drugs by CDER at FDA, but the percentage of precision medicine drugs approved

annually was increased to 21%, 28%, 27%, 35%, 42% and 25% in 2014, 2015, 2016,

2017, 2018 and 2019, respectively. It is also important to observe that while the

percentage of approved precision medicine drugs decreased to 25% in 2019 as

compared to 42% in 2018, there were significant number of approvals of drugs for

non-cancer diseases (7 out of 11) in 2019. In this year, new therapies are approved,

where no prior treatment was available (FDA 2020).

Precision medicine development is increasing. These drugs, which target specific

genetic, molecular and cellular markers and provide patients with personalised

treatments, are highly attractive targets for drug developers. The precision medicine

approach has rational design, higher chances of success and better impact on patient

outcome. It is possible with next-generation sequencing and powerful molecular

information of patients through reverse translational approach and biomarkers.

This chapter includes not only the relevance of the precision medicine, but it also

explains the potential of novel biomarkers and reverse translational research for the

development of personalised medicines from the conception of idea to further

laboratory bench work based on experiments and outcomes of the clinical responses.

9.2

Reverse Translational Approach to Drug Discovery

and Precision Medicine Development

The drug discovery and development landscape are inundated with potential drug

candidates that have shown huge possible aptitude and effectiveness in preclinical

models but failed when administered to clinical trial subjects. Although these

failures are subjected to various reasons, one being the most pervasive causes

wherein the inability of preclinical models fails to recapitulate the human physiology

accurately and precisely. Owing to advances with both in vitro and in vivo models, it

is imperative to improve those towards a more definite and clearer model. Addition-

ally, it will be necessary to incorporate results obtained from human clinical trials,

which can establish the reason of different responses by different patients when

given a specific therapy. Such investigation and knowledge could guide researchers

to develop more relevant animal models. Additionally, by reflecting human physiol-

ogy, models can envisage clinical replies to drug treatments more exactly (Seyhan

2019).

It is a known fact that the cumulative knowledge acquired by studies conducted

jointly on humans and animals is considered to provide the scientific evidences and

technical capabilities for drug discovery. In addition to this, continuous progress in

molecular biology, for decoding the complete human genome, has been effective to

provide multiple opportunities for selecting new molecular targets (Day et al. 2009).

The use of technique of reverse translational approach by choosing biomarkers can

support conduct of mechanistic studies in cellular or animal models. Through this

approach, the researchers and clinical pharmacologists are expected to be exposed

not only to a new scientific evidence but also to novel opportunities for precision

medicine drug development and individualised treatment (Carvalho et al. 2014).

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R. K. Goyal and G. Aggarwal