Project Summary:
Pancreatic ductal adenocarcinoma (PDA) is a highly lethal cancer with a 5-year survival rate less than 9%.
New treatments for PDA that are both safe and effective are needed. Currently, chemotherapy (e.g.
gemcitabine, nab-paclitaxel) is the preferred treatment, as the tumors in majority of patients (80%) are
surgically non-resectable at initial diagnosis. However, even these therapeutic choices have limited efficacy
because of the highly immunosuppressive tumor microenvironment and poor tumor penetration due to low
density of blood vessels and dense stroma. To overcome these treatment obstacles, the applicant recently
developed an immunochemotherapy regimen based on co-delivery of gemcitabine (GEM), paclitaxel (PTX)
and indoleamine 2, 3-dioxygenase 1 (IDO1) inhibitor NLG919 through a PGEM nanocarrier. Preliminary data
showed that the PGEM carrier penetrated to the core of experimental tumors, and, importantly, both
hydrophilic GEM and multiple hydrophobic agents with distinct properties could be loaded onto PGEM micelles.
Indeed, PGEM co-loaded with PTX and NLG919 induced an improved anti-tumor immune response and was
highly efficacious in inhibiting tumor growth in PANC02 xenograft model, most likely through a synergistic
tumor killing effect of PTX and GEM, as well as the effect of NLG919 in reversing IDO-mediated
immunosuppression. In this application, the applicant proposes to further improve the PGEM carrier by
optimizing the units of each constructing motif (Aim 1). In addition, the applicant will test the in vivo targeting
efficiency of different PGEM nanocarriers using tumor models that closely mimic human PDA. The
pharmacokinetics, biodistribution and penetration of the nanoformulations (Aim 2), as well as their therapeutic
effect and the underlying mechanism (Aim 3) will be evaluated.
The successful completion of the proposed aims will not only provide an effective regimen for improved
PDA immunochemotherapy, but also provide a carrier platform that can be extended to targeted co-delivery of
multiple distinct hydrophilic and hydrophobic agents for various combination therapies.