Spero Therapeutics Inc. said its drug SPR206, which treats urinary tract infections and other drug-resistant bacterial strains, received the U.S. Food and Drug Administration's qualified infectious disease product designation.

The designation encourages the development of antibiotics for serious infections, with incentives including a five-year extension of exclusivity and the possibility of priority review.

In addition to urinary tract infections, SPR206 was granted the designation for the treatment of hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. The two types of pneumonia are the most common infections originating in hospitals and are associated with high rates of antibiotic-resistant pathogens.

The Cambridge, Mass.-based company's therapy, which is being developed to combat multi and extensively drug-resistant bacterial strains, is expected to enter a phase 1 clinical trial in 2019.