Sanofi has linked up with the USA's Rib-X Pharmaceuticals to develop a new class of antibiotics.

The French drugmaker has signed a deal to licence antibiotics resulting from Rib-X’s RX-04 programme for the treatment of resistant Gram-positive and Gram-negative pathogens. That programme  has produced "entirely new families of compounds that have demonstrated efficacy at low, single doses in murine infection models", Sanofi notes.

Cashwise, Rib-X will pocket a $10 million upfront fee and is also eligible to receive up to an additional $9 million in near-term research-based milestones and will be eligible to receive further undisclosed payments depending on the success of the project. Specifically, the agreement could result in up to $86 million in development and regulatory milestones, while commercial fees could exceed $100 million for each drug. Rib-X has a co-promotion option in the USA on one of the molecules coming from the collaboration, while royalties "could reach low double digit figures".

Sanofi's R&D chief Elias Zerhouni said that "the clinical need for new antibiotics is reaching crisis level, yet the antibiotic pipeline is running dry and fewer and fewer companies are working to develop drugs in this space". Mark Leuchtenberger, Rib-X chief executive, noted that these "completely novel classes of antibiotics should lead to true breakthrough therapies".

He added that the agreement will enable Rib-X to "aggressively advance our clinical stage candidates, delafloxacin and radezolid, towards pivotal trials and support additional discovery-stage programmes like RX-05 and RX-06".