| Drug development pipelines are plagued by increasing costs and decreasing
productivity, so techniques that weed out poorly performing compounds early in
development are urgently needed. Microdosing studies can potentially provide
information about drug behaviour in humans before Phase I, but there have been
concerns that such small doses do not reflect a drug’s activity at the therapeutic
dose. Now there is growing evidence that microdosing studies are useful
for many drug types.
The number of new drugs reaching the market has been falling
over the last 20 years, while research and development costs
have progressively increased. This is partly due to inefficiencies
in the drug development process – only one in around 5,000
compounds entering drug development makes it from the
bench to the bedside (1). Poorly performing drug candidates
are discarded at all stages in the development process, but late
stage failures are particularly expensive, since the drug has been
developed through the preclinical and early clinical trial stages.
The most costly failure occurs when a drug reaches the market,
but has to be withdrawn. It costs more than $800 million to
develop a drug and more than $125 million to take a drug
through Phases I, II and III. The costs increase at later stages,
since a Phase III trial can involve thousands of patients spread
across several different countries (2). If a drug fails at this point,
the financial consequences will be considerable.
Early identification of drugs unlikely to succeed during
clinical trials can create significant cost savings, improve
pipeline productivity and mitigate risk. For example, the cost of
an approved new drug would fall by 4.7 per cent if just 25 per
cent of failures in Phase II were detected at Phase I instead (3). INTRODUCING MICRODOSINGThe risk of failure during the expensive clinical trial stages
can be reduced by collecting important information about a
drug’s behaviour before Phase I so that unpromising candidates
can be identified early. One critical attribute of a drug is... |
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