Following are public and technical abstracts for the Tumor Penetrating Oligomicelles project funded by the Department of Defense Kidney Cancer Research Program (KCRP) for 2017.
Principal Investigator: Arun Iyer
Institution: Wayne State University
Funding Mechanism: Idea Development Award — Early Career Investigator
Award Amount: $611,475
Public Abstract
Renal Cell Carcinoma (RCC) is the most common form of kidney cancer and remains one of the 10 leading causes of cancer death in the US. In 2017, 63,990 people are estimated to be diagnosed with RCC, and about 14,400 people are estimated to die from this disease. In addition, kidney cancer affects military personnel and their dependents and Veterans. The insult to the body during active military duty may cause kidney cancer but may not appear until later in life therefore affecting Veterans more frequently than their US civilian counterparts. The economic burden of RCC is also significant. Approximately $3.8 billion (B) is spent annually on its treatment with the projected costs reaching $5.3B for the year 2020.
RCC is difficult to treat as the cancer is largely resistant to many current therapies. RCC is also generally diagnosed at the late stages, when the tumors have grown larger. Thus, newer (combination) targeted therapies, including better ways of drug delivery and imaging, is urgently needed to effectively combat this malignant disease. In this regard, our strategy is to design and develop a cancer multicomponent targeting nanotechnology-based library approach. The tumor multicomponent targeting nanoformulations will be co-loaded with unique drug combinations that can work in synergy, with multiple modes of action including rejuvenating the body’s own immune system to effectively fight the cancer. Our preliminary data based on this concept is very promising and the proposed project will involve further critical evaluation of the nanoformulations to validate our initial findings that can result in improved drug delivery efficiency, efficacy, and safety in animal models that can be applied for future clinical translation. This project is thus expected to result in new directions for kidney cancer therapy and diagnosis that would ultimately benefit Veterans and civilians with RCC.
Technical Abstract
Background: Renal cell carcinoma (RCC) is the major (>90%) and most lethal form of the kidney cancers. RCC has high therapy resistance and a metastatic index with a 5-year disease-free progression at less than 10%. Thus, developing efficacious treatment remains an urgent and unmet need for therapy-resistant RCCs.
Areas of Emphasis: The proposed studies are focused on developing targeted therapies for treating resistant RCCs using combination drugs that work in synergy and can interrogate the tumor microenvironment such as tumor stroma, tumor hypoxia, and tumor-associated macrophages resulting in significant therapeutic benefit.
Hypothesis and Objectives: We will establish and validate a library of tumor-penetrating oligo-micelles (OMs) of varying (nano)size, shape, and surface properties to overcome delivery barriers to effectively reach the tumor tissues and hypoxic tumor core. We will utilize three unique tumor microenvironment selective markers (overexpressed at >90% in tumors compared with benign tissues) that include carbonic anhydrase-9 (CA9), for targeting tumor hypoxic regions; FR-alpha for targeting cancer epithelial cells; and FR-beta for targeting tumor-associated macrophages (TAM). We will engineer OMs to deliver a combination of multi-RTK-inhibitor Cabozantinib (CB) with our own apoptosis inducer/CARP-1 protein activator CFM-4.16 (C4.16). Finally, we will test these OMs for overcoming drug resistance and reprogramming of TAMs for effective RCC therapy.
Specific Aims and Study Design
Aim 1: Copper-free “click” chemistry-based synthesis of stepwise disintegrating OM library with dual CA9 and FR-alpha/beta targeting ligand to deliver combination drug payload. We will synthesize: (i) a library of oligomers with a terminal azide (N3) containing variable tumor extracellular and intracellular stimuli-responsive, or anti-fouling linkers functionalized with dual Acetazolamide (ATZ) and folic acid (FA) (the ligands targeting CA9 and FRalpha/beta respectively) and (ii) a library of N3-reactive DBCO functionalized polymer/lipid micelles encapsulated with C4.16 or CB. Finally, we will couple DBCO-C4.16/CB micelles with N3-FA-ATZ oligomers using the copper-free ‘click’ reaction to yield a variable library of nano-sized and -shaped FA-ATZ-C4.16 and FA-ATZ-CB OMs.
Aim 2: Demonstrate the synergistic cell killing effect, reversal of drug resistance, and macrophage modulation of dual hypoxia and stroma targeting OMs containing combination drugs. We will validate the strategy of RCC epithelial, hypoxia, and macrophage-targeted combination therapy in a larger number of cellular models and interrogate the mechanism of drug resistance. Clinically, Everolimus resistance (Evr-res) is an emerging phenomenon. Thus, we will use Evr-res RCC cells to find the effectiveness of the OMs and to identify best “hits” based on the reversal of drug resistance and down-modulation of TAM. Our preliminary in vitro data revealed a synergistic combination index for CB and C4.16, while an excellent tumor hypoxic core penetration by FA-ATZ oligomer was seen in the RCC spheroid model. Thus, we will establish (i) the synergistic anti-cancer effect, (ii) the role of pro-tumorigenic anti-inflammatory M2-macrophages in tumor immune evasion, and (iii) the cross-talk mechanism between RCC epithelial cells and M2-macrophages using FA-ATZ-C4.16 + FA-ATZ-CB OMs. We will use tumor spheroid and trans-well culture models to establish the proof-of-concept studies.
Aim 3: Demonstrate anti-tumor efficacy of FA-ATZ-C4.16 and FA-ATZ-CB OMs in drug-resistant orthotopic and PDx model of RCC. We will test a drug-loaded combination regimen in tumor models that closely mimic resistant human RCC followed by a detailed molecular analysis of residual tumors to interrogate the mechanism of drug resistance and inhibition of M2 macrophage function to support the therapeutic potential of OMs. We will determine the anti-tumor efficacy of the OM combination by utilizing three models: [A] the orthotopic model using RCC cells that will be injected within the subrenal capsule of the humanized CD34+ NSG mice and [B] the patient-derived sc xenograft (PDx) tumor model, which closely mimics human tumors. For this purpose, we will use [C] the TM00387 model (Jackson labs), which represents metastatic RCC and grows in NOD-SCID mice.
Innovation: We envisage that the rational design of series of OMs with tumor stimuli-responsive linkers using reagent-free “click” synthesis will afford versatile OM formulations with high stability in circulation, tumor selective delivery, and targeted release of cargo in the tumor microenvironment. The dual ligand containing OMs with tumor-multicomponent targeting will enable binding and penetration of the OMs into the tumor tissues as well as tumor immune cells resulting in improved drug delivery efficiency with better therapeutic efficacy. The new generation of OM library will result in the opening up of new paradigms for therapy-resistant RCCs with high future clinical translational potential.
Impact: This application brings together a team of scientists with diverse expertise to advance a new tumor-penetrating OM library strategy designed to deliver a combination of drugs that are expected to work in synergy via novel mechanisms involving the immune-oncology pathways that will overcome therapy resistance to RCC.