An experimental HIV drug that has been used to successfully treat COVID-19 patients is in its second phase of testing with the Food and Drug Administration, its manufacturer says.

Leronlimab, made by the biotech company CytoDyn, was used to treat a handful of severely ill patients in New York City hospitals; a couple were able to be removed from their ventilators.

“With a study in China indicating the mortality rate among COVID-19 patients requiring mechanical ventilator at more than 85%, the world desperately needs a therapy that can help this patient population,” CytoDyn CEO Nader Pourhassan said in a statement.

Initial studies suggest leronlimab can reduce the overactive immune response, known as a cytokine storm, that can be triggered by the coronavirus infection. Cytokine storms can result in pneumonia and even death.

“[I] cried for about five minutes. It was very, very emotional,” Pourhassan told Seattle’s KIRO 7 News after first learning of the results. “We’re hoping we can save millions of lives.”