Proxalutamide Significantly Accelerates Viral Clearance and Reduces Time to Clinical Remission in Patients with Mild to Moderate COVID-19: Results from a Randomized, Double-Blinded, Placebo-Controlled Trial

Background The entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into type II pneumocytes is dependent on a modification of viral spike proteins by transmembrane protease serine 2 (TMPRSS2) expressed on the surface of human cells. TMPRSS2 is regulated by the androgen receptor, hence, SARS-CoV-2 infectivity is indirectly dependent on androgenic status and phenotype. Previously, we have reported that men affected by androgenetic alopecia (AGA) are overrepresented in severe coronavirus disease 2019 (COVID-19). Additionally, we have reported that men taking antiandrogenic drugs, e.g., 5-alpha-reductase inhibitors (5ARis), are less likely to have severe COVID-19. Here we aimed to test whether the androgen receptor antagonist, Proxalutamide, would be a beneficial treatment for subjects with SARS-CoV-2 infection. Methods Male and female subjects were recruited to a double-blinded, randomized, prospective, investigational study of Proxalutamide for the treatment of COVID-19. Mild to moderate, non-hospitalized subjects, who were confirmed positive for SARS-CoV-2, were treated with either Proxalutamide 200 mg/day or placebo. Endpoints for the study were remission time (days) and the percentage of subjects confirmed negative for SARS-CoV-2 on Day 7 after treatment. A negative SARS-CoV-2 test was defined by concentration-time (Ct)>40 determined by real-time reverse transcription-polymerase chain reaction (rtPCR). Results Two-hundred thirty-six (2360 subjects were included in the study (108 female, 128 male); 171 were randomized to the Proxalutamide arm and 65 were in the placebo group. On Day 7, SARS-CoV-2 became non-detectable with rtPCR (cT>40) in 82% of the subjects in the Proxalutamide group versus 31% in the placebo group (p < 0.001). The average clinical remission time for patients treated with Proxalutamide was 4.2 ±5.4 days versus 21.8 ±13.0 days in the placebo arm (p < 0.001). Conclusion Proxalutamide significantly accelerated viral clearance on Day 7 in mild to moderate COVID-19 patients versus placebo. Further, the time to clinical remission was significantly reduced in patients treated with Proxalutamide versus placebo.