Summit Therapeutics Announces Preclinical Candidate and Associated CARB-X Funding Support for the Treatment of Infections Caused by Carbapenem-Resistant Enterobacteriaceae, a CDC Urgent Threat and WHO Critical Priority

Cambridge, MA, May 18, 2021 - Summit Therapeutics Inc. (NASDAQ: SMMT) announced today that it has selected a new preclinical candidate, SMT026738 (“SMT-738”), for development in the fight against multidrug resistant infections, specifically carbapenem-resistant Enterobacteriaceae (CRE) infections. Simultaneously, Summit has received an award from CARB-X to progress this candidate through preclinical development and Phase 1a clinical trials. The award commits initial funding of up to $4.1 million, with the possibility of up to another $3.7 million based on the achievement of future milestones.

SMT-738 is the first of a novel class of precision antibiotics with a new mechanism of action that acts via the bacterial target, LolCDE. SMT-738 has the potential to treat multidrug resistant infections caused by a large family of pathogenic Gram-negative bacteria, the Enterobacteriaceae, that include serious human pathogens such as Escherichia coli and Klebsiella pneumoniae. Combining a novel antibiotic class (SMT-738) with a clinically unexploited target (LolCDE) mitigates the risk of pre-existing resistance, potentially allowing for the effective treatment of Enterobacteriaceae-caused infections that currently have very limited and failing treatment options due to resistance to existing antibiotic classes.

“Our mission at Summit is to create patient- and societal-friendly medicinal therapies that improve the quality and duration of patients’ lives, while resolving serious unmet needs,” said Robert W. Duggan, Executive Chairman and Chief Executive Officer of Summit. “SMT-738 has the potential to save the lives of patients with as yet untreatable infections through a novel drug class with a low propensity for resistance development. We are excited and optimistic to take on the real challenge of antibiotic resistance and are grateful to CARB-X for partnering with us in support of this important mission.”

SMT-738 was discovered using Summit’s proprietary technology, our Discuva Platform, as a part of the DDS-04 series, and we retain worldwide clinical development and commercial rights to the compound. We expect to begin Phase 1 studies in 2023.

“With the growing threat of antibiotic resistance, particularly with respect to CRE infections, SMT-738 is clearly differentiated from all agents, including the beta-lactamase inhibitors, that are currently used to treat such infections,” adds David Powell, Ph.D., Summit’s Chief Scientific Officer. “By leveraging the transposon libraries of bacteria within our Discuva Platform, we have identified the target to be the clinically unexploited LolCDE complex, an essential lipid transport system in Gram-negative bacteria. SMT-738 has potent in vitro activity against clinical CRE isolates including difficult to treat metallo-beta-lactamase carrying strains encoding the New Delhi Metallo-beta-lactamase (NDM). Having encountered no existing resistance in clinical isolates to the novel chemistry of SMT-738, the ability of our drug molecule to reset the clock against growing resistance is critical in our collective fight against these pathogens causing an urgent public health threat.”