Advancing pancreatic cancer therapy by mesothelin-specific nanobody conjugation

Pancreatic adenocarcinoma (PAAD) is highly challenging to treat due to its poor prognosis and limited effective treatment options. Liposomal nanotechnology has emerged as a promising drug delivery platform in oncology, but existing liposomal therapies face limitations such as systemic toxicity, insufficient tumor selectivity, and low target specificity. Mesothelin (MSLN), an antigen overexpressed in PAAD, has attracted attention as a potential target for precision therapy. Here, we present the development of an anti-MSLN nanobody (D3 Nb) with high binding affinity (K_D = 2.2 nM) that can selectively bind to MSLN-positive cancer cells. Structural analysis revealed that hydrophobic and hydrogen bonds within the complementary determining region (CDR) of D3 Nb promote strong binding to MSLN, leading to significant inhibition of AKT/NF-κB signaling and downregulation of fibronectin 1 (FN1) and twist1, key drivers of PAAD oncogenicity. In vivo studies confirmed that D3 Nb alone inhibits tumor progression. Furthermore, selective delivery to MSLN-positive tumors in combination with gemcitabine-loaded liposomes (D3-LNP-GEM) significantly improved cytotoxicity and promoted tumor regression. These findings highlight the potential of the D3-LNP-GEM platform as a novel targeted therapy for MSLN-expressing malignancies, showing promising efficacy in preclinical models and paving the way for continued clinical evaluation.