GX-I7(rhIL-7-hyFc, efineptakin alfa), a long-acting IL-7, safely and effectively increased peripheral CD8+and CD4+T cells and TILs in patients with solid tumors

ABSTRACT Purpose GX-I7 (rhIL-7-hyFc, efineptakin alfa) is a hybrid Fc-fused long-acting recombinant human interleukin-7 (IL-7) developed by Genexine, Inc. with the aim of correcting T-cell deficiency, thereby strengthening the immune response to fight against cancer. This Phase 1b trial ( NCT03478995 ) was designed to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of GX-I7 in patients with locally advanced or metastatic solid tumors. Methods This study consisted of two phases: dose-escalation and expansion. Eight dose groups were administered GX-I7 intramuscularly at doses ranging from 60 to 1700 μg/kg every three or six weeks. Results All regimens were safe and well tolerated, with the most frequently reported adverse drug reactions being injection site reactions, which were manageable with or without pharmacological intervention. GX-I7 demonstrated dose-dependent increases in the maximum serum concentration (C max ) and area under the curve up to the last measurable concentration (AUC last ). In addition, a dose-dependent increase in circulating CD8 + /CD4 + T cells was observed. In five patients who consented for biopsy, a statistically significant increase in tumor-infiltrating CD8 + /CD4 + T cell lymphocytes after GX-I7 treatment was observed. Conclusion These findings support the use of GX-I7 as a safe and effective T cell-amplifying agent capable of correcting T cell deficiencies. GX-I7 is expected to result in better clinical outcomes when used in combination with other anti-cancer agents by creating a better environment for immune checkpoint inhibitors and anti-cancer treatments to fight cancer.