Hey Mate, I think the answer to your question can be found in...

Hey Mate, I think the answer to your question can be found in this paragraph.
The ability to treat difficult-to-access tumor's, such as pancreatic and liver cancers, by delivering CF33 trans-arterially may be valuable to cancer patients compared to traditional administration methods where dense fibrous tissue and lack of blood vessels supplying the tumor's have been shown to limit therapy uptake.
Reading this paragraph suggests to me that the issue is that fibrous tissue and lack of blood vessels obviously inhibits and restricts the effectiveness of CF33 to access the tumor, so by a delivering it Trans-arterially rather than conventional/traditional methods it will pack a lot more punch.
Looks like a great partnership to me.