ProQR Therapeutics recently received EMA and FDA orphan drug designation for their therapy targeting Cystic Fibrosis. ProQR Therapeutics are developing an antisense oligonucleotide that targets the F508del Cystic Fibrosis mutation. This is currently in the pre-clinical stage.
This approach is different to the CFTR modulation approach (potentiators and correctors), which targets the defective protein. CF gene mutations are present in the DNA, this defect is copied into the RNA, which is copied into the protein. ProQR are targeting the Cystic Fibrosis defect at the RNA level. This means the normal CFTR protein is made from the RNA, restoring chloride transport.