Designer Cytokine Therapy of Hepatocellular Carcinoma

PROJECT 4: SUMMARY Innovative therapeutic strategies are warranted to treat hepatocellular carcinoma (HCC), which is one of the most common malignancies worldwide with current approaches being inadequate in accomplishing the ultimate goal of curing this aggressive cancer. The focus of our project is to address this need and develop

improved molecular medicine(s) that selectively and specifically suppress primary liver tumor(s) and stimulate enhanced immune responses to eliminate distant metastatic tumors. MDA-7/IL-24, a unique therapeutic cytokine (secreted protein therapeutic) discovered in our laboratory, displays multifaceted anti-tumor properties

and confirmed safety and efficacy in a Phase I clinical trial in patients with advanced cancers following direct administration in a replication-incompetent adenovirus (Ad.5-mda-7). Mechanism of action studies indicate that MDA-7/IL-24 has profound anti-cancer activity, which occurs by direct induction of apoptosis and toxic

autophagy, inhibition of angiogenesis, enhanced recognition of cancer cells by the immune system, potent “bystander” anti-tumor activity affecting both primary and metastatic cancers, and synergy with conventional therapies (including radiation, chemotherapy, antibody-based therapy, and immunotherapy). Using a genetic

engineering strategy, we developed and provide proof-of-principle that the next generation of MDA-7/IL-24, M7S/IL-24S, is superior in comparison with wild-type protein. In Aim 1, we engineered a fusion protein (IL- 24S/IL-15) with IL-24S and IL-15 to create an immuno-enhancing Fusion Superkine, FSK. Both IL-24S and IL-

24S/IL-15 will be incorporated in a cancer-selective conditionally replication-competent cancer terminator virus (CTV) that is predicted to have superior anti-cancer attributes. In Aim 2, we will examine the efficacy of natural killer (NK) cells expressing our modified/Fusion Superkine. Experiments will evaluate the feasibility of cell-

based therapies of HCC using these designer cytokine proteins in a single moiety, IL-24S/IL-15, which will elicit both tumor-killing and immune modulatory effects along with NK-mediated cytotoxicity. In Aim 3, to accurately target and deliver therapeutic payloads to the liver, we will use a novel state-of-the-art delivery strategy that

involves temporarily and non-invasively altering permeability of the liver using empty microbubbles (MBs) and focused ultrasound (FUS) and then delivering the therapeutic in a second MB and releasing it in the liver with FUS, i.e., the focused ultrasound double microbubble delivery (FUS-DMB) approach. Once the parameters for

efficient delivery of viruses to the liver are optimized, we will evaluate the activity of our therapeutics to treat HCC. To improve activity of our CTV expressing FSK, a combinatorial regimen will be established with Standard of Care or investigational drugs using multiple authentic HCC pre-clinical animal models. Successful

completion of the goals of our research offer opportunities to effectively treat HCC non-invasively. Accomplishing these goals would result in a paradigm shift in how patients with liver cancer are clinically managed.