Pfizer
https://www.fool.com/investing/2021/08/03/this-could-be-pfizers-next-covid-blockbuster-and-i/
This Could Be Pfizer's Next COVID Blockbuster -- and It Isn't a Vaccine
https://clinicaltrials.gov/ct2/show/NCT04960202
Brief Summary:
The purpose of this study is to determine whether PF-07321332/ritonavir is safe and effective for the treatment of adults who are ill with COVID-19 and do not need to be in the hospital, but are at an increased risk of developing severe illness. Throughout the study period, provision will be made to allow study visits to be conducted at a participant's home or another non-clinic location if available. The total study duration is up to 24 weeks.