What's in it for Gilead? Remdesivir is the only antiviral for...

What's in it for Gilead? Remdesivir is the only antiviral for Covid on the market. Gilead have an EUA so people can use it. They own the IP. Countries are buying as much as they can make. Why spend money on a new version? They would need to start from scratch. What dose? Are there extra side effects or less side effects?
What's in it for those taking part in the trial? You could get remdesivir as part of the EUA that we know can be effective and these are the side effects. Or you could take part in a trial that will give you the same drug with different pharmacokinetics that we are unsure how effective it will be or what side effects you may experience.