I don't know the specifics of efforts to "repair" DNA replication repair (if you get my drift), but I suspect there is some effort in that area.

There definitely are efforts to correct enzymes involved in tumor-suppression (p53 is probably the best known tumor suppressor protein). e.g., here's a study on a small molecule designed to correct mutated p53 https://pmc.ncbi.nlm.nih.gov/articles/PMC8099409/