Sanofi Pays Rib-X $10M Up Front as Part of Antibiotics Collaboration

Deal centered on RX-04 program aims to develop compounds against Gram-positive and Gram-negative drug-resistant pathogens.

Sanofi is paying Rib-X Pharmaceuticals $10 million up front as part of an exclusive worldwide research collaboration and license option agreement for antibiotics resulting from Rib-X’ RX-04 program against drug-resistant Gram-positive and Gram-negative pathogens. The RX-04 program targets bacterial ribosomes, and has already led to the discovery of new classes of compounds that Rib-X claims have demonstrated preclinical efficacy at low, single doses against a number of multidrug resistant bacteria. Under terms of the deal Sanofi has rights to develop multiple products.

Rib-X will receive an additional $9 million in near-term research-based milestones, and could earn up to another $86 million in development and regulatory milestones, plus over $100 million in commercial milestones, on a per-product basis. Rib-X retains a co-promotion option in the U.S. on one of the molecules emerging from the collaboration.

Antibiotics firm Rib-X is exploiting its discovery platform to identify and optimize compounds that target the bacterial ribosome and bypass antibiotic-resistance mechanisms. The integrated platform combines computational analysis, x-ray crystallography, medicinal chemistry, microbiology, and biochemistry, allowing the visualization of drug candidate-ribosome binding.  Predictive computational approaches then quantify these interactions and assess the molecular properties of potential new drug candidates, facilitating the design of antibiotics with improved drug-like properties and activity against drug-resistant infections.

Rib-X claims its approach has a number of advantages over traditional drug discovery engines, including the ability to redesign existing antibiotic classes to circumvent resistance mechanisms, the design of novel antibiotic classes with desired ADME properties, and the customization of candidates against a specified spectrum of bacteria.

Rib-X’ pipeline is headed by the clinical-stage candidate delafloxacin (RX-3341), a next-generation quinolone, and radezolid (RX-1741), which has been developed through the firm’s in-house oxazolidinone program. Delafloxacin has demonstrated activity against MRSA, and completed a Phase II trial against complicated skin and soft tissue infections (cSSTI). RX-1741 has completed two separate Phase II studies for the treatment of community acquired pneumonia, and uncomplicated skin and soft tissue infections.

Two additional programs are at the discovery stage. RX-02 is focused on the development of a next-generation macrolide to treat uSSTI. The RX-04 program is centered on designing a chemical scaffold that can be used in the hospital for the treatment of serious hospital Gram-negative infections.