Summit Therapeutics PLC (LON:SUMM) (NASDAQ:SMMT) has found that its antibiotic Ridinilazole can kill C.difficile infections while preserving healthy microorganisms in the gastrointestinal tract.

Presenting data from phase II clinical trials, the company said the key findings were that the drug demonstrated higher efficacy than standard antibiotics while preserving the diversity of the gut microorganisms.

READ: Summit Therapeutics shares rise on phase II c.difficile data

A hundred patients were tested in this trial, with half receiving Ridinilazole and the others administered with vancomycin, the standard antibiotic used for C.difficile infections.

C.difficile infections (CDIs) can cause inflammation of the gut and severe diarrhoea and can be fatal in the most serious cases, while standard broad-spectrum antibiotics like vancomycin kill the ‘good’ bacteria and leave an adverse ratio gut chemicals that Summit says can favour the regrowth of infections.

By leaving patients’ normal gut bacteria unharmed, the focused treatment allows the body to convert existing bile acids into molecules that will prevent the infections from reoccurring.

By the end of phase II, the patients treated with Ridinilazole had a healthy set of bile acids, supporting the initial clinical data expecting a positive response to the drug.

“The damaging effect of broad-spectrum antibiotics in the treatment of CDI is far-reaching from the make-up and function of the gut microbiome through the poor clinical outcomes seen in one-third of patients, driven by a high rate of disease recurrence,” said David Roblin, President of research and development at the AIM-listed firm.

“Ridinilazole has the potential to be a targeted CDI treatment that could result in significantly better patient outcomes for the over half million US patients per year who have an episode of CDI. These latest data help to put the science behind the function of a healthy microbiome into context and highlight its importance in sustaining CDI cures.”

Shares were unchanged at 28p on Monday afternoon.