Doctor said Ironotecan doesn't work as well as the hipe.

I recently asked my dad's onc about Ironotecan and she said that it doesn't work as well as previously thought and this is why it wasn't given to my dad. Has anyone else heard this? I am only suspicious because of how she paused and looked at me when I asked. I asked again and she is always c oming up with week excuses as to why he shouldn't have it.
Thank everyone for any info you may have.
Karen