Next Generation CAR NK Combinatorial Immunotherapy against Osteosarcoma
Over the past decades, despite multiple therapeutic approaches, children, adolescent and young adults with poor risk osteosarcoma (OSA) have a dismal outcome (<20% overall survival). Novel therapeutic approaches are urgently needed. NK cells constitute a promising alternative therapy for OSA. Expanded NK cells treated dogs with OSA reduced tumor cell migration to other organs and significantly improved animal survival. The density of activated NK cells in the peripheral blood correlates with survival in patients with OSA. However, patients with OSA have a significant reduction in NK numbers and function due to multiple challenges faced by NK cells in the OSA tumor microenvironment (TME) (tissue). Multiplex gene modification will likely be required to develop highly effective NK cell-based immunotherapies. Recently, base editors (BEs) which induce precise DNA base alterations, have been utilized to knock out proteins that inhibit NK, resulting in significantly enhanced NK function. BE is highly efficient for multiplex gene editing and can be coupled with gene engineering to produce multiplex modified NK cells that express a receptor (CAR) which recognize tumor surface proteins or chemokine receptors that are attractive to tumor.
Furthermore, we and others have demonstrated that NK cell persistence, metabolic fitness, and function can be enhanced through immune modulators including cytokines (IL-15) or agonists that mimic biological functions and monoclonal antibody (Dinutuximab) targeting OSA surface protein GD2. Therefore, we hypothesize that multiplex modified NK cells created by gene engineering and multiplex base editing combined with anti-GD2 antibody and IL-15 agonist will enhance NK tumor targeting, TME infiltration, persistence and anti-tumor activity in OSA. Our aims are 1) develop and investigate nonviral engineered NK cells expressing a receptor (CAR) and/or chemokine receptor (CXCR2) following multiplex base editing of NK cells for NK inhibitory protein knockout against OSA; 2) determine the anti-tumor activity of the optimal NK cells in Aim 1 combined with dinutuximab and NKTR-255 (IL-15 agonist) against OSA.
To achieve the aims, we will use novel and innovative approaches including 1) creation of next generation NK cells using multiplex base editing coupled with nonviral engineering; 2) incorporating a receptor against a novel OSA surface protein target to enhance NK specific targeting; 3) increasing NK tumor homing by engineering NK cells to express a tumor attracting receptor; 4) using a novel IL-15 agonist and an anti-GD2 antibody to improve NK cell persistence and function. If successful, this translational study will identify a combinatorial immunotherapy strategy that overcomes OSA TME resistance and improves NK cell efficacy against OSA which may ultimately lead to the delivery of a highly effective immunotherapy regimen for the treatment of patients with poor risk OSA.