Gene therapy studies of cystic fibrosis (CF) have shown ing capacity. Functional analyses showed that the new that AAV-based vector was efficient in transferring but not vectors were packaged efficiently and expressed higher in expressing the CFTR cDNA in the target cells. The levlevels of CFTR than a vector in which the CFTR gene was els of CFTR gene expression were limited by the small driven by the ITR sequence of AAV. Transduction of airway packaging capacity of AAV because it had been difficult to epithelial cells containing ٌ508 mutation with the new vecpackage the CFTR cDNA with an efficient promoter. In the tors demonstrated efficient expression of the wild-type present study we have developed a new generation of CFTR and correction of the CF phenotype. In contrast, no AAV/CFTR vectors which contain efficient short promoters significant CFTR expression was detected in cells infected to express the CFTR gene in target cells. To do so, we with the vector that express the CFTR gene from the ITR. reduced the size of the CFTR cDNA by determining the These findings support the notion that the AAV can be minimal untranslated regions required for expression of developed into an efficient vector to transduce the CFTR CFTR cDNA. We also identified short and efficient progene and vectors expressing higher levels of CFTR from moters that could be packaged with the down-sized CFTR an efficient promoter should provide better efficacy for cDNA into a novel AAV vector that had a maximal packaggene therapy of cystic fibrosis.

A central challenge for any therapeutic is targeting diseased over normal cells. Proteolysis is frequently upregulated in disease and can generate proteoforms with unique neo-epitopes. We hypothesize that targeting proteolytic neo-epitopes can enable more effective and safer treatments, reflecting a conditional layer of disease-specific regulation. Here, we characterized the precise proteolytic isoforms of CUB domain containing protein 1 (CDCP1), a protein overexpressed and specifically cleaved in RAS-driven cancers. We validated that the N-terminal and C-terminal fragments of CDCP1 remain associated after proteolysis in vitro and on the surface of pancreatic cancer cells. Using a differential phage display strategy, we generated exquisitely selective recombinant antibodies that target cells harboring cleaved CDCP1 and not the full-length form using antibody-drug conjugates or a bi-specific T-cell engagers. We show tumor-specific localization and anti-tumor activity in a syngeneic pancreatic tumor model having superior safety profiles compared to a pan-CDCP1-targeting antibody. Our studies show proteolytic neo-epitopes can provide an orthogonal AND gate for disease-specific targeting.