Introduction and Background of the Project

Introduction

The Hit-to-Lead collaboration between Astellas and TB Alliance is a continuation of an earlier screening project between the two organizations. The screening project, which involved screening Astella’s selected compound library, yielded promising hits resulting in the selection of series for further evaluation. This project extends the collaboration between Astellas, TB Alliance, and GHIT to develop a hit-to-lead phase for identifying potential candidates for the subsequent lead optimization phase.

Project objective

Astellas in collaboration with TB Alliance have identified two chemical series in our screen of the 20,000-compound library offered by Astellas.  We intend to develop them in a hit-to-lead phase by preparing a set of analogues for each to finetune their structure-activity relationships (SAR) and to acquire data on their pharmacokinetic (PK) properties and safety profiles. Consolidating the cumulative data, we aim to identify candidate compounds, ideally from both series, to test in a mouse acute infection model of TB. If successful, this project will provide a candidate for the lead optimization (LO) phase. 

Project design

New analogues in the two series will be synthesized and tested for the in vitro activity against Mtb and any promising analogues will be evaluated for PK and toxicity. Analogues selected after the PK and toxicity studies will be scaled up to test them in a mouse acute infection model.

How can your partnership (project) address global health challenges?

Tuberculosis (TB) is a global disease, found in every country in the world. It is the leading infectious cause of death worldwide. The World Health Organization estimates that 1.8 billion people—close to one quarter of the world's population—are infected with Mycobacterium tuberculosis (Mtb), the bacteria that causes TB. Last year, 10 million fell ill from TB and 1.4 million died. TB is an airborne disease that can be spread by coughing or sneezing and is the leading cause of infectious disease worldwide. It is responsible for economic devastation and the cycle of poverty and illness that entraps families, communities and even entire countries. Among the most vulnerable are women, children, and those with HIV/AIDS. There is growing resistance to available drugs, which means the disease is becoming more deadly and difficult to treat. There were more than half a million cases of drug resistant TB last year.

New TB drug candidates are urgently needed to treat patients around the world and eliminate the global TB pandemic. Our project aims to identify novel compounds, which show promise and can be further developed as effective TB drugs.

What sort of innovation are you bringing in your project?

The two series on hand appear to be unique in their structures compared with any TB drugs in use or under development. They also appear not to share the mechanism of action with any of the standard TB drugs, which is important for the prospect of discovering new drugs active against drug-resistant strains of Mtb.  We will investigate the mechanism of action of the two series potentially to identify new targets for drug discovery. 

Role and Responsibility of Each Partner

TB Alliance will coordinate synthesis of analogues, testing against Mtb, and generating ADMET data while Astellas will contribute to the design of new analogues and interpretation of the data.

Decisions on the direction of the project will be made jointly between TB Alliance and Astellas.