**8. Conclusions**

Finding new drugs for the treatment of tuberculosis has been and continues to be a challenge despite the increased efforts over the last two decades. Lead generation approaches for MTB drug discovery have undergone several changes, mostly driven by an increased understanding of the biology of the pathogen, as well as the rapidly expanding knowledge on the biology of the interaction of the pathogen with the human host. This review chronicles the advances in a systematic study, starting from 'serendipitous discovery to phenotypic screening'. The technological advance mirrors the increased understanding of the biology of the pathogen. Interestingly, much of this increased understanding is also a consequence of the introduction of newer drugs for the treatment of tuberculosis.

**Author Contributions:** The authors contributed to the review in the following manner: Original idea of writing review (T.S.B., B.B. and R.K.S.), Conceptualization and frame work of the article (T.S.B., R.K.S., B.B. and J.B.), Data analysis (B.B., R.K.S. and J.B.) writing of review (T.S.B., B.B. and R.K.S.), data curation and editing (B.B., R.K.S. and J.B.) and writing of the article (T.S.B., B.B., R.K.S. and J.B.). All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest. All AstraZeneca results discussed in this paper are from published sources and available in the public domain.

## **References**


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