Once a lead compound has been identified, the drug development begins to bring a new pharmaceutical drug to the market. The process of drug development includes the preclinical study in vitro and in vivo, investigational new drug (IND) application, and clinical trial development to market the drug. The entire process is characterized by high attrition rates, large capital expenditures, and long timelines, which typically takes more than a decade and $1.8 billion. The overall failure rate in drug development is now more than 96%, including a 90% failure rate in clinical development.
Fig.1 Phases of drug development (Tamimi, 2009)
Drug development is beginning with drug discovery, which is the process of bringing a novel drug from “bench to bedside”. A promising drug must go through rigorous testing to prove it is enough safe and effective to reach a patient. The key milestones in drug development include preclinical research, Investigational New Drug Application (IND), Phase 1-3 clinical trials, FDA New Drug Application (NDA) approval, and subsequent Phase 4 clinical research. From concept to drug approved typically takes more than a decade.
Preclinical research is a key step in the development of new disease treatments, which decides whether a drug is ready for clinical trials. During the preclinical stage, testing includes in vitro and in vivo toxicity of candidates, pharmacokinetics, biomarker analysis, the pharmacology of absorption, distribution, metabolism, and excretion (ADME), etc. If the candidates meet the effectiveness and safety in disease models, they can enter into clinical trials. The preclinical studies provide enough drug toxicological data to support their potential safety in humans before clinical trials can begin. The no observable adverse effect levels (NOAELs) are used to guide the implementation of subsequent clinical phases.
Fig.2 Clinical Trial Phases
The next step is to select the promising drug for clinical trials. The pharmaceutical companies need to submit the file for IND. Once the FDA approved, the clinical trials will begin. Typically, the FDA requires Phase I, II, and III trials to determine if the drug can be approved for use. After the Phase 3 studies, the pharmaceutical company can subject an NDA to the FDA. The NDA is consisted of over 100,000 pages of material, including all the results of the research, proposed labeling, safety updates, drug abuse information, patent information, directions for use, institutional review board compliance information, and any data from studies that may have been conducted outside the United States. Base on the all-relevant components, the FDA review team will determine whether or not to approve the drug. The process may take 6-10 months. After approval by the FDA, the new drug can be sold and FDA may require additional research or data collection (post-marketing studies).
Tamimi, N. and Ellis, P., 2009. Drug Development: From Concept to Marketing. Nephron Clinical Practice, 113(3), pp.c125-c131.
For Research Use Only