Shanghai Ruijin Hospital recently announced that it has initiated an investigator-initiated clinical trial (IIT) to evaluate the safety and efficacy of Bofutrelvir administered by inhalation for post-exposure prophylaxis in close contacts of COVID-19 (NCT05415241).  It is a single-arm, open-label, multi-dose exploratory clinical study with an enrolment of ~60 subjects who are close contacts of COVID-19 patients.  Data from preclinical studies has shown that Bofutrelvir administered by inhalation is safe and tolerable in rats and dogs, and PK profile shown that Bofutrelvir has significant higher drug exposure in respiratory tract and lungs than that in plasma.

FB2001 (generic name: Bofutrelvir) is a SARS-CoV-2 3CL protease inhibitor under clinical development for hospitalized patients as well as for post-exposure prophylaxis of Covid-19.  It is a peptidomimetic compound targeting 3CL-protease based on three-dimensional crystal structure of the protease.  Preclinical data has shown it has potent activities in vitro and in vivo against SARS-CoV-2 variants such as Alpha, Beta, Delta, and Omicron.  Clinical data from two phase 1 trials conducted in the US and China has shown that Bofutrelvir is safe and tolerable with a PK profile (without using a booster like ritonavir) supporting further clinical development.  It is currently in a pivotal global phase 2/3 clinical trial for hospitalized Covid-19 patients.