Chloroquine/hydroxychloroquine would be the other likely candidates. A quick web search suggests they've been tested and found ineffective for Babesia. Of course, their being found ineffective for treating a disease in a scientific study does not always stop people from trying them.

There's a mouse study from 2019 suggesting ivermectin is likely to be effective against Babesia, but it is not a standard treatment as far as I can tell.

That's what I though but it's not mentioned as a standard treatment.