The O'Neill report identifies antibiotic resistance as one of the most important issues threatening our way of life. The potential consequences of failure to address this threat are assessed as 10 million deaths per annum by 2050 at an economic cost of 100 trillion US dollars. This project addresses one of the most difficult to treat classes of bacterial pathogen which is becoming recalcitrant to almost all available therapeutic options - MDR Gram-negative bacteria. For these bacteria, a class of antibiotics called carbapenems was the mainstay of treatment until resistance to this class started to develop. An old antibiotic class called polymyxins, whilst rather toxic, was then revived to provide a somewhat imperfect stop gap. In treatment of viral diseases and even bacterial infections such as tuberculosis, it is accepted that combinations of drugs are needed for effective treatment. Cantab is proposing to develop an innovative combination of a novel low toxicity polymyxin derivative with a partner antibiotic which is able to provide effective coverage for even the most difficult to treat infections. Public support is needed to address the economic uncertainties of the antibacterial market and to help to secure the future of Cantab as a UK-based antibiotic developer.