Gilead taps X-Chem’s DNA-encoded libraries for drug discovery

Gilead Sign
X-Chem will screen its DNA-encoded libraries to discover novel antivirals for Gilead.

Gilead Sciences has teamed up with privately held X-Chem, which will screen its DNA-encoded libraries containing over 120 billion small molecules, in the hope of finding new drugs in antiviral and other therapeutic areas.

X-Chem will receive an undisclosed upfront payment, and Gilead has the option to license drug leads for further development if it finds them to be promising. X-Chem is eligible for licensing fees and future milestone payments.

Compounds in X-Chem’s libraries are generated by iterative combinatorial synthesis with unique DNA tags attached to each one of them. When screened against a target of interest, promising molecules that binds to the target are picked out, and their structure information can be obtained based on synthetic history encoded in their unique DNA sequence. Chemicals synthesized through such technology can tackle some difficult targets such as PPI, ubiquitin ligase, epigenetic and antibacterial targets.

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The Gilead deal represents growing interests in DNA-encoded platform and X-Chem’s service in particular. Not long after X-chem’s foundation in 2009, PPD made a strategic move and acquired a controlling share in the Waltham, Massachusetts-based company, and upon expiration of that partnership in 2014, decided to exercise its option to buy it in full. Although X-Chem later spun out of PPD in 2016 based on a new strategic direction to pursue its biotech focus, it has already built a reputation in the industry.

Bayer, which again expanded its multitarget drug discovery collaboration with X-Chem in October, has previously licensed two programs from X-Chem, one against an epigenetic target and one in cardiovascular. On Oct. 31, X-Chem joined a research consortium picked to receive a research grant from the Department of Defense to discover new drugs against tuberculosis. It has also signed deals with U.S. and European companies Roche, AstraZeneca, Pfizer, Janssen, Sanofi, Alexion and Vertex, and with Astellas, Ono and Otsuka’s Taiho in Japan.