Novel Inhibitor for Treating Hospitalized Patients With COVID-19

Hospitalized patients are a vulnerable group that are exposed to pathogens that can lead to healthcare associated infections (HAIs). Of course, now there is the serious concern of these patients getting exposed to COVID-19.

Exposure to COVID-19 has been impossible to contain, and in such cases, having a therapy to minimize severity is important.

Existing therapies have had mixed results and in the ones that are performing better, such as Paxlovid, there is a need for people to take the medication sooner, and there is the “rebound” effect where patients test positive several days later after being on the medication.

Treatments to be utilized for patients in post-exposure situations continue to be explored.

One company, Frontier Biotechnologies, a China-based AIDS/HIV therapy manufacturer has developed an inhibitor, FB2001 (Bofutrelvir), a small molecule inhibitor of the main coronavirus protease being studied for use in hospitalized patients and to prevent COVID-19 following exposure.

The company already has an HIV antiviral that was approved by China’s federal regulatory body in 2018.

Frontier has developed two formulations: an intravenous modality and inhalation version.

Frontier performed a phase 1 study for FB2001, and announced its results earlier this year. In it, a total of 120 participants (80 White people in the United States and 40 Chinese people in China) received intravenous infusions of FB2001 at either single doses from 5 mg to 400 mg, or multiple doses of 30 mg to 400 mg daily for 5 days.

The findings from the study were the following:

• FB2001 was safe and well tolerated up to 400 mg per day
• Without using a pharmacokinetic enhancer, FB2001 exhibited plasma and lung drug concentration above the in vitro antiviral EC50 value.
• No significant difference was observed between Chinese and American populations.
• No serious adverse events or dose-limiting toxicities were reported.
• 24 grade 1 or 2 adverse events were observed

The company has since started a phase 2/3 study (BRIGHT trial) to enroll about 1200 hospitalized patients in clinical centers globally. "The phase 1 data were really promising," Frontier Biotechnologies Chief Medical Officer Michael Hu, MD, said in a statement. "And we are confident to carry out the pivotal trial to explore the utility of the drug in reducing the time to recovery in hospitalized patients due to COVID-19."

The company expects to have interim data analysis either by the end of this year or early part of 2023.

Frontier is also exploring the development of an inhaled formulation of FB2001 that could be used outside the hospital and that may increase drug concentrations in the lung.

Hu spoke to Contagion recently and the CMO spoke more about their investigational therapy’s mechanism of action, insights on its studies, and its potential place in the market.