Prior to the time when any prospective new medicine can be determined, researchers need to have a comprehensive understanding of the disease they are looking to cure, as well as the condition’s underlying cause. They look at various factors such as: how any alterations in the genes have transpired, what the knock-on effect is to the proteins they encipher, how the proteins interact together in living cells, the way that affected cells transform the particular tissue that they are a part of, and how the patient is affected overall. The research needs to be carried out over many years, regardless of the new insights an tools. In the events where the research has been good, turning a fundamental comprehension of how a disease is generated into a suitable treatment will involve a lot more years of work (Drug Discovery, n.d.).
At this stage the researchers decide upon a “target” for a prospective new medicine. Generally speaking, a target relates to a single molecule, for example, a protein or gene, that plays a role in a specific disease. At this point it is vital that a “drugable,” target which had the potential to generate an interaction a drug molecule, and be affected by it is chosen by the scientists (Drug Discovery, n.d.).
Once the researchers have decided on a potential target, they must demonstrate that it is properly implicated in the disease, and that it can be affected via a drug.This demonstration to show the relevancy of a specific target towards a disease is studied by carrying out complex experiments utilizing both animal models of disease and living cells (Drug Discovery, n.d.).
Once the scientists have a good comprehension of the disease, then they are in a position to start searching for a drug. They look for a “lead compound” or molecule, which has the potential to act on the chosen target in order to change the course of the disease. If the scientists have success after years of testing, then the lead compound can eventually be produced as a new medicine (Drug Discovery, n.d.).
Methods to Look For a Lead Compound
At the present time there are now different routes to access drug discovery besides components from nature. Now, due to chemistry advances, scientists have the ability to generate molecules from scratch. They have cutting-edge computer equipment which can generate complex modeling that can pick out the kind of molecule that could work. Leads are normally found via the procedure of high-throughput screening, and progression in computational power and robotics give scientists the means to carry out trials using an extremely large number of compounds towards the target in order to establish any that could be potentially feasible. According to the results, a few of the lead compounds are normally chosen to carry out further research. In addition to this, in biotechnology, researchers are also able to generate biological molecules that have disease-fighting abilities for the genetically engineered living systems (Drug Discovery, n.d.).
After the initial screening, the lead compounds which make it through are “optimized,” in order to render them safer and more effective. If the compound’s structure is changed, scientists are able to furnish it with different properties. They may for instance, decrease its side effect potential by making it less inclined to act on other chemical pathways. The variations of the initial leads that are produced and tried out, run in the hundreds. During this period, the scientists consider the formulation of the drug (Drug Discovery, n.d.).
The researchers now conduct in vivo and in vitro experiments to ascertain the way the drug functions and to monitor its safety profile. The FDA stipulates comprehensive tests on animals before it can be trailed on humans. This discovery phase can last for three or four years, and at the end, just one to five molecules will be put forward as “candidate drugs,” to be researched during clinical trials (Drug Discovery, n.d., Medscape, 2001).
The Development Process
Prior to the beginning of any clinical trial, an application for an Investigational New Drug must be filed by the researchers with the FDA with details on the processes that have already been carried out (Drug Discovery, n.d.).
Phase 1 Clinical Trial
At this stage, human beings are tested using the candidate drug. This usually involves healthy volunteers in a group of approximately 20 to 100. The prime purpose of this stage is establish whether or not it is safe for humans. The trials are monitored very closely to help scientists ascertain the range of safe dosing, and whether it should continue to be developed further (Drug Discovery, n.d.).
Phase 2 Clinical Trial
This stage involves the evaluation of the candidate drug’s effectiveness in approximately 100 to 500 suffers to have the condition or disease that is being researched. At this stage, drug risks and other adverse effects are studied. As is the mechanism of action, the benefits, whether it should be administered orally or intravenously, dosage and schedules. If there is a promising drug, then it is put forward for the far larger Phase 2 Trial (Drug Discovery, n.d., Medscape, 2001).
Phase 3 Clinical Trial
During this stage scientists research the drug candidate by utilizing approximately 1,000-5,000 patients. This is for the purpose of producing significant statistics on effectiveness, safety data, and the drug’s entire benefit-risk relationship. This stage is central in ascertaining if the drug is effectual and safe (Drug Discovery, n.d.). This stage is the longest trial and the most expensive. A very large number of sites all over the world take part in the trial in order to give it diversity (Drug Discovery, n.d.).
- Drug Discovery and Development (n.d.).
- Medscape (2001). Retrieved from: http://www.medscape.com/viewarticle/405869_4