(NEXSTAR) — Drug manufacturer Pfizer announced Tuesday that it had begun testing an oral COVID-19 treatment. The antiviral treatment would be the first of its kind in the fight against coronavirus.

The Phase 1 study will be tested on healthy American adults “to evaluate the safety and tolerability of an investigational, novel oral antiviral therapeutic” for the virus that causes COVID-19, the company said in a press release.

The company is also testing an intravenous antiviral to treat COVID-19.

The treatments rely on protease inhibitors, the technology that’s also used to treat HIV and hepatitis C. Protease inhibitors work by binding to a viral enzyme, called a protease, and preventing the virus from replicating within the cell.

The treatments would be taken at the first sign of infection and would not require that patients be hospitalized or in critical care.

“Tackling the COVID-19 pandemic requires both prevention via vaccine and targeted treatment for those who contract the virus,” said Mikael Dolsten, MD, PhD., Chief Scientific Officer and President, Worldwide Research, Development and Medical of Pfizer, in a statement. “Given the way that SARS-CoV-2 is mutating and the continued global impact of COVID-19, it appears likely that it will be critical to have access to therapeutic options both now and beyond the pandemic.”