We call this indication creep
Pharma company develops a drug for a condition, markets it, it works. Then, the revenue stream is in place. But the company has a fiduciary responsibility to shareholders to make more money, so they try to use it on other diseases that are not studied and do not have anywhere near the same stringent criteria for interpreting data and efficacy as they do for developing the drug
Them they send the reps into medical clinics and try to convince doctors to use the medications for conditions with very tenuous data to support the use.
Literally yesterday I had a lady pitching rifaxamin for IBS. We asked her about head to head comparisons. They don’t exist. Of course they don’t exist, but it was funny to hear the medical resident ask and see her reaction nonetheless