https://www.nejm.org/doi/full/10.1056/NEJMoa2016638
The successful model is from Dr. Zelenko that has 3 elements; HCQ +(antibiotic +zinc) which works in combination in the first phase of COVID-19. The zinc (deficient in older people) prevents the virus from replicating and setting up the cytokine second phase. The HCQ acts as a ionosphere to allow the zinc into the invaded cell to attack the virus. The antibiotic alleviates the inflammation in the lungs. To that end cortisteroids work as well.
Even age-old Ivermectin is found to kill the virus in vitro. So any study that deviates from the successful model is going to fail. I can understand that, and I’m not a physician - but I was exposed to STEM, unlike the bulk of our population today.