(Reuters) - An anti-inflammatory drug being developed by Corbus Pharmaceuticals Holdings as an add-on treatment for cystic fibrosis demonstrated promising safety and was well tolerated in a small midstage study, according to data released by the company on Thursday.

There were no serious adverse side effects deemed by researchers to be related to the drug, anabasum, in the 16-week, dose-escalating study of 85 adults with cystic fibrosis, the company reported.

Anabasum, given orally, showed a dose-dependent reduction in number of acute pulmonary exacerbations requiring intravenous antibiotics compared to placebo in the trial.

Patients who got the highest dose of anabasum, 20 milligrams twice per day, had a 75 percent reduction in the annualized rate of acute pulmonary exacerbations compared with those who got a placebo, the company said.

Serious pulmonary exacerbations often require hospitalization and can speed up loss of lung function.

CF, which affects about 75,000 people worldwide, is a life-shortening genetic disease in which the airways become blocked with thick mucus, leading to progressive lung damage and loss of function.

The company did not provide lung function data from the Phase II study, but several biomarkers related to inflammation found in sputum were reduced in patients on anabasum compared with the placebo group.

Most patients in the study were already taking Orkambi, a combination drug from Vertex Pharmaceuticals that improves lung function by addressing the underlying cause of CF.

But reducing inflammation may play a role in improving disease symptoms and patient outcomes, researchers believe.

“The finding of reduction in acute pulmonary exacerbations along with reductions in inflammatory cells and pro-inflammatory mediators demonstrate the potential of anabasum as a new therapeutic with a unique mechanism of action in cystic fibrosis,” Dr. James Chmiel, the study’s primary investigator from Rainbow Babies and Children’s Hospital in Cleveland, said in a statement.

The Vertex drugs, Kalydeco and Orkambi, work in CF patients with specific genetic mutations. Anabasum could potentially be used in all CF patients regardless of the variety of genetic mutation.