Blockade of immune checkpoints in lymph nodes through locoregional delivery augments cancer immunotherapy

• Authors: Edmund Waller, Emory University; David M Francis, Georgia Institute of Technology; Margaret P Manspeaker, Georgia Institute of Technology; Alex Schudel, Georgia Institute of Technology; Lauren F Sestito, Georgia Institute of Technology; Meghan J O'Melia, Georgia Institute of Technology; Haydn Kissick, Emory University; Brian Pollack, Emory University; Susan N Thomas, Georgia Institute of Technology
• Journal Title: SCIENCE TRANSLATIONAL MEDICINE
• Volume: Volume 12, Number 563
• Publisher: AMER ASSOC ADVANCEMENT SCIENCE | 2020-09-30
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1126/scitranslmed.aay3575
• Subjects: Engineering, Chemical; Health Sciences, Pathology; Engineering, Biomedical
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cell Biology; Medicine, Research & Experimental; Research & Experimental Medicine; CD8(+) T-CELLS; TUMOR RESPONSES; PD-1 BLOCKADE; MONOTHERAPY; ANTIBODIES; EFFICACY; THERAPY; GROWTH; CTLA-4; SITE

Abstract

Systemic administration of immune checkpoint blockade (ICB) monoclonal antibodies (mAbs) can unleash antitumor functions of T cells but is associated with variable response rates and off-target toxicities. We hypothesized that antitumor efficacy of ICB is limited by the minimal accumulation of mAb within tissues where antitumor immunity is elicited and regulated, which include the tumor microenvironment (TME) and secondary lymphoid tissues. In contrast to systemic administration, intratumoral and intradermal routes of administration resulted in higher mAb accumulation within both the TME and its draining lymph nodes (LNs) or LNs alone, respectively. The use of either locoregional administration route resulted in pronounced T cell responses from the ICB therapy, which developed in the secondary lymphoid tissues and TME of treated mice. Targeted delivery of mAb to tumor-draining lymph nodes (TdLNs) alone was associated with enhanced antitumor immunity and improved therapeutic effects compared to conventional systemic ICB therapy, and these effects were sustained at reduced mAb doses and comparable to those achieved by intratumoral administration. These data suggest that locoregional routes of administration of ICB mAb can augment ICB therapy by improving immunomodulation within TdLNs.