Introduction of Drug Development Process
The development of medicines is a long process that involves several steps and stages. The drug development takes approximately 10 to 15 years. This includes the time from the initial discovery of a molecule to FDA approval, covering time spent in a market release. It’s not only time-consuming but also costs around $2.6 billion per successful drug discovery and development. This highlights the intricate nature of developing safe and effective medicines while maintaining strict regulatory standards.
The success rate of drug development clearly reflects the complexity of the process. Only 12% of drugs make it through the entire development phase. In 2022, the FDA approved 37 novel drugs, a comparatively small fraction of the drugs that entered this competition.
Despite these challenging situations, each attempt at successful or unsuccessful drug approval contributes to knowledge. It plays a huge role in understanding disease processes and potential treatments.
5 Key Stages of Drug Development
1. Discovery and Development
The drug development journey begins in research laboratories where scientists work to detect specific biological molecules like DNA sequences, RNA molecules, proteins, or metabolites, playing crucial roles in disease identification.
This stage covers:
- Target identification and validation: Scientists explore various targets and try to identify the target responsible for the disease. Based on the target, attempts are made to find out possible modalities to combat the target, either by modification or by blocking, to alleviate the disease.
- High-efficiency screening: A large number of chemical compounds are tested to see if they interact with the target. This is like checking different keys to find one that fits in a lock. This process takes place through molecular biology principles.
- Evaluation of performance and viability: Once scientists determine a potential drug, they run experiments to see how well it works and whether it can be compatible and work in the human body. To understand the physicochemical and biological characteristics of the compound, scientists ran several experiments on animal models and specifically designed in-vitro models. The favorable results of such experiments help to undertake future studies in drug development.
2. Pre-Clinical Research Studies
Assessing absorption, administration, and side effects of the drug under discovery:
The interaction of the drug within the body fluids is an important aspect for it to be available for a physiological action. Thus, experiments are conducted in animal models as a part of preclinical development. Prior to human testing, preclinical evaluation is a must. It is conducted in vitro (in test tubes) or in vivo (in animals).
The objectives of preclinical experiments are to determine the toxicity profile of the compound and to evaluate its pharmacological actions. For such experiments, rodents and nonrodent species are selected, and the compound under test is given, starting from minimal concentration to the highest concentration, to study its toxicity profile. Drugs with minimal toxicity at the highest doses qualify for the next stages of development. The physiological actions of the compound at various dose levels are evaluated in animal pharmacological studies, including its pharmacokinetic and pharmacodynamic actions.
3. Clinical Research
Preclinical research plays a very significant role in the drug development process. This stage is followed by the clinical research stage, wherein the interaction of drugs with the human body is studied.
The main objective of conducting clinical research via clinical trials is to understand the drug’s safety and efficacy in humans. Clinical research is conducted to test the safety and efficacy of drugs in humans. These are divided into 4 stages: each stage is designed to gather specific data to understand drug interaction with humans.
- Phase I : Phase I of clinical trials tests the efficacy and safety of the drug on a relatively small population size. It tests 20 to 100 healthy volunteers or patients who participate in clinical trials over a month. The primary goal of this stage is to identify a safe dosage, body-drug interaction, and potential side effects.
- Phase II : The results obtained after conducting clinical trials are assessed, and if the results turn out promising in that stage –– the drug moves to phase II. This phase involves several hundred patients suffering from disease conditions that the drug under study can potentially treat. This phase lasts from several months to a few years. This phase tracks the activity of the drug and continues to monitor its side effects. Very few drugs come with the fate of entering phase III. Only 33% of the drugs manage to reach phase III.
- Phase III : Phase III is the most critical stage in drug development, as it tests drug safety and efficacy on a relatively larger population size. The drug is tested on 300 to 3,000 patients over one to four years. This strengthens the research by confirming the drug’s effectiveness on a larger scale. This helps us to monitor adverse reactions caused by drug administration. The success rate of the drugs in phase III is very low, with 25 to 30% of drugs clearing this phase. After the drug successfully completes this phase, it is ready to obtain marketing authorization from the regulatory authorities.
- Phase IV : Phase IV studies are post-approval studies, and their main goal is to focus on the long-term safety of the drug. This stage also gives a clear idea about the rare side effects and other side effects that may arise from long-term use of the medicines. This is the advanced phase, which also collects more data about drug use in the real world.
4. Review by the Regulatory Authorities
After successfully completing phase III of a clinical trial, the drug enters the FDA review phase. This review phase involves a team of experts carefully evaluating all the findings obtained from clinical research. The review team comprises medical officers, statisticians, pharmacologists, chemists, and other specialists. These professionals work in unison to make decisions regarding the drug’s approval or rejection.
FDA review ensures a high-quality analysis of the clinical research study findings. This helps maintain consistent manufacturing and meets high-quality standards. Regulatory agencies also review the drug’s labeling to ensure accurate information for healthcare professionals and patients.
5. Post-Market Safety Monitoring
Safety monitoring, even after the approval of a drug, is quite essential. Manufacturers are obliged to carry out the Post-Market Safety Monitoring program to identify any potential risks associated with the medicine in patients. Manufacturers run therapeutic monitoring and pharmacovigilance programs to detect the types, frequency, and severity of the side effects associated with the medicines. Such information allows us to understand the implementation of the safety precautions, contraindications, and labeling requirements.
Regular facility inspections guarantee high manufacturing standards, and regulatory teams oversee whether the drug meets the requirements. This process ensures that only safe and effective treatments make it to patients, providing confidence that new medications have undergone rigorous testing before reaching the market.
Conclusion
The drug development process is complex and challenging. Every phase, from identifying compounds, conducting clinical trials, or undergoing FDA review, is designed specifically to issue the safest and most efficient drugs in the market. The future of drug development holds immense promise, and with continuous research and technological advancements, we can expect even more efficient and targeted treatments to emerge.