We can check efficacy claim of HCQ by doing Randomised trail in US under FDA supervision instead of just relying on Chinese studies, But main benefit of HCQ if

We can check efficacy claim of HCQ by doing Randomised trail in US under FDA supervision instead of just relying on Chinese studies, But main benefit of HCQ if it found to be effective would be that it is already a widely used approved drug. We know it's side effects, Getting a new drug approved and check for its side effects itself is very time consuming and expensive exercise. Here only randomised large scale trail is needed. What is preventive USA Pharma companies and FDA to do randomised trails here ?