Abstract 1831: A long-acting and CD122-enhanced IL-2 analog, HM16390, synergizes with immune checkpoint inhibitor by remodeling an immune cell profile in tumor microenvironment

• Published in: Cancer research (Chicago, Ill.) Vol. 83; no. 7_Supplement; p. 1831
• Main Authors: Choi, Jaehyuk, Kim, Jinyoung, Kim, Yu Yon, Jeong, Seongju, Bae, Sungmin, Kim, Daejin, Choi, In Young
• Format: Journal Article
• Language: English
• Published: 04.04.2023
• ISSN: 1538-7445; 1538-7445
• DOI: 10.1158/1538-7445.AM2023-1831

Abstract Immune checkpoint inhibitors (CPI) are widely used for cancer immunotherapy. However, the response to CPIs is dependent on phenotype of tumor microenvironment (TME). A cold tumor known as immune-excluded or -desert has shown poor response to CPIs due to an absence of effector T cells in TME. IL-2 analog, which is immune stimulator and able to recruit cancer-fighting cells into TME, may be promising therapeutic partner for overcoming a limitation of CPIs. Previously, HM16390, a long-acting CD-122-enhanced IL-2 analog, exerted dose-dependent anti-tumor activity in low immunogenic B16F10 melanoma mice. Here, we further investigated the immune cells composition in TME following HM16390 treatment and synergistic anti-tumor effect after combination with CPI. B16F10 mice were sacrificed at days 1, 3, and 8 following single subcutaneous administration of HM16390 or 5 consecutive daily administrations of aldesleukin. According to the result, HM16390 transiently increased peripheral cytokines (IFNγ and TNFα) more than aldesleukin. In line with this, we observed that the tumor-infiltrating NK/Treg ratio was significantly increased approximately 19 by treatment of HM16390 while showing 4.2 in aldesleukin treated group at Day 3. Furthermore, tumor-infiltrating CD8+/Treg ratio was also upregulated approximately 74 by treatment of HM16390 while only showing 6.1 in aldesleukin treated group at Day 8. Significantly increased pro-inflammatory molecules such as GrzB and IFNγ were also observed in HM16390 treated group compared to aldesleukin (p<0.01 and p<0.001, respectively). Next, we investigated synergistic anti-tumor effects in combination with CPI. B16F10 mice were repeatedly given HM16390 once a week or aldesleukin 5 consecutive days per week with or without mouse anti-PD1. After four weeks treatment, 25% of B16F10 mice showed complete response by treatment of HM16390, and significantly increased up to 88% by combination with anti-PD1. However, none of the mice showed complete response by treatment of aldesleukin/anti-PD1 combo. In conclusion, HM16390 effectively induced tumor growth inhibition through the activation and tumor infiltration of cytotoxic lymphocytes. This favorable immune alteration in tumor elicited a TME remodeling in which CPI could sufficiently respond. Citation Format: Jaehyuk Choi, Jinyoung Kim, Yu Yon Kim, Seongju Jeong, Sungmin Bae, Daejin Kim, In Young Choi. A long-acting and CD122-enhanced IL-2 analog, HM16390, synergizes with immune checkpoint inhibitor by remodeling an immune cell profile in tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1831.