Michael S. Kinch

An analysis of FDA-approved drugs: natural products and their derivatives

Natural products contribute greatly to the history and landscape of new molecular entities (NMEs). An assessment of all FDA-approved NMEs reveals that natural products and their derivatives represent over one-third of all NMEs. Nearly one-half of these are derived from mammals, one-quarter from microbes and one-quarter from plants. Since the 1930s, the total fraction of natural products has diminished, whereas semisynthetic and synthetic natural product derivatives have increased. Over time, this fraction has also become enriched with microbial natural products, which represent a significant portion of approved antibiotics, including more than two-thirds of all antibacterial NMEs. In recent years, the declining focus on natural products has impacted the pipeline of NMEs from specific classes, and this trend is likely to continue without specific investment in the pursuit of natural products.

An overview of FDA-approved new molecular entities: 1827-2013.

The pharmaceutical industry is undergoing fundamental change and its future is unclear. We performed a meta-analysis by cataloging FDA-approved legacy drugs and new molecular entities (NMEs). Objective information regarding scientific, medical and commercial activities was captured and provides insight into processes governing drug development. In this report, we review the rates of NME introduction through to the end of 2013. Recent trends show the emergence of a handful of companies that controls two-thirds of NMEs. We also report growth in the number of NMEs controlled by marketing organizations that have little or no internal drug discovery or development activities. This trend has increased dramatically since 2000 and could raise important questions about the future landscape and viability of drug discovery and development.

An overview of FDA-approved biologics medicines.

Recombinant DNA technologies revolutionized medicine. Herein, the approvals and mechanistic basis of biologics-based medicines are analyzed. The overall and relative rate of FDA approvals for recombinant proteins grew from the 1980s through the first half-decade of the new millennium. Over time, the number of biologics gaining approval for an orphan indication has climbed to more than 50% in the current decade. The field has been dynamic in terms of the types of biologics, indications targeted and the mechanistic basis of drug activity. Despite impressive increases in recombinant-protein-based medicine, the rate of new biologics approvals could have leveled out.

An analysis of FDA-approved drugs for infectious disease: antibacterial agents.

Drugs targeting infectious diseases have greatly improved public health. A study to evaluate all US Food and Drug Administration (FDA)-approved new molecular entities (NMEs) reveals that the number of new agents targeting infectious disease peaked during the 1990s and declined rapidly thereafter. Molecules targeting bacterial pathogens represent the most common component of anti-infectives followed by antivirals and antifungals. Focusing on antibacterial agents, an increase in new NMEs predominated from the 1960s through to the 1990s, dropping sharply thereafter. Obsolescence and resistance has eliminated one-third of these drugs. Consequently, the arsenal of antibiotics peaked in 2000 and is declining. Likewise, the number of organizations awarded at least one NME for a bacterial indication has declined to a level not seen in more than a half century.

An analysis of FDA-approved drugs for infectious disease: HIV/AIDS drugs.

HIV/AIDS is one of the worst pandemics in history. According to the World Health Organization, 26 million people have died since 1981 - 1.6 million in 2012 alone. The dramatic rise in HIV/AIDS mobilized a swift and impressive coordination among governmental, academic and private sector organizations to identify the virus and develop new treatments. Herein, we assess the arsenal of 28 new molecular entities (NMEs) targeting HIV/AIDS. These data demonstrate that the first approval of zidovudine presaged an expansion of the antiviral repertoire over the following years. Whereas the rate of HIV/AIDS NMEs is rapidly declining, so is the number of organizations developing NMEs. We speculate that decisions to abandon further research reflect, in part, growing costs and time required for development.

An analysis of FDA-approved drugs for oncology.

Cancer remains the second leading cause of death globally. The number of new medicines targeting cancer has grown impressively since the 1990s. On average, ten new drugs are introduced each year. Such growth has partly been achieved by emphasizing biologics and orphan indications, which account for one-quarter and one-half of new oncology drugs, respectively. The biotechnology industry likewise has become the primary driver of cancer drug development in terms of patents, preclinical and clinical research, although pharmaceutical companies are granted more FDA approvals. Many targeting strategies have been successful but recent trends suggest that kinase targets, although tractable, might be overemphasized.

The rise (and decline?) of biotechnology

Since the 1970s, biotechnology has been a key innovator in drug development. An analysis of FDA-approved therapeutics demonstrates pharmaceutical companies outpace biotechs in terms of new approvals but biotechnology companies are now responsible for earlier-stage activities (patents, INDs or clinical development). The number of biotechnology organizations that contributed to an FDA approval began declining in the 2000s and is at a level not seen since the 1980s. Whereas early biotechnology companies had a decade from first approval until acquisition, the average acquisition of a biotechnology company now occurs months before their first FDA approval. The number of hybrid organizations that arise when pharmaceutical companies acquire biotechnology is likewise declining, raising questions about the sustainability of biotechnology.

Trends in pharmaceutical targeting of clinical indications: 1930-2013.

An analysis of FDA-approved new molecular entities (NMEs) reveals trends in therapeutic applications. Four groupings (infectious diseases, cardiovascular diseases, autoimmune/inflammatory diseases and cancer) capture more than 60% of NMEs. Infectious diseases are the most targeted indications. Near the turn of the new millennium, the rate of new approvals for infectious diseases decreased. The absolute and relative number of NMEs targeting psychiatric, neurological and pain/itch indications also declined. By contrast, NMEs targeting cancer have risen in the past two decades as have NMEs targeting orphan indications. These results suggest the drug development community has largely been responsive to public health and market needs. However, finite resources might indicate emphasis on some unmet needs could come at the cost of others.

An analysis of original research contributions toward FDA-approved drugs

Academic researchers shaped the landscape of drug discovery for nearly two centuries, and their efforts initiated programs for more than half of the US Food and Drug Administration (FDA)-approved new molecular entities (NMEs). During the first 50 years of the 20th century, contributions from industry-based discovery programs steadily increased, stabilizing near half of all first publications for NMEs. Although academia and industry have made similar contributions to the discovery of FDA-approved NMEs, there remains a substantial difference in the gap-to-approval; on average, industry NMEs are 12 years closer to market at the time of the first publication. As more drug discovery efforts shift from industry to academia, including high-throughput screening resources, academia could have an increasingly crucial role in drug discovery.

Target selection for FDA-approved medicines.

The biopharmaceutical industry translates fundamental understanding of disease into new medicines. As part of a comprehensive analysis of FDA-approved new molecular entities (NMEs), we assessed the mechanistic basis of drug efficacy, with emphasis on target selection. Three target families capture almost half of all NMEs and the leading ten families capture more than three-quarters of NME approvals. Target families were related to their clinical application and identify dynamic trends in targeting over time. These data suggest increasing attention toward novel target families, which presumably reflects increased understanding of disease etiology. We also suggest the need to balance the ongoing emphasis on target-based drug discovery with phenotypic approaches to drug discovery.