Pharma Focus Asia

Trends in clinical development timeframes for antiviral drugs launched in the UK, 1981–2014: a retrospective observational study

Authors : Derek J Ward, Edward Hammond, Luan Linden-Phillips, Andrew J Stevens



Recent decades have witnessed the development of highly innovative new antiviral drug therapies. However, there are concerns that rising costs and lengthening development times could have implications for future patient access to innovative new drugs. We sought to establish whether the time taken for the clinical development of new antiviral drugs launched in the UK had increased since the 1980s.

Design and setting Retrospective observational study of all new antiviral drugs licensed for use in the UK.

Primary and secondary outcome measures Duration of clinical development (from initiation of studies in humans to receipt of Marketing Authorisation), subdivided into clinical trial and regulatory approval periods by the date of Marketing Authorisation Application.


48 new antiviral drugs were licensed for use in the UK between 1981 and 2014 (inclusive), over half (54%) initially for HIV infection. The overall mean duration of clinical development was 77.2 months, of which 64.6 months was spent in clinical trials before regulatory submission. The total time in clinical development increased from 41.7 months for drugs licensed 1981–1992 to 91.7 months for drugs licensed 2004–2014. This increase was accounted for by an increase in the clinical trials period and not the regulatory approval period, for which there was no observable trend. Drugs initially licensed to treat hepatitis C had a longer duration of clinical development than those indicated for other viral infections. However, the, initially shorter clinical development durations of drugs indicated for HIV infection increased more rapidly across the study period than those indicated for other viral infections.


The time spent by antiviral drugs in clinical development has increased markedly in recent decades despite many initiatives to speed access to innovative new drugs. However, this represents only one part of the translational research pathway, and a complete picture of development timeframes is lacking.

Citation: Derek J Ward, Edward Hammond, Luan Linden-Phillips, Andrew J Stevens Trends in clinical development timeframes for antiviral drugs launched in the UK, 1981–2014: a retrospective observational study
BMJ Open 2015;5:e009333 doi:10.1136/bmjopen-2015-009333

Received: 7 July 2015 Revised: 28 August 2015 Accepted: 4 September 2015 Published: 16 November 2015

Copyright: This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See:


DJW and AJS conceived the original study idea, and EH and LL-P contributed to the development of the study design and methods. EH collected the data and carried out the analysis with assistance from LL-P and DJW. All authors (DJW, EH, LL-P and AJS) were involved in the interpretation of the results. DJW produced the initial draft of the paper, which was then circulated repeatedly to all authors for critical revision. DJW, EH, LL-P and AJS read and approved the final version. All authors had full access to all of the study data (including statistical reports and tables), and can take responsibility for the integrity of the data and the accuracy of the analysis. DJW is the guarantor.


The study was undertaken as part of the research programme of the NIHR Horizon Scanning Research & Intelligence Centre (NIHR HSRIC). HSRIC is funded by the National Institute for Health Research (NIHR). The NIHR had no role in the study design; in the collection, analysis and interpretation of the data; in the preparation of the manuscript; or in the decision to submit the article for publication. This article presents independent research funded by the NIHR. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

Competing interests

All authors have completed the ICMJE uniform disclosure form at and declare: all authors have financial support from the National Institute for Health Research (NIHR) for the submitted work; all authors have no financial relationships with any organisations that might have an interest in the submitted work in the previous 3 years; and all authors have no other relationships or activities that could appear to have influenced the submitted work.

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