Trends in Drug Development
In the last decade, pharmaceutical industry has been suffering from lower R&D productivity despite the increased expenditure (Figure 1).
According to 2010 annual report from KRPIA, in 2009, US pharmaceutical companies spent $ 45.8 billion on their R&D activities, which is almost double the spending in 1999, $ 22.7 billion.
However, over the same period, the number of new drug approvals from FDA decreased approximately by half—from 35 to 19. In this regard, the key issues of pharmaceutical industry are to increase the success rate of drug development and to develop the innovative technology for the purpose.
Especially, considering that most of the drug R&D has been failed by either the low efficacy or high toxicity, innovative technology for more effective drug target identification and drug toxicity evaluation is highly required.
Figure 1. The problem of current drug development- low success rate and high expenditure
The need for genome-wide drug On/Off-target discovery technology
Today, the technology for drug target identification stays in a rudimentary level where microarrary only provides a limited, indirect understanding about the pharmacological mechanism of drug targeting and the indirect targets which are involved in drug effects,
and has limitations to identify direct drug targets in cells. The fact that more than half of drug R&D failures are caused by either drug toxicity or lack of drug efficacy (Figure 2) indicates that the current evaluation systems have limitations to define the molecular
targets related to efficacy and toxicity of drug candidates and that a significant technical innovation is required for more precise drug target identification and drug toxicity evaluation systems in current drug discovery process.
Especially, in case of small molecule drugs which comprise the main class of NDAs, there have been cases of billion dollar compensation for the damages and the subsequent market withdrawal of the drug due to the drug toxicity even after FDA approval.
Therefore, the development of more effective drug toxicity evaluation system is now emerging as the most critical issue in the pharmaceutical industry.
Figure 2. The need for innovative drug target identification and drug toxicity evaluation technology
The most important thing to solve these problems is to define the drug On/Off- target precisely, which provides molecular insights for the drug effects such as efficacy and toxicity at the molecular level and enables to solve the efficacy/toxicity issues.
Furthermore, the information on detailed molecular targets is also applicable to almost all areas of drug discovery as follows, and is considered to play a pivotal role for the dramatic increase of the success rate of new drug discovery as well as drug repositioning/ rescuing from previously known drugs
- Drug target identification and MOA study
- Drug toxicity Evaluation
- Drug Repositioning/ Rescuing
- Natural drug target discovery
- Drug target-based drug design