Sorry just wanted to clear this up - do you mean it delivers an extra set of DNA that does its thing alongside what is already there, rather than editing the main sequence like CRISPR wants to?
Yes, cDNA is a DNA fragment that does not interact with the patient's DNA in this treatment.
Wikipedia:
"Once amplified, the sequence can be cut at each end with nucleases and inserted into one of many small circular DNA sequences known as expression vectors. Such vectors allow for self-replication, inside the cells, and potentially integration in the host DNA. They typically also contain a strong promoter to drive transcription of the target cDNA into mRNA, which is then translated into protein."
The usual term for this is "nonintegrating" meaning the virus (or whatever delivery mechanism) does not insert itself (or anything) into the cell's genome. (Some viruses do this to help them proliferate - and they do it crudely which increases cancer risk, - but some don't because it's added complexity to have this "feature".)