Blacksmith Medicines has positioned its lead antibiotic candidate FG-2101 for human trials following successful completion of IND-enabling studies, marking a significant milestone in the development of novel treatments for drug-resistant Gram-negative bacterial infections. The first-in-class compound targets LpxC, a zinc-dependent metalloenzyme found exclusively in Gram-negative bacteria, using a proprietary non-hydroxamate chemistry approach.
Novel Mechanism Addresses Critical Unmet Need
FG-2101 is designed to selectively inhibit LpxC, a zinc-dependent hydrolase that is conserved across Gram-negative bacteria but absent in Gram-positive bacteria and human cells. This selectivity offers a significant therapeutic advantage, as inhibiting LpxC results in potent killing of Gram-negative bacteria while sparing protective Gram-positive bacteria residing in the gut microbiome that help deter opportunistic C. difficile infections.
"Metalloenzymes represent an important, but underdeveloped, class of therapeutic targets," said Seth Cohen, Ph.D., co-founder of Blacksmith Medicines and Distinguished Professor of Chemistry and Biochemistry at U.C. San Diego. "Blacksmith's innovative small molecule chemistry platform provides solutions to previously undruggable metalloenzyme targets including LpxC, a zinc-dependent metalloenzyme found only in Gram-negative bacteria."
Overcoming Historical Development Challenges
LpxC has long been recognized as an attractive and highly sought-after antibiotic target, but previous development efforts have been hampered by chemistry limitations. Other LpxC inhibitors evaluated by biopharma companies in the past relied on hydroxamic acid-based warheads, which yielded ineffective compounds suffering from poor drug-like properties. As a result, no approved therapeutics currently target LpxC.
Blacksmith's proprietary chemistry platform has overcome these historical limitations by developing novel non-hydroxamate inhibitors of LpxC that demonstrate safety and efficacy in animal models of Gram-negative infection. The compounds are capable of killing Gram-negative 'superbugs' where other antibiotics prove ineffective.
Development Timeline and Support
FG-2101 is being developed for both intravenous and oral routes of administration to treat Gram-negative bacterial infections, including drug-resistant strains. The compound is poised to enter human trials later this year, with the program currently supported under a contract with NIAID (75N93022C00060).
Proprietary Metalloenzyme Platform
The development of FG-2101 leverages Blacksmith's comprehensive metalloenzyme-targeting platform, which addresses the historical difficulty in drugging this diverse class of targets. Over 30% of known enzymes are metalloenzymes, covering all major enzyme classes including oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases.
The Blacksmith platform combines a large proprietary fragment library of metal-binding pharmacophores with a comprehensive database containing full characterization of the metalloenzyme genome, including functions, metal cofactors, and disease associations. The platform also features a first-of-its-kind metallo-CRISPR library of custom single guide RNAs and an industry-leading metalloenzyme computational toolkit for docking, modeling, and structure-based drug design.
Strategic Partnerships and Investment
Blacksmith has established strategic drug discovery collaborations with major pharmaceutical companies including Basilea Pharmaceutica International Ltd., Cyteir Therapeutics Inc., Eli Lilly and Company, Hoffmann-La Roche Ltd., and Zoetis LLC. The company has also secured non-dilutive federal funding agreements with CARB-X and NIH/NIAID, with investors including Lilly, Evotec A.G., MP Healthcare Partners, MagnaSci Ventures, and Alexandria Venture Investments.
