For some reason I can’t reply to your topic so I had to start a new one.
I’ve used chlorambucil for our cat with lymphoma in pill form, compounded by Diamondback Pharmacy in Arizona. I can’t remember how much it cost, but it wasn’t prohibitive and much, much less than the brand name.
I never used the Leukeran, so I can’t compare effectiveness, but our vet was perfectly confident in prescribing it.
It was a little hard on our kitty – he had loss of appetite and nausea with it. We adjusted the dosing and also gave him antinausea meds and it helped. He also had increased white blood cell counts sometimes. I know other people who have used it with no side effects at all. Most cats tolerate it pretty well.