Drug Development and Pre-Authorisation Pharmacovigilance

How Medicines are developed in the European Uniontesting into 1,500 patients though it can include up to
and how their safety is monitored.several thousand. Here the focus is to demonstrate
This is a brief introduction to the complexthe efficacy of the product as well as showing
environment in which are developed within the EUacceptable safety in the population that will be using
and how their safety is monitored. Most of thethe drug. Where a drug will be given for long periods
information can be applied generally across the worldof time, long-term studies will be carried out. When
but the focus here is on the way it works in the UKthis program finishes, the registration dossier is
and the European Unionassembled and submitted to regulatory authorities.
How drugs are developed.The registration dossier is called the application for
Once candidate molecules have been selected formarketing authorisation (MAA in Europe, NDA in the
development they go through a program ofUS) and is usually submitted electronically. The paper
pre-clinical and clinical research which will hopefully endcopy of the pharmaceutical, pre-clinical and clinical files
in an application for marketing authorisation. The vastoften comprises many hundreds of volumes of data,
majority of molecules fail to complete the course: aseach volume comprising several hundred pages.
few as 1 in 10,000 of the molecules entering theDuring the registration review period the clinical trials
program will be suitable to pass the entirewill usually continue.
programme and reach the market.Phase 4: This is the post-marketing phase and any
Pre-clinical researchtests, trials or reviews once the marketing
Initially the molecules are tested in a researchauthorisation has been granted, are usually referred
program of animal, ex vivo and in vitro experimentsto as Phase 4 studies. These can be both
as required by the rules laid out in detailed regulatoryinterventional studies and observational studies
guidelines. These guidelines demand that somelooking at the pharmacoepidemiological statistics.
short-term animal studies have to be carried outEvery step and every part of every step in the
before the substance can be tested in single doses inclinical research program is heavily regulated. So prior
humans. These animal studies comprise: toxicologyto the drug first being tried in humans the regulatory
studies - working out what are the effects of largeauthorities will carry out an assessment all the animal
doses; pharmacology studies - looking at the effectsand in vitro studies. Every trial after this first
of the substance on how the body systems function;assessment will have to be approved by the
and pharmacokinetic studies - investigating how theappropriate regulatory authorities and separately by
substance is absorbed, distributed, metabolised andethics committees in each country. The assessments
eliminated in animals.of the regulatory authorities will be based on
The law then requires longer term animal toxicologysummaries of the available evidence to date. All of
studies to be carried out before multiple doses canthe new relevant safety information from animal
be given to humans, lengthening the periods ofstudies has to be submitted to the authorities and to
exposure and using a larger range of animals as thethe ethics committees during the clinical research
exposure in humans increases during the clinicalprogram and if the results come through once
research.marketing authorisation has been granted, the results
In addition to and at the same time as the animalmust go to the regulatory authorities.
pre-clinical studies, other studies are carried out forThe pharmaceutical company then creates an
example mutagenicity studies (looking at effects oninvestigator brochure which is a summary of all the
chromosomes and on genetic processes), studies ofknowledge about the drug, its safety, its efficacy
the effects on the foetus etc. as well as extensiveand anything else known about the drug. The
tests on tissue cultures, using computer modelling andcompany must then keep this document updated at
other tests which don't require a live organism.intervals and supply a copy to any investigators,
The rolling program of pre-clinical studies will beethics committees and regulators.
synchronised with the clinical study program so thatWhen unexpected serious adverse reactions occur
at every step in the clinical trial program, there willduring clinical trials that might have been related to
have been reassuring information from animal studies.the study drug (SUSARs), full details of them must
In fact even when it comes to the time applying forbe sent to the regulatory authorities within short time
a marketing authorisation, there may be ongoingframes as set out in the various rules - these are
long-term animal studies - usually cancer studies -called expedited reports. Comprehensive reports of
whose results might only become available after thethese SUSARs also have to be sent to any
product is on the market.investigators and to ethics committees working with
Clinical researchthe trial substance. Every year while the clinical trial
Clinical trials in humans go through four phases:program is running, annual reports (Annual Safety
Phase 1: This will usually consist of up to around 100Reports in the EU, IND Annual reports in the US)
subjects, investigating the tolerability of increasingwhich include a summary and analysis of all the
single doses of the drug and looking at itsserious adverse events that occurred during that
pharmacology and pharmacokinetics.period and any new safety findings from animal
Phase 2: This will usually include the first studies ofstudies, as well as evaluations of benefit and risk,
efficacy in patients with the disease and studies -must be submitted to the regulatory authorities and
usually in a few hundred patients - to find a doseethics committees. The submission of these
that is both effective and well-tolerated. Phase 1documents is required by law and companies are
studies sometimes continue concurrently alongsidemonitored to see if they are complying by a
phase 2 studies.combination of internal company audit and regulatory
Phase 3: This will usually be an extension to theauthority inspection.