Just wondering, how can we sell off leronlimab for

Just wondering, how can we sell off leronlimab for GVHD(or any indication) when the same product works for so many different indications? Wouldn't this product then be available for all the other indications through over the counter purchase. How would profits be split up if they were bought off brand? I know some of my lingo is probably off, so I'm hoping craigakess doesn't tear into me to bad.