• Novel class of antibiotics
• Bactericidal activity demonstrated in vitro and in vivo against broad range of Gram-negative bacteria, including multidrug-resistant strains

Dr. Laurenz Kellenberger, Chief Scientific Officer of Basilea, said: “The acquired antibiotics are of a novel class, targeting the lipopolysaccharide transport in Gram-negative bacteria, which have been highlighted by the World Health Organization as priority pathogens against which new antibiotics are urgently needed. The convincing potent and rapid bactericidal activity against bacteria such as Escherichia coli or Klebsiella pneumoniae, including multidrug-resistant species, and the activity in infection models, is very encouraging. We are excited by the addition of this new program to our growing pipeline and to continue the development of this targeted antibiotics class, which has the potential to address an unmet medical need in the treatment of severe bacterial infections in the hospital.”

The antibiotics were developed within Spexis’ Outer Membrane Protein Targeting Antibiotics (OMPTA) program and selectively disrupt the lipopolysaccharide transport bridge, an essential structure in Gram-negative bacteria. This results in a loss of the integrity of the outer cell membrane, intracellular accumulation of lipopolysaccharides and killing of the bacteria. Activity has been shown in vitro and in vivo against Enterobacteriaceae such as E. coli and K. pneumoniae, including strains resistant to beta-lactams and colistin, an antibiotic regarded as last-resort therapy. The program was funded in part by CARB-X (Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator).² This underscores the potential of this novel class of antibiotics. CARB-X is a global non-profit partnership dedicated to supporting early-stage antibacterial research and development, to address the rising threat of drug-resistant bacteria.

Basilea is acquiring all program compounds, know-how and intellectual property and is paying Spexis up to a total of CHF 2 million, which consists of an upfront payment, a payment related to the transfer of the assets to Basilea, and a potential final milestone payment related to the availability of near-term external funding for the further development of the program. In addition, Basilea assumes the rights and obligations of Spexis, including potential low single-digit percentage royalties on sales, under licensing agreements. The transaction is subject to the approval by the Western District Court of the Canton Basel-Landschaft.