to the long development time it has not had a reasonable opportunity to exploit the
patent. By the time the patent protection of most drugs expires, more therapeutically
effective drugs will have been licensed so lack of protection is not necessarily a
major concern.18.3.4 Marketing authorisation
When the Phase III clinical trials are complete, the sponsor must submit to the
regulatory authority, such as the MHRA or FDA, a New Drug Application (NDA) for
permission to market the drug. In the EU there is a mutual recognition approval
procedure coordinated by the EMEA through its Committee on Human Medicinal
Products (CHMP) whereby one member country assesses the application and seeks
to gain recognition in others. Applications for marketing authorisation must be
accompanied by large amounts of documentation supporting all the clinical trials
data that underpin the application. Marketing authorisation is granted on a risk–
benefit analysis basis. The authorities recognise that no drug is ever risk-free and their
task is to assess whether the balance of the evidence submitted by the company is in
favour of the benefits. Approval may take up to 2 years but the authorities do attempt
to accelerate the process for drugs that represent totally new therapies. In the UK, the
National Committee for Health and Clinical Excellence (NICE) has the additional
power to decide whether or not the National Health Service (NHS) will agree to make
a newly authorised drug available to UK patients. Decisions by NICE depend not only
on the drug’s novelty but also on the economic benefits ensuing from its use. This
latter criterion is particularly important in approvals for expensive new therapies such
as monoclonal antibodies and is an increasingly important factor in the clinical
acceptability for all new medicines in many countries.18.4 Suggestions for further reading
General texts
Anonymous (2007).Guidelines on the Practice of Ethics Committees in Medical Research with
Human Participants, 4th edn. London: Royal College of Physicians.
Crooke, S. T. (ed.) (2008).Antisense Drug Technology: Principles, Strategies and Applications, 2nd
edn. New York: CRC Press. (Gives a review of the mechanisms of action, pharmacokinetics and
therapeutic potential of antisense drugs in the context of a wide range of clinical conditions.)
Kshirsagar, T. (ed.) (2008).High-Throughput Lead Optimization in Drug Discovery. New York:
CRC Press. (Uses real examples to illustrate the application of the technique in modern drug
development.)
Rang, H. P. (ed.) (2006).Drug Discovery and Development: Technology in Transition. London:
Elsevier. (An in-depth coverage written in an authoritative style by experts from the
pharmaceutical industry.)Review articles
Cross, D. M. and Bayliss, M. K. (2000). A commentary on the use of hepatocytes in drug metabolism
studies during drug discovery.Drug Metabolism Reviews, 32 , 219–240.
Eichler, H.-G., Pinatti, F., Flamion, B., Leufkens, H. and Breckenridge, A. (2008). Balancing early
market access to new drugs with the need for benefit/risk data: a mounting dilemma.Nature
Reviews Drug Discovery, 7 , 818–826.734 Drug discovery and development