Principles and Practice of Pharmaceutical Medicine

will become marketed products, and among those
only about a half will produce financial returns that
are disproportionately higher than their costs of
development.
Despite the high risk and escalating costs to
develop new medicines, the benefits of pharmaceu-
ticals to human healthcare provide both financial as
well as humanitarian motivation to pharmaceutical
companies and to the individual drug discovery
scientists.

4.2 Designing a drug discovery

project

‘Chance favors the prepared mind.’ – Anon.

All drug discovery projects depend on luck to be
successful, but research and careful planning can
improve chances of success and lower the cost.
Project teams can streamline the discovery process
by using the tools that can lead to a discovery most
directly. These tools are drawn from therepertoires
of modern biology, chemistry, robotics and com-
puter simulations. In comparison with older pro-
cesses ofin vivoscreening of huge numbers of
molecules, however, these innovations have not
beenassociatedwithshorteningofthedevelopment

timeof7–10years(seeFigure4.1).Somethinkthat

modern biology as well as other fields have only

increased the numbers of ‘hits’ overall, whereas

others think that an increase in speed of discovery

has compensated foran increasein regulatorystrin-

gency during the last two decades.

The ‘Unmet Clinical Need’

as a market niche

Usually, scientists are directed to research new

targets in specific therapeutic areas based on

unmet clinical needs and market opportunities

that are foreseen in the medium-to-long term.

Both medical and business considerations are

weighed. Larger companies will rarely fund inter-

nal research for drug discovery of orphan drug

products (or products targeting diseases with few

patients). On the other hand, small market niche

needs are often sufficient for smaller companies

(often researching in biotechnology).

Once a medical need and market niche are iden-

tified, and a particular therapeutic area chosen, the

biological research begins. It is during this first

stage of drug discovery that anecdotal clinical

observations, empirical outcomes and ‘data’ from

folk medicine are often employed, if only as

direction-finding tools.

Bas ic

Research

Tar ge t

ID

Tar ge t

Va lidatio n

Assay

De ve l.

Screening Optimize ADM E/ To x

IND

Clinical

T ria ls

Market

Bas ic

Research

Tar ge t

ID

Tar ge t

Va lidatio n

Assay

De ve l. Screening Optimize

ADM E/ To x

IND

Clinical

T ria ls Market

2–7 years

5–10 years

Figure 4.1 The drug discovery process

44 CH4 DRUG DISCOVERY: DESIGN AND SERENDIPITY