Hi Alice,
Thiotepa has been around a very long time and was one of the first drugs used intravescially for bladder cancer. It's used in breast cancer, and others, in combination mostly.
It has fallen out of favor for superficial blc because many reports said it tended to give systemic side effects, something that is not supposed to happen with intravesical treatments.
Have you had this one, or are you considering it? I know that Dr. Lamm used to use it for low to intermediate risk tumors that didn't require BCG, but I think he's since changed to other drugs.
I think it may be one of the least expensive intravesical chemo drugs because it's been around so long.
Best wishes,
Wendy