I think you have this backwards. If people are taking ivermectin for cancer instead of immunotherapy, then the pharmas are definitely loosing money. A single treatment of Keytruda costs around $25,000. A standard regimen is one every three or four weeks. And these treatments can go on for years. (yes, I know people personally who have been taking Keytruda for several years)
Similar story for monoclonal antibodies. They often cost over $100,000 per year
For other chemo drugs, it varies. Xeloda, doxorubicin, cisplatin (in IV form), cyclophosphamide, and others are all reasonably priced, most around $1 to $10 per pill, it seems.
It’s also worth noting that a standard course of treatment for cancer will usually combine several different drugs.
Ivermectin, on the other hand, costs a dollar or two per pill at most, and could be less than a dollar each.
That’s not true. It’s rare to find a drug that only has one effect in a body. And Ivermectin is no exception. There are quite a few potential and several demonstrated uses for it. Whether it is curative for cancer, and which types, is still an open question - which is to say that there have been no large clinical trials done to answer the question.