Project 3: Identifying Molecular Vulnerabilities to Improve Interferon Gene Therapy in Bladder Cancer

ABSTRACT Nadofaragene firadenovec (nadofaragene) is a combination of an adenovirus encoding human interferon-alpha (IFNα) and a detergent excipient (Syn-3) that facilitates gene transfer into the bladder urothelium. It was developed for the adjuvant intravesical treatment of patients with high-risk non-muscle invasive bladder cancer (NMIBC) and recently received FDA approval for the subset who have BCG unresponsive disease. Our group was responsible for developing nadofaragene from bench to bedside, taking it through proof-of-principle preclinical studies through Phase I-III clinical trials. The drug’s dosing schedule (once every 3 months) is advantageous as compared to other therapies, and its single-agent activity was superior to other approved and investigational agents. In published preclinical studies we reported that IFNα directly causes cell death in some bladder cancer cell lines via autocrine production of TRAIL (TNFSF10) and inhibits orthotopic tumor growth via inhibition of angiogenesis, and it strongly upregulated T-cell and checkpoint proteins in syngeneic murine models and urine collected from patients enrolled in the Phase-I clinical trial. Here we propose to define nadofaragene’s molecular mechanisms much more deeply and comprehensively. Our hypothesis is that luminal-basal molecular subtype lineage plasticity plays a major role, and we will exploit novel preclinical models and human specimens to test this hypothesis. In Specific Aim 1 we will use a panel of human organoid models to validate the observation we have made in conventional cell lines that luminal cancers are more sensitive to nadofaragene direct cytotoxicity, and we will perform mechanistic studies to define the molecular mechanisms involved. In Specific Aim 2 we will compare the effects of adenoviral IFN on the tumor immune landscapes in spontaneous murine models of luminal and basal cancer that were developed by our collaborators in Project 2, and in Aim 3 we will perform longitudinal urine samples and whole organ analyses of the effects of nadofaragene in patients, exploiting the unique expertise of Project 1’s investigative team. The results of this work will help us to identify biomarkers that predict response or resistance and novel candidate drugs to combine with nadofaragene to expand its therapeutic activity.