(Reuters) - Nabriva Therapeutics Plc shares nearly doubled in morning trading on Monday after the company said its experimental antibiotic for community-acquired bacterial pneumonia (CABP) met the main goal of a late-stage study.

The clinical trial, which was the first of two late-stage studies, showed that the company’s drug, lefamulin, was as effective as the commonly used antibiotic moxifloxacin.

Nabriva’s treatment belongs to a new class of antibiotics called pleuromutilins, which inhibit bacterial growth by binding to a specific site on the bacterial ribosome that is responsible for its protein synthesis.

Retapumulin, which is developed by GlaxoSmithKline Plc, was the first pleuromutilin to be approved for use in humans, but only for topical applications.

If Nabriva’s lefamulin manages to get the U.S. Food and Drug administration’s clearance after its second late-stage study, it would be the first pleuromutilin to be approved for oral or intravenous use.

The drug’s successful trial comes at a time when there is a pressing need for new antibiotics as patients build up resistance to older therapies.

Leerink Research analyst Paul Matties called the data solid and added that the drug had an approvable safety profile.

A similar rate of adverse events was observed in both the lefamulin and the moxifloxacin arm of the study, Nabriva said, adding deaths occurred with the same frequency in both groups of patients.

The company said it expected data from the second late-stage trial in spring 2018 and plans to file a priority review request with the FDA in the second half of 2018.

CABP is one of the most common infectious diseases and the leading cause of death from infections in the United States.

The company’s website shows that a mid-stage study of the drug for acute skin and skin structure infections has also been completed.

After hitting a high of $12.75, Nabriva’s shares were up 75 percent at $11.92 in morning trading on the Nasdaq.