Current and future sources of drugs

The discovery of drugs, initially empirical, has followed the evolution of medical understanding of human pathologies. Although certain drugs with undeniable therapeutic virtues, such as opium, have been known to us since Antiquity, it must be recognized that many of them were used without any real proof of efficacy. Signature medicine attributed a positive effect on the liver to remedies with a green, acidic taste. Glowworms were used in eye drops, beans were used to heal the kidneys, and yellow saffron was used to treat jaundice. The end of the 19th century saw the isolation of the first plant-derived active ingredients, including morphine, and the total synthesis of simple medicinal molecules such as aspirin. Building on this momentum, the chemistry of the early and mid-twentieth century led to the discovery of major classes of drugs that revolutionized patients' lives and are still used today: sulfonamides, antidepressants, neuroleptics...

The development of our knowledge of the role and structure of proteins, and of the phenomena governing drug-receptor interactions, at the end of the last century laid the foundations for the development of new, effective therapeutic compounds. While the advent of tissue biochemistry in the 1950s led to the development of non-steroidal anti-inflammatory drugs, it was cellular biochemistry which, in the late 1970s, led to the development of cancer therapies. Today, priority is given to molecular structure, which, combined with the creation of high-performance software, makes it possible to design new drug substances using computer tools. Nevertheless, the diversity of structures found in the plant and animal world remains a source of inspiration in the design of new drugs. Chemical synthesis and hemisynthesis remain indispensable tools, with a growing emphasis on green chemistry. In recent years, biotechnologies have made it possible not only to produce drugs that used to be extracted from animal organs (insulin from pigs, for example), but also monoclonal antibodies for a wide range of indications (oncology, rheumatology, immunology, allergology, etc.). Targeted therapies, meanwhile, are undergoing considerable development with a view to minimizing adverse effects on patients, with hopes based in this field on supramolecular chemistry and nanotechnologies, among others. Last but not least, the sequencing of the human genome is opening up new therapeutic possibilities for hereditary diseases.

The aim of this article is to use concrete examples from the main drug classes currently on the market to illustrate the main avenues for the discovery of new active ingredients and the techniques used. The evolution of research in this field and future prospects for therapeutic innovation are also presented in relation to the global economic...