China-headquartered global biopharmaceutical company Frontier Biotechnologies announced positive results from the Phase 1 clinical trial of its drug candidate, FB2001 – a small molecule inhibitor of coronavirus main protease (M^pro) – in healthy adult volunteers.

The data, presented at the poster session of the 11^th International Conference on Emerging Infectious Diseases (ICEID), showed FB2001 to be safe and well tolerated among trial participants. Adverse events reported during the trial were mostly mild-to-moderate in severity, with no significant differences observed between participants in the Chinese and American study centers. 

The key findings from the study are as follows:

• 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.

“FB2001 has demonstrated in vivo antiviral activity in the lung and brain tissue of SARS-CoV-2 mouse model without the need for pharmacokinetic boosting. Therefore, it holds great promise as a treatment for acute COVID-19 as well as long-COVID, both of which will be evaluated in further follow-up studies”, said Dr Jay Lalezari, MD, Medical Director of Quest Clinical Research in San Francisco. 

Frontier Biotechnologies is also developing a pulmonary formulation of FB2001 that could be used in out-patient setting for the treatment of mild Covid-19, as well as for post-exposure prophylaxis. When inhaled directly into the respiratory tract and lungs, the tissue concentration of FB2001 is much higher than that in plasma; hence, the onset of action and viral clearance could potentially be faster than that of oral therapy.