The US patent and trademark office have granted a "composition of matter" patent.
It gives a period of exclusivity for ridinilazole in the United States until at least December 1, 2029, with the possibility of being extended.
It's been a busy period for the firm and Glyn Edwards, chief executive, said: "This new patent grant in one of our potential major commercial markets substantially strengthens our intellectual property estate protecting our novel CDI antibiotic ridinilazole and supports our efforts to maximise the potential of this promising compound."
"We are focused on advancing our CDI and DMD programmes and today's news, combined with the recently announced expansion of our PhaseOut DMD trial, highlights their continuing excellent progress as we seek to have a meaningful impact on the lives of patients living with these serious diseases."
In a Phase 2 clinical trial, ridinilazole showed statistical superiority over vancomycin - the standard of care medicine - in rates of sustained clinical response, an endpoint that captures both initial cure and recurrence of the disease.
And earlier this week, shares rose after the FDA allowed the company to broaden the scope of its phase II clinical trial of its drug ezutromid, formerly SMT C1100, for Duchenne muscular dystrophy to trial sites in the US.
Summit shares added 0.38% to stand at 131p.