Drug development: the way of medicine from lab to shelf

Drug development is the process of bringing a new pharmaceutical drug to the market once a lead compound has been identified through the process of drug discovery. Before a drug is deemed suitable for patients, it has to go through rigorous testing and cost-effectiveness analyses. Drug discovery cycle schematic: Each year sees a couple of dozen new drugs licensed for use, but in their wake there will be tens of thousands of candidate drugs that fell by the wayside. The research and development journey of those new drugs that make it to market will have taken around 12 years and cost around £1.15bn. New chemical entity development Broadly, the process of drug development can be divided into preclinical and clinical work. Pre-clinical New chemical entities (NCEs, also known as new molecular entities or NMEs) are compounds that emerge from the process of drug discovery. These have promising activity against a particular biological target that is important in disease. However, little is known about the safety, toxicity, pharmacokinetics, and metabolism of this NCE in humans. It is the function of drug development to assess all of these parameters prior to human clinical trials. A further major objective of drug development is to recommend the dose and schedule for the first use in a human clinical trial ("first-in-man" [FIM] or First Human Dose [FHD]). In addition, drug development must establish the physicochemical properties of the NCE: its chemical makeup, stability, and solubility. Manufacturers must optimize the process they use to make the chemical so they can scale up from a medicinal chemist producing milligrams, to manufacturing on the kilogram and ton scale. They further examine the product for suitability to package as capsules, tablets, aerosol, intramuscular injectable, subcutaneous injectable, or intravenous formulations. Together, these processes are known in preclinical and clinical development as chemistry, manufacturing, and control (CMC). The information is gathered from this preclinical testing, as well as information on CMC, and submitted to regulatory authorities (in the US, to the FDA), as an Investigational New Drug (IND) application. If the IND is approved, development moves to the clinical phase. Clinical phase Clinical trials involve three or four steps: Phase I trials, usually in healthy volunteers, determine safety and dosing. Testing with a small group (generally 20-80 people) Phase II trials are used to get an initial reading of efficacy and further explore safety in small numbers of patients having the disease targeted by the NCE. Testing with a larger group (generally several hundred people) Phase III trials are large, pivotal trials to determine safety and efficacy in sufficiently large numbers of patients with the targeted disease. Testing with an even larger group (generally 300-3,000 people) If safety and efficacy are adequately proved, clinical testing may stop at this step and the NCE advances to the new drug application (NDA) stage. Phase IV trials are post-approval trials that are sometimes a condition attached by the FDA, also called post-market surveillance studies. The process of defining characteristics of the drug does not stop once an NCE begins human clinical trials. In addition to the tests required to move a novel drug into the clinic for the first time, manufacturers must ensure that any long-term or chronic toxicities are well-defined, including effects on systems not previously monitored (fertility, reproduction, immune system, among others). They must also test the compound for its potential to cause cancer (carcinogenicity testing). If a compound emerges from these tests with an acceptable toxicity and safety profile, and the company can further show it has the desired effect in clinical trials, then the NCE portfolio of evidence can be submitted for marketing approval in the various countries where the manufacturer plans to sell it. In the United States, this process is called a "new drug application" or NDA. Cost The full cost of bringing a new drug (i.e., new chemical entity) to market – from discovery through clinical trials to approval – is complex and controversial. Typically, companies spend tens to hundreds of millions of U.S. dollars. One element of the complexity is that the much-publicized final numbers often not only include the out-of-pocket expenses for conducting a series of Phase I-III clinical trials, but also the capital costs of the long period (10 or more years) during which the company must cover out-of-pocket costs for preclinical drug discovery. One 2010 study assessed both capitalized and out-of-pocket costs for bringing a single new drug to market as about US$1.8 billion and $870 million, respectively. In an analysis of the drug development costs for 98 companies over a decade, the average cost per drug developed and approved by a single-drug company was $350 million. But for companies that approved between eight and 13 drugs over 10 years, the cost per drug went as high as $5.5 billion, due mainly to geographic expansion for marketing and ongoing costs for Phase IV trials and continuous monitoring for safety. Success rate Candidates for a new drug to treat a disease might, theoretically, include from 5,000 to 10,000 chemical compounds. On average about 250 of these show sufficient promise for further evaluation using laboratory tests, mice and other test animals. Typically, about ten of these qualify for tests on humans. A study conducted by the Tufts Center for the Study of Drug Development covering the 1980s and 1990s found that only 21.5 percent of drugs that started Phase I trials were eventually approved for marketing. In the time period of 2006 to 2015, the success rate was 9.6%. The high failure rates associated with pharmaceutical development are referred to as the "attrition rate" problem. Careful decision making during drug development is essential to avoid costly failures. In many cases, intelligent programme and clinical trial design can prevent false negative results. Well-designed, dose-finding studies and comparisons against both a placebo and a gold-standard treatment arm play a major role in achieving reliable data. For every 25,000 compounds that start in the laboratory, 25 are tested in humans, 5 make it to market and just one recoups what was invested. The high cost of current drug development coupled with the trend towards complex medicines and use of genomic markers to predict drug response (personalised medicines) may mean that, in the future, we see a more flexible drug development process and regulatory framework. Novel initiatives to boost development Novel initiatives include partnering between governmental organizations and industry. The world's largest such initiative is the Innovative Medicines Initiative (IMI), and examples of major national initiatives are Top Institute Pharma in the Netherlands and Biopeople in Denmark. In 2004, the FDA created the “Critical Path Initiative” to guide the new drug development process. In 2012, the Food and Drug Administration Safety and Innovation Act created the breakthrough therapy designation. References https://en.wikipedia.org/wiki/Drug_development https://www.fda.gov/patients/learn-about-drug-and-device-approvals/drug-development-process https://www.pharmaceutical-journal.com/publications/tomorrows-pharmacist/drug-development-the-journey-of-a-medicine-from-lab-to-shelf/20068196.article?firstPass=false By Aliyev F.