drugs is the process of approval required before drugs can be used. Traditionally, this is a long-drawn-out process taking up to ten years, which in the USA will cost around two and a half-billion dollars.
Normally the drug approval process requires at least several of the following phases:
- A drug is identified by a company as being likely to cure or prevent a specific symptom.
- The drug is tested on animals or laboratory cultured cells to check whether it has the required effect.
- A new drug application is launched and permission for human testing is requested.
- Human testing is then carried out in three phases
In phase one, 20 -80 healthy adults are given the drug to ascertain any side effects and check the metabolic pathway.
In phase two, hundreds of people tested to see if the drug is effective, usually run alongside another treatment, often a placebo, to allow a comparison. Safety and short-term side effects are assessed.
In phase three, thousands of people are assessed and effect use with other drugs and at different doses are assessed.
- Assessment by the relevant drugs authority to verify that the trials were successful and the drug does do what it claims without any undue side effects.
- Apply for a license to market and sell the drug assuming that trials have been successful.
It is easy to see why this process may cost a lot of time and money and the development of COVID-19 vaccines could be a major disrupter of this process as it has been much more rapid. It is not clear whether this has been because other approvals have been delayed, or what the cost implications are. The safety of any drug is always of paramount importance in the approval process.
Why are new drugs required?
New Diseases
The COVID-19 pandemic has highlighted the possibility of new diseases occurring. New drugs are required to treat the symptoms of new diseases but also to prevent the spread of new diseases by vaccination. The continued incidence of new diseases is likely to continue as humans interact more and more with other species. Many new diseases, like SARS-CoV-2, originate in animals. There are many examples of recent diseases that have crossed from an animal host to humans. Examples of virus transmission are HIV/AIDS, Ebola, flu, and even the common cold.
In addition to virus transmission, diseases can also be caused by bacterial or fungal infections or by animal-borne parasites such as malaria.
Previously Untreatable Conditions
As the pathology and metabolism of diseases are researched and understood, new drugs can be developed to treat the causes or the symptoms of diseases that have been known about for many years but have previously been untreatable.
Different Metabolisms
New drugs are sometimes required to treat different types of people, due to the different ways they are metabolized. Some drugs affect males and females differently because of their different biology. Some drugs are not suitable for both adults and young children, so different drugs may be required to treat children.
Low-cost drugs
Less expensive drugs are also required for countries with less wealth who cannot afford the more sophisticated drugs.
A disease may not be eliminated unless it is eliminated everywhere, so less expensive drugs are often necessary to treat people in poorer countries, to prevent the reintroduction of diseases from other countries. Pharmaceutical companies are often reluctant to lower the prices of their products as they have invested millions or billions in the development of these drugs, so cheaper alternatives may be required.
Drug resistance
One of the biggest reasons that new drugs are required is the development of drug-resistant bacteria and fungi. These so-called “superbugs” already kill around 700,000 people a year around the world and they are predicted to kill ten million a year by 2050. The growth of resistance is caused in part by the overuse of existing drugs. It is also true that some doctors prescribe antibiotics for viral infections when they will be ineffective and some patients demand antibiotics wrongly.
Antibiotics are sometimes used in animal husbandry indiscriminately which leads to the development of resistance. Drugs often kill 99.9% of the bacteria or fungus causing the infection. It is possible that the 0.01% who survive are resistant to the drug used and will now multiply and become the dominant form of that species and infect other people or the original host.
Drug resistance is not limited to antibiotic treatments. Viruses and parasites can develop immunity to their treatments and vaccinations currently in use. A good example of virus vaccination resistance would be influenza where we know the vaccination has to be modified every year to combat the evolution of the virus. An example of a parasite resistant to treatment would be malaria (caused by a single-cell parasite) where the effect of conventional treatments reduces with time.
Importance of New Drugs
Outlined above are some reasons why new drugs are required. New drugs must be developed so that we can continue our chosen lifestyles and prevent the misery and death caused by diseases. Disease-causing vectors continue to evolve, throwing up new challenges and in general, humans are living longer so they have more time to be exposed to diseases.
To maintain our health, we need to be able to fight against well-known and increasing health conditions, such as cardiovascular disease which kills seventeen million people a year, and new diseases such as COVID-19 which can massively disrupt the world and kill millions of people in the first year it occurs.
Sources:
- Wieseler B, McGauran N, Kaiser T. New drugs: where did we go wrong and what can we do better? BMJ 2019; 366 :l4340 doi:10.1136/bmj.l4340
- Jarvis, L.M. (2019). The new drugs of 2019. [online] Chemical & Engineering News. Available at: cen.acs.org/pharmaceuticals/drug-development/new-drugs-2019/98/i3.
- Science in the News. (2020). Modern Drug Discovery: Why is the drug development pipeline full of expensive failures? [online] Available at: https://sitn.hms.harvard.edu/flash/2020/modern-drug-discovery-why-is-the-drug-development-pipeline-full-of-expensive-failures/ [Accessed 12 Apr. 2021].
- STAT. (2020). We need new drugs to prevent the looming superbug crisis. [online] Available at: https://www.statnews.com/2020/08/12/we-need-new-antimicrobials-to-prevent-the-next-infectious-disease-crisis/ [Accessed 12 Apr. 2021].
- Shankar, Pr. (2016). Book review: Tackling drug-resistant infections globally. Archives of Pharmacy Practice, [online] 7(3), p.110. Available at: https://amr-review.org/sites/default/files/160525_Final%20paper_with%20cover.pdf.
Further Reading